DIY Skincare Ingredients: From Raw Materials to Real Formulation

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Every skincare formula starts with its ingredients — but choosing them is about much more than finding an oil, butter or botanical extract that sounds good.

Each ingredient has a job to do. Some create structure, some influence skin feel, some help oil and water stay together, while others help protect a formula from oxidation or microbial growth. Understanding those roles makes it much easier to move from simply following recipes to making informed formulation decisions of your own.

I know how quickly ingredient shopping can become overwhelming. There are hundreds of botanical oils, butters, waxes, extracts, emulsifiers, preservatives and active ingredients available — and when you are starting out, they can all sound like something you need. I’ve been there too, comparing ingredient descriptions and wondering which one actually belongs in the formula I want to make.

That is one of the reasons I created this guide. Instead of asking “Which ingredient is best?”, I want to help you ask more useful questions: What do I want this ingredient to do? Does my formula actually need it? How much should I use? What could I substitute if I don’t have it? And how will that choice affect the rest of my formula?

This guide brings together 18 essential DIY skincare ingredient groups, from botanical oils, butters and waxes to humectants, emulsifiers, antioxidants and preservatives. You’ll learn what each group contributes to a formulation, what to consider when choosing between ingredients, and how to use them more intentionally.

Research into commonly used cosmetic plant oils also shows why ingredient choice cannot be reduced to a simple list of skincare benefits. A scientific review of sweet almond, evening primrose and jojoba oils highlights the importance of oil selection, quality, stability and formulation context when considering their effects on the skin and epidermal barrier. Read the research on PubMed.

If you’re working specifically with plant materials, my Botanical Library explores botanical identity, herbal energetics, extraction methods and seed oils before those materials enter a formula.

From Ingredient Knowledge to Better Formulation

Knowing what an ingredient is does not automatically tell you how to use it.

A lightweight botanical oil and a rich butter may both act as emollients, but they can create very different textures and sensory profiles. An emulsifier needs to suit the type of emulsion you are making. Water-based formulations require an appropriate preservation strategy, while antioxidants can help slow the oxidation of susceptible oils but do not replace preservatives.

This distinction is particularly important in DIY skincare. A 2023 literature review comparing homemade skincare with manufactured products highlights some of the limitations of home remedies, including unknown ingredient quantities, lack of appropriate preservation and the use of materials that may not have been tested for topical application. Read the CosmoDerma review

That is why throughout this guide I look at ingredients through their function, formulation requirements and practical use, rather than treating them as a list of isolated skincare benefits.

You’ll also find links to my more detailed ingredient guides and, where useful, ingredients and formulation supplies you can explore for your own projects. You certainly don’t need to buy everything. Start with the ingredients required for the type of product you actually want to formulate and build your collection as your skills grow.

When you’re ready to put that knowledge into practice, continue to DIY Skincare Recipes to learn the formulation process, or visit the DIY Skincare Recipe Library to choose a formulation and calculate your own batch.

The Foundation of DIY Skincare Ingredients

Oils, butters, waxes and hydrosols are often where DIY skincare formulation begins. But even ingredients from the same family can behave very differently in a formula. Their composition, stability, texture and skin feel can all vary.

Let’s look at what makes them different — and how to choose the ones that make sense for the product you want to formulate.

Carrier Oils

Carrier oils are one of the most versatile ingredient groups in DIY skincare. They can form the entire base of a facial or body oil, or become part of the oil phase in balms, creams, lotions and other formulations.

But choosing an oil is about more than matching it to a skin type. Different oils vary in their fatty acid composition, skin feel, absorption speed and oxidative stability. A lightweight oil that works beautifully in a facial serum may not give you the texture or stability you want in a balm or body product.

How Do You Choose a Carrier Oil?

Start with the product you want to make and the role you want the oil to play.

For a lighter skin feel, you might explore faster-absorbing oils. For richer formulations, you may prefer oils that create a more substantial feel on the skin. If your formula contains a high percentage of oxidation-sensitive oils, you’ll also need to think about shelf life and how you store the finished product.

You can explore these differences in more detail in my Botanical Oil Guide, or compare individual oils in the Botanical Oil List.

If you want to understand why oils behave differently, my guides to fatty acid profiles, iodine number and unsaponifiables in botanical oils take you deeper into their composition and stability.

You can also compare refined oils with unrefined oils, or explore upcycled oils if sourcing and the use of food-industry by-products are part of your ingredient selection.

How Many Oils Do You Actually Need?

Probably fewer than you think.

It’s easy to build a collection of beautiful botanical oils and end up using only a few of them regularly. Instead of buying several oils with very similar properties, start with a small selection that gives you different formulation options.

You might choose one lighter oil for facial oils and serums, another with a richer skin feel for balms or body products, and then add more specialized oils when a particular formulation gives you a reason to use them.

As you gain experience, your oil collection can grow with your formulations — rather than the other way around.

If skin feel is one of your priorities, my guide to fast-absorbing oils can help you narrow down your options.

Explore Botanical Oils

Not sure which oil to try next? These individual ingredient guides take a closer look at their composition, skin feel and potential uses in skincare formulations:

• Jojoba Oil
• Argan Oil
• Watermelon Seed Oil
• Coffee Oil
• Blueberry Seed Oil
• Plum Kernel Oil
• Tomato Seed Oil
• Cucumber Seed Oil
• Sunflower Seed Oil

For a broader comparison, visit my Botanical Oil Guide or browse the Botanical Oil List.

Shop Botanical Oils

Once you have a better idea of the type of oil your formula needs, you can compare available options from suppliers serving your region.

US: Browse botanical oils on Amazon
Europe: Browse botanical oils at Mireille Lab

Botanical Butters

Botanical butters bring richness, structure and a more substantial skin feel to many DIY skincare formulations. You’ll find them in balms, body butters, creams, lotion bars and other products where oils alone may not create the texture you want.

But not all butters behave the same way. They differ in hardness, melting behaviour, fatty acid composition and skin feel, which means choosing a butter can change much more than the ingredient list — it can change the texture and overall feel of the finished product.

How Do You Choose a Botanical Butter?

Start with the texture you want to create.

A harder butter can add more structure, while a softer butter can contribute richness without making the finished product quite as firm. Melting behaviour matters too, particularly in balms, body butters and solid products that need to remain stable during storage but still melt comfortably when applied.

Scent is another important consideration. Some unrefined botanical butters have a noticeable natural aroma that can become part of the scent of your finished product. Cocoa butter, for example, can bring its characteristic chocolate-like aroma, while other butters may have earthy, nutty or more subtle notes. If you want a more neutral base, the degree of refinement can therefore matter just as much as texture and skin feel.

You’ll also want to consider how the butter feels on the skin, how much you plan to use and what the other oils and waxes in your formula are already contributing.

How Many Butters Do You Actually Need?

Again, probably fewer than the ingredient catalogues suggest.

If you’re just starting out, one versatile butter can be enough for many formulations. Adding a second butter with noticeably different hardness or skin feel gives you more room to experiment without filling your ingredient cupboard with materials that perform very similar jobs.

As you formulate more products, you can explore less familiar butters when their particular properties give you a reason to use them.

Explore Botanical Butters

Want to see how individual butters differ? Start with these BYKM ingredient guides:

• Shea Butter
• Mango Butter
• Cocoa Butter
• Cupuaçu Butter
• Bacuri Butter

For a broader comparison, explore my Ultimate Guide to Botanical Butters or discover less familiar options in the Amazonian Butter Guide.

Shop Botanical Butters

Once you know what kind of texture and formulation role you need, you can compare botanical butters available in your region.

US: Browse botanical oils on Amazon
Europe: Browse botanical oils at Mireille Lab

Waxes

Waxes are mainly used to add structure, firmness and stability to anhydrous products such as balms, salves, lotion bars and solid skincare. They can also influence how a product feels during application and how well it holds its shape at room temperature.

Beeswax is probably the best-known option, but plant-based waxes such as candelilla, carnauba and sunflower wax give formulators alternatives with very different properties.

How Do You Choose a Wax?

Start with the texture and firmness you want in the finished product.

Some waxes create a softer, more flexible balm, while others can make a formula considerably harder even when used at a similar percentage. Also consider how easily the wax melts, particularly when making products that need to remain solid in warmer conditions.

Scent matters too. Beeswax can have a noticeable honey-like aroma, while some plant waxes have a much more neutral scent. This can make a difference in simple formulations such as lip balms and solid balms, where there are relatively few ingredients to mask the natural aroma of the wax.

The finish can also change. Depending on the wax and the rest of the formula, your choice can influence how glossy or matte the finished product looks and feels. This is especially noticeable in lip products and solid formulations where wax makes up a meaningful part of the structure.

Your choice may also depend on whether you want to formulate with beeswax or use a plant-based alternative. But choosing a plant wax is not simply a matter of replacing beeswax with the same amount of another wax. Firmness, melting point, scent and finish can all change, so the formula may need to be adjusted.

Keep in mind: These are general characteristics, not substitution ratios. Wax properties can vary by supplier and grade, and the final texture and finish also depend on the oils, butters and other ingredients in your formula.

Can You Substitute One Wax for Another?

Sometimes, but not always at the same percentage.

Beeswax, candelilla, carnauba and sunflower wax differ in their properties. Replacing one with another can change how firm the finished product becomes, how easily it spreads, its natural scent and even how glossy or matte it appears.

If you make a substitution, treat it as a formulation adjustment rather than a simple ingredient swap. Start with a small test batch and adjust the wax-to-oil ratio if necessary.

This is especially useful to remember when working with lip balms. My Natural Lip Balm guide shows how wax fits into a complete anhydrous formula.

Shop Cosmetic Waxes

Once you know what kind of structure you want to create, you can compare different cosmetic waxes and pack sizes before choosing one for your formula.

US: Browse botanical oils on Amazon
Europe: Browse botanical oils at Mireille Lab

Hydrosols

Hydrosols are aromatic waters produced during the steam or water distillation of plant material. They can replace part or all of the distilled water in products such as facial mists, toners, lotions, creams and other water-based formulations.

They bring more than scent to a formula, but they should not be chosen simply because a particular plant sounds suitable for a certain skin type. Their composition can vary depending on the plant material, distillation process and supplier.

How Do You Choose a Hydrosol?

Start with the product you want to formulate and the role the hydrosol will have in it.

Consider its aroma, supplier documentation, pH and recommended storage conditions. Scent is particularly important because some hydrosols have a much stronger or less familiar aroma than you might expect from the corresponding essential oil or fresh plant.

Quality matters too. Look for a supplier who provides clear botanical identification and useful technical information about the ingredient rather than relying only on marketing descriptions.

And because hydrosols are water-based ingredients, they also change the microbiological requirements of your formula.

Do Hydrosols Need a Preservative?

This is where hydrosols are very different from botanical oils and butters.

Once you use a hydrosol in a water-containing DIY formulation, you need to consider an appropriate preservation system for the finished product. A hydrosol does not preserve a formula simply because it comes from an aromatic plant.

The preservative needs to be selected for the complete formulation, including its pH, water content, other ingredients and the preservative supplier’s recommended usage conditions.

Explore Hydrosols and Aromatic Plants

If you want to explore some of the plants commonly used in aromatic skincare, continue with my individual botanical guides:

• Helichrysum italicum
• Rose in Skincare
• Lavender in Skincare
• Rosemary in Skincare

For a practical example of a water-based product, see my Hydration Mist.

Functional Ingredient Families

Once you move beyond oils, butters, waxes and hydrosols, ingredient selection becomes increasingly connected to function.

You may need an ingredient to soften the skin feel of a product, attract water, create an emulsion, cleanse, thicken a formula or help disperse an oil-soluble ingredient in water.

Understanding these functions makes formulation much easier because you stop choosing ingredients simply because they sound interesting and start asking a more useful question:

What does my formula need this ingredient to do?

The following ingredient families each solve a different formulation problem.

Emollients

Emollients can change the way a formulation spreads, feels and absorbs on the skin. While botanical oils and butters also act as emollients, formulators can use dedicated cosmetic emollients to fine-tune the sensory profile of a product.

Ingredients such as Coco-Caprylate/Caprate, Sensol 100 and Caprylic/Capric Triglyceride can be used to adjust properties such as slip, spreadability, richness and after-feel without relying only on botanical oils.

How Do You Choose an Emollient?

Start with the sensory profile you want to create.

Does your formula feel too heavy or greasy? Do you want it to spread more easily, feel lighter during application or leave a different finish on the skin?

This is where emollients become useful formulation tools. Two ingredients can perform a similar general function while creating noticeably different sensory results.

Your choice also depends on the product itself and the other ingredients already present in the formula. Instead of asking which emollient is “best,” consider what you want to change about the way your formulation feels and performs.

If you are still learning how different oil-based ingredients influence skin feel, my Fast-Absorbing Oils for Skin guide is a useful starting point for comparing lighter botanical oils.

Shop Cosmetic Emollients

US: Browse botanical oils on Amazon
Europe: Browse botanical oils at Mireille Lab

Clays

Cosmetic clays are more than ingredients for face masks. Depending on their mineral composition and properties, they can contribute to absorption, texture, cleansing and the overall feel of a formulation.

Kaolin, for example, behaves differently from smectite clays such as bentonite. This is why choosing a clay should involve more than simply matching a clay colour to a skin type.

How Do You Choose a Clay?

Start with what you want the clay to do in your formula.

Consider its absorption properties, particle characteristics and the type of product you are making. A clay that works well in a dry facial mask may not necessarily be the best choice for another type of formulation.

The mineral itself matters too. Research on clays in cosmetics shows that different clay minerals have different physicochemical properties and can perform different technological functions in cosmetic products. Read the research Cambridge

If you want to compare individual options, continue to my Best Clay for Face Masks guide.

Surfactants

Surfactants like SCI (Sodium Cocoyl Isethionate), Decyl glucoside, Coco-glucoside are the ingredients that make cleansing products such as facial cleansers, body washes and shampoos possible. They help water interact with oils, sebum and other materials so they can be lifted from the skin or hair and rinsed away.

But surfactants are not all the same. They can differ considerably in cleansing strength, foam, skin feel and compatibility with other ingredients, which is why choosing one simply because it is described as “natural” or “gentle” does not tell you enough about how it will behave in a formula.

How Do You Choose a Surfactant?

Start with the product you want to formulate.

A facial cleanser, body wash and shampoo do not necessarily need the same surfactant system. Think about the level of cleansing you need, the amount and type of foam you want, the desired skin feel and whether you are working with a liquid or solid product.

Surfactants are also often combined rather than used alone. A blend can help you adjust cleansing, foam and the overall sensory feel of the finished product.

You also need to check the supplier’s recommended usage rate, active surfactant matter, pH requirements and compatibility with the rest of your formula. This becomes particularly important when adapting a formula or replacing one surfactant with another.

Research on skin cleansing shows that surfactants help remove oils and impurities that water alone cannot effectively wash away. However, their cleansing strength and potential impact on the skin barrier depend on the type of surfactant and the overall formulation (Draelos, 2022).

Can You Substitute One Surfactant for Another?

Not necessarily.

Two surfactants may perform a similar general function but contain different amounts of active surfactant matter and behave differently in a formulation. Replacing one gram-for-gram can therefore change the cleansing strength, viscosity, foam and overall performance of the product.

Treat a surfactant substitution as a reformulation, not a simple ingredient swap.

For a practical example of a surfactant-based solid product, see my Rosemary Shampoo Bar or cheeck my Shower oil.

Shop Surfactants

Once you know the type of cleanser you want to formulate, look for surfactants according to their function, active matter and supplier specifications, rather than choosing them by marketing description alone.

US: Browse on Amazon
Europe: Browse at Mireille Lab

Humectants

Humectants are water-binding ingredients used in skincare formulations to help increase and maintain hydration. They are commonly found in water-based products such as serums, gels, lotions and creams.

Some of the most familiar humectants include glycerin and hyaluronic acid, while ingredients such as aloe vera and red algae gel can contribute polysaccharides and other water-soluble components to hydrating formulations.

But adding a humectant is not simply about making a product “more hydrating.” Different ingredients can also influence viscosity, tackiness, slip and overall skin feel, so the right choice depends on what you want the finished product to do.

How Do You Choose a Humectant?

Start with the type of product you are making and the sensory profile you want to achieve.

Glycerin is versatile, widely available and easy to incorporate into many water-based formulations, but higher amounts can create a noticeably tacky feel. Hyaluronic acid has very different formulation characteristics and is available in different molecular weights and forms.

Aloe vera and red algae gel are different again. They are complex ingredients rather than single humectant molecules, so they should not automatically be treated as direct substitutes for glycerin or hyaluronic acid.

Always check the supplier’s recommended usage rate, ingredient form, solubility and any specific formulation requirements before deciding how much to use.

Do You Need More Than One Humectant?

Not necessarily.

It can be tempting to combine several ingredients simply because they are all associated with hydration, but more humectants do not automatically make a better formula.

Instead, consider what each ingredient contributes. You might use glycerin as a straightforward humectant and add aloe vera or red algae gel because you also want their particular formulation or sensory characteristics. The goal is to build a formula in which each ingredient has a reason to be there.

If you’re starting with one of the most versatile options, my Glycerin guide takes a closer look at how glycerin works and how it can be used in DIY skincare formulations.

Shop Humectants

You don’t need a large collection of humectants to formulate effectively. Glycerin is a versatile starting point for many water-based products, while ingredients such as hyaluronic acid, aloe vera or red algae gel can be added when you want different hydration, texture or sensory characteristics.

When comparing products, pay attention to the actual format you are buying. Hyaluronic acid may be sold as a powder or pre-hydrated solution, aloe vera in different concentrations, and algae ingredients as powders, extracts or ready-to-use gels — so products with similar names are not necessarily interchangeable.

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Europe: Browse at Mireille Lab

Emulsifiers

Emulsifiers make it possible to combine oil and water into a stable emulsion. Because these two phases naturally separate, an appropriate emulsifier or emulsifying system is needed to keep one phase dispersed within the other.

This gives us two main types of cosmetic emulsions:

• Oil-in-water (O/W) – small droplets of oil are dispersed throughout a continuous water phase. This type of emulsion is widely used for lotions, facial moisturizers and lighter creams.
• Water-in-oil (W/O) – small droplets of water are dispersed throughout a continuous oil phase. These emulsions generally create richer, more water-resistant products with a different skin feel.

Cosmetic emulsions consist of two immiscible liquid phases, with one dispersed as droplets within the other. The two most common types are oil-in-water (O/W) and water-in-oil (W/O) emulsions (Akanny et al., 2024).

Common emulsifiers you may encounter in DIY skincare include Olivem 1000, BTMS-50 and Montanov emulsifiers, but they are not interchangeable simply because they all help create emulsions.

How Do You Choose an Emulsifier?

Start with the type of emulsion you want to create.

If you are making an O/W emulsion, you need an emulsifying system designed to stabilize oil droplets within a continuous water phase. A W/O formulation requires a system suitable for the opposite arrangement.

The amount and type of oil phase also matter. An emulsifier that performs well in a light facial lotion may not be the best choice for a formula containing a much larger oil phase or for a richer cream.

Emulsifier choice can also noticeably change the finished product. Two emulsifying systems can produce stable emulsions while creating very different viscosity, spreadability, absorption and after-feel.

Can You Substitute One Emulsifier for Another?

Not necessarily.

Switching emulsifiers can change more than the texture of your cream. Different emulsifying systems have their own requirements and may support different oil-phase percentages, processing methods and types of emulsion.

Replacing one emulsifier gram-for-gram with another should therefore be treated as a reformulation rather than a direct substitution.

Shop Emulsifiers

Before choosing an emulsifier, first decide whether you are formulating an O/W or W/O emulsion and consider the type of texture you want to create. This immediately narrows the range of emulsifiers that make sense for your formula.

US: Browse on Amazon
Europe: Browse at Mireille Lab

Solubilizers

Solubilizers help incorporate small amounts of oil-soluble ingredients into water-based formulations. They are especially useful for ingredients such as essential oils and fragrance materials that would otherwise separate and float on the surface.

Unlike emulsifiers used to create creams and lotions from larger oil and water phases, solubilizers are typically used when the formulation is mostly water with only a small amount of oil-soluble material.

Two options you may encounter in natural skincare formulation are:

• Solubol – a natural, vegan solubilizer commonly used to disperse essential oils in water-based products.
• Symbio®solv Clear – a PEG-free solubilizing system suitable for formulations where a clear or transparent appearance is desired.

What Is the Difference Between a Solubilizer and an Emulsifier?

Both help deal with ingredients that do not naturally mix with water, but they solve different formulation problems.

An emulsifier creates and stabilizes an emulsion containing an oil phase and a water phase, such as a lotion or cream. A solubilizer, on the other hand, helps disperse a relatively small amount of an oil-soluble ingredient within a predominantly water-based formulation.

This makes solubilizers particularly useful in products such as facial mists, toners and sprays, where you do not want a separate layer of oil sitting on top of the product.

How Much Solubilizer Do You Need?

There is no universal solubilizer-to-oil ratio.

The amount required depends on the specific solubilizer and the oil-soluble ingredient you are trying to incorporate. Even two essential oils may require different amounts of the same solubilizer to produce an acceptable result.

For this reason, test the combination on a small scale and follow the technical guidance for the specific solubilizer you are using rather than assuming that one ratio will work for every formula.

Shop Solubilizers

Choose a solubilizer according to what you need to incorporate and the type of finished product you want to create. If clarity matters, for example, look for a solubilizing system designed to produce clear or nearly clear water-based formulations.

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Europe: Browse at Mireille Lab

Thickeners & Gums

Thickeners and gums help control the viscosity, texture and flow of a skincare formulation. They can turn a thin liquid into a gel, give a serum more body or help create the consistency you want in a finished product.

Common examples include xanthan gum, guar gum and konjac gum, although different gums can create noticeably different textures even when they perform a similar general function.

Why Does the Choice of Gum Matter?

Choosing a gum is not simply about making a product thicker.

Different gums can affect flow, spreadability, skin feel and the appearance of the formulation. Some create smooth, flowing gels, while others produce thicker or more elastic textures. The final result also depends on how much is used and how the gum behaves with the other ingredients in the formula.

Gums also need to be properly dispersed and hydrated. Poor dispersion can lead to clumps and uneven texture, which is why the way a thickener is incorporated can be just as important as the amount used.

For now, think of gums as formulation tools for controlling texture and consistency, rather than ingredients added simply to make a product “thicker.”

Research on cosmetic emulsions shows that different polysaccharide thickeners can produce different rheological properties, influencing how a formulation flows and behaves during use (Vianna-Filho et al., 2013).

Ingredients for Formula Stability & Safety

Creating a skincare formula is not only about choosing ingredients for texture, skin feel or performance. You also need to consider what happens to the product during storage and use.

Some ingredients help protect a formulation from microbial growth, oxidation or changes that can affect its stability over time. This is where preservatives, antioxidants and other stability-supporting ingredients become important.

Preservatives

Preservatives like Geogard 221 help protect cosmetic formulations from microbial contamination and growth during storage and use. They are particularly important in products that contain water, such as creams, lotions, gels, toners and water-based serums.

A preservative is not chosen simply because it is described as “natural” or “broad-spectrum.” Different preservation systems work under different conditions, and their effectiveness can depend on factors such as pH, formulation composition and the microorganisms they are designed to control.

When Does a Formula Need a Preservative?

If a formulation contains water — including water introduced through ingredients such as hydrosols, aloe-based ingredients or botanical infusions — microbial safety needs to be considered from the beginning of the formulation process.

Anhydrous products present a different preservation challenge. A product containing only oils and waxes does not automatically require the same preservation system as a water-based emulsion, although the way the product is packaged and used can still introduce contamination risks.

Can You Replace One Preservative with Another?

Not automatically.

Preservatives have different effective pH ranges, recommended concentrations and compatibility requirements, so replacing one preservative with another can require changes to the formulation.

Preservation should therefore be treated as part of the formulation system, rather than as an ingredient added at the end simply to extend shelf life.

A common DIY misconception is that storing a water-based cosmetic in the refrigerator removes the need for an appropriate preservation strategy. Refrigeration should not be treated as a substitute for properly formulated microbial protection.

Cosmetics containing available water can support microbial contamination, which is why preservation needs to be considered as part of the formulation rather than simply as a way to extend shelf life (Halla et al., 2018).

Antioxidants

Antioxidants help protect oxidation-sensitive ingredients in a formulation, particularly plant oils, butters and other lipid-based materials. Oxidation can gradually change the smell, colour and quality of these ingredients and eventually lead to rancidity.

One of the most familiar antioxidants in DIY skincare is tocopherol (vitamin E). Research on lipid-based systems shows that tocopherols can help slow lipid oxidation, although their effectiveness depends on the composition and characteristics of the formulation (Barouh et al., 2022).

Are Antioxidants the Same as Preservatives?

No — and this distinction is important.

Antioxidants help slow oxidation, while preservatives are used to control microbial contamination and growth. Adding vitamin E to a water-containing formulation therefore does not replace the need for an appropriate preservation strategy.

Antioxidants can be particularly useful in anhydrous products such as facial oils, balms and body butters, where oxidation of the oil phase may be one of the main factors affecting product quality over time.

The stability of a formulation also depends on the oils being used. Some botanical oils are naturally more susceptible to oxidation than others because of differences in their fatty-acid composition.

For a deeper look at this relationship, see my Botanical Oil Guide, where I explain how fatty-acid composition and iodine value can help you understand the relative oxidation susceptibility of botanical oils.

Chelating Agents

Chelating agents help improve formulation stability by binding metal ions that may enter a cosmetic product through water, raw materials or processing.

Even small amounts of metal ions can contribute to unwanted changes in a formulation. By binding these ions, chelators can reduce their availability to participate in reactions that may affect the product over time.

Common cosmetic chelators include EDTA and its salts, sodium phytate and GLDA (Tetrasodium Glutamate Diacetate). Sodium phytate, for example, is specifically identified as a chelating agent used in cosmetic formulations in a recent Cosmetic Ingredient Review safety assessment (CIR Expert Panel, 2024).

Why Are Chelating Agents Useful in a Formula?

Chelators can work alongside other parts of the stability system, including antioxidants and preservatives.

Research on cosmetic preservation shows that chelating agents can support preservation systems by binding metal ions and, in some cases, increasing the susceptibility of microorganisms to antimicrobial agents (Halla et al., 2018).

This does not make a chelating agent a replacement for a preservative or antioxidant. Instead, think of it as another tool that can help the overall stability system work more effectively.

Advanced & Special Ingredients

Once you understand the ingredients that build, stabilize and protect a formulation, you can start working with more specialized ingredients to refine its performance, appearance and sensory profile.

This group includes cosmetic actives selected for specific functions, botanical extracts, functional powders and concentrated aromatic ingredients. Unlike many basic formulation ingredients, these materials often require closer attention to concentration, solubility, compatibility and the way they are incorporated into a formula.

Active Ingredients – Targeted Boosters

Active ingredients, often called cosmetic actives, are selected to provide a specific function within a skincare product. Their activity is often associated with a defined compound or molecular group, allowing formulators to work with more controlled concentrations and formulation parameters.

Common categories include:

• Hydration and barrier support: hyaluronic acid, panthenol and beta-glucan
• Brightening and uneven tone: niacinamide and vitamin C derivatives
• Age-supporting formulations: peptides, coenzyme Q10 and bakuchiol
• Exfoliation and renewal: AHAs, salicylic acid (BHA) and PHAs
• Soothing formulations: allantoin and bisabolol

Why Can’t You Simply Add an Active to Any Formula?

An active needs to work within the formulation that carries it.

Depending on the ingredient, you may need to consider its solubility, pH range, temperature sensitivity, concentration and compatibility with other ingredients. Adding more is not automatically better, and an effective concentration for one active cannot simply be applied to another.

Research on skincare delivery systems also shows that cosmetic actives can be sensitive to factors such as light, oxygen, pH and temperature, making the formulation itself important for maintaining their stability and performance (Kouassi et al., 2022).

If you want to investigate an unfamiliar active before adding it to a formula, my Skincare Ingredient Dictionary explains how to research ingredient identity, function, compatibility and safety using reliable cosmetic databases.

Active Botanicals

Active botanicals bring plant-derived materials into skincare in forms that can be incorporated into a cosmetic formulation. Depending on how the plant material has been processed, these may include glycerites, hydroglyceric extracts, oil-soluble extracts, CO₂ extracts and other botanical preparations.

The important point is that the name of the plant alone does not tell you how an extract will behave in a formula.

Why Does the Type of Botanical Extract Matter?

Extraction changes what reaches the finished ingredient.

The solvent and extraction method determine which groups of plant compounds are extracted and also influence whether the resulting ingredient is suitable for the water phase, oil phase or another part of the formulation.

This means that a glycerin-based extract, an infused oil and a CO₂ extract from the same plant are not interchangeable simply because they come from the same botanical source.

If you want to make your own botanical extracts, you can start with a simple herbal oil infusion or learn how to make a glycerite. For a comparison of different extraction approaches and what they produce, see my Herbal Extracts Guide.

You can also explore individual plants, extraction methods and botanical ingredients in my Botanical Library.

Colors & Functional Powders – Texture, Appearance & Sensory Feel

Powders can do much more than add color to a cosmetic product. Depending on the material, they can help absorb excess oil, reduce greasiness, improve slip, modify texture or create visual effects.

Examples include arrowroot and rice starch for absorbency and a softer finish, while mineral pigments and micas can provide color, opacity or shimmer.

The important distinction is between a powder added mainly for appearance and one added for a functional formulation purpose. Two powders that look similar may behave very differently when incorporated into a formulation.

Research on cosmetic powders shows that the choice of powder can significantly influence the sensory characteristics of an emulsion, including its behavior during application and after-feel (Moussour et al., 2017).

For a practical example of how mineral shimmer behaves in an anhydrous formulation, see my DIY Shimmering Dry Oil, where I compare mica and other shimmer systems and show how they behave in an oil-based formula.

Aromaceuticals – Essential Oils & Aromatic Extracts

Aromaceuticals are concentrated aromatic materials used in cosmetic formulations primarily for their aroma and sensory contribution. Unlike fixed botanical oils, essential oils contain volatile compounds and are generally used at much lower concentrations.

This group can include essential oils, selected aromatic CO₂ extracts and absolutes, depending on the formulation and the material being used.

Why Does Dosage Matter?

Essential oils should not be treated simply as natural fragrance added “to taste.”

Their chemical composition varies considerably, and some constituents can present dermal sensitization, irritation or phototoxicity concerns. The appropriate concentration therefore depends on the specific aromatic material, the finished product and how that product will be used.

For example, some essential oils and botanical extracts contain furocoumarins, compounds associated with phototoxic reactions following exposure to UVA light. This is particularly relevant to certain expressed citrus oils (Irizar et al., 2025).

Fragrance safety assessment also considers the type of finished product and expected dermal exposure when establishing acceptable use levels for fragrance materials associated with sensitization (Api et al., 2008).

For this reason, essential-oil safety should be considered as part of the formulation itself, rather than after the fragrance has been chosen.

For a practical example, see my Shower Oil, where fragrance or essential oils are considered as part of a complete anhydrous rinse-off formulation.

From Skin Goal to Ingredient Choice

Knowing what an ingredient does in a formula is only part of the decision. You also need to consider what you want the finished product to achieve.

For example, a formula designed for dry skin might combine humectants to support hydration with emollients that improve softness and reduce moisture loss. A lightweight formula for oilier skin may use the same ingredient families but rely on different emollients, textures and proportions.

The important point is that a skin goal does not usually point to one “best” ingredient. It helps you decide which ingredient functions you need and how they should work together in the finished formula.

If you are ready to see how these choices come together in complete formulations, continue to my DIY Skincare Recipes or browse the DIY Skincare Recipe Library.

Beyond the Basics

Once you understand the main DIY skincare ingredient groups and what they contribute to a formula, the next step is learning how to work with them in practice. Skills such as ingredient substitution, troubleshooting and formula adjustment can help you make more informed formulation decisions instead of simply following a recipe.

Decoding INCI Names

Every cosmetic ingredient has an INCI (International Nomenclature Cosmetic Ingredient) name, which provides a standardized way to identify ingredients across cosmetic products and supplier documentation.

Learning to recognize INCI names makes it easier to compare ingredients, read supplier specifications and understand what you are actually adding to a formula. This becomes particularly useful when trade names differ between suppliers or when a commercial ingredient contains more than one component. Learn mor on INCI Decoder

You can look up individual ingredients and learn how to research their function, compatibility and formulation role in my Skincare Ingredient Dictionary.

Ingredient Substitutions

Ingredient substitution is not simply about finding another ingredient with a similar name or texture. A suitable substitute needs to perform the same function in the formula while also fitting the formulation system.

Replacing one botanical oil with another may change the sensory profile and oxidation stability. Changing an emulsifier, surfactant or preservative can have a much greater effect because it may alter the structure, pH requirements or stability of the entire formulation.

Before making a substitution, ask: What is this ingredient doing in the formula, and what will change if I replace it?

That question is often more useful than asking whether two ingredients are direct substitutes.

Storage Essentials

How you store cosmetic ingredients can affect their quality long before they reach your formula. Light, heat, oxygen and moisture can accelerate changes in certain raw materials, while different ingredient groups have different storage requirements.

Botanical oils, antioxidants, preservatives, powders and water-based materials should therefore not automatically be stored in the same way.

For practical guidance on organising and protecting your raw materials, see How to Store Cosmetic Ingredients.

FAQ – Frequently Asked Questions

From Ingredients to Formulation

Understanding ingredients changes the way you approach DIY skincare.

Instead of asking only “Which ingredients should I use?”, you can begin asking more useful formulation questions: What function does this ingredient perform? Is it compatible with the rest of my formula? How much should I use? What does the finished product need to remain stable and safe?

That is the difference between simply mixing ingredients and beginning to understand how a formula works.

Use this guide as your reference for ingredient families and formulation roles. When you are ready to put that knowledge into practice, continue to my DIY Skincare Recipes to learn how ingredients work together in complete formulations, or browse the DIY Skincare Recipe Library for individual formulas.

And if you want to take a wider look at how ingredient sourcing, formulation choices, packaging and waste connect, continue to Sustainable Beauty Practices.

The goal is not to use more ingredients. It is to understand why each ingredient is there and what it contributes to the formula.

Kristina