There are numerous amounts of cosmetic ingredients that are used. As an introduction, I’ll be going over some popular cosmetic ingredients — based on a simple Google search “popular cosmetic ingredients”. A lot of the information below is information that I’ve gathered through experience, but please feel free to browse the links at the end of the post! Happy reading & happy formulating!
Parabens are based on parahydroxybenzoic acid — see the structure above. The R group is what determines what the paraben is, ex: methylparaben, ethylparaben. They show strong antimicrobial properties & have been used in many products & industries (cosmetic, pharmaceutical, food, & industrial) as preservatives.
Parabens are effective against Gram+ and Gram- bacteria, yeast, and mold at relatively low concentrations. They’re cheap and compatible with many types of products.
There have been some concerns about how parabens affect people’s health or how it can cause cancer. Parabens have been studied extensively for decades now and have been deemed safe for us (within a particular percentage, of course). The CIR’s new draft on the report of parabens in cosmetics have suggested that they are safe for use, but their final decision will occur in April 2019.
In my opinion, you should not be concerned about using products that contain parabens (so long as they are being used at proper levels). See chart below for recommended use levels.
“Paraben-free” is a marketing ploy developed from the paraben-scare that parabens were linked to cancer. Studies have shown its safety and unless you’re actually allergic to parabens, I think you’ll be fine to use parabens.
I would be more concerned about using products that do not have any preservatives in it rather than having parabens.
One of my favorite products that just so happen to contain parabens:
- CeraVe Moisturizing Cream for Normal to Dry Skin ($13.99 for a 12 oz)
Formaldehyde is the simplest of the aldehydes and is found in plants, animals, and humans. We produce formaldehyde as a part of our metabolism, and when inhaled, it is metabolized and converted to carbon dioxide when we exhale. It is a by-product from combustion processes — fires, automotive exhausts, cooking, cigarette smoke.
High exposure to formaldehyde has been known to possibly cause irritation or cancer.
Formaldehyde and formaldehyde-releasing ingredients are used as preservatives. They are typically used in very small amounts, which can be considered safe (considering how often people are exposed to formaldehyde in other forms).
The CIR evaluated the scientific data and concluded that formaldehyde in cosmetics is safe at established levels and concentrations.
Hyaluronic acid is a polysaccharide that is naturally occurring in our bodies and our skin. Due to its polar nature, it can hold onto water efficiently. Hyaluronic Acid is extremely hygroscopic, tendency to absorb moisture from the air, and can bind up to 1000x its weight in water — hydration power at its finest!
Hyaluronic acid in your skin decreases with age and may contribute to the development of fine lines, wrinkles, and other signs of aging. Some fillers used in dermatology or plastic surgery uses hyaluronic acid solution injections.
In cosmetics, Hyaluronic Acid can be offered in different sizes — high and low molecular weights. High molecular weight hyaluronic acid moisturizes skin and forms viscous solutions. Low molecular weight hyaluronic acid can increase skin elasticity and reduce fine lines and wrinkles — it’s believed to have better skin penetration because its lower in molecular weight.
You may sometimes see Sodium Hyaluronate in place of hyaluronic acid (see structure above for differences).
Sodium hyaluronate is the sodium salt form of hyaluronic acid & typically has a lower molecular weight. Again, it is thought to have better skin penetration because of its lower molecular weight with the same moisturizing and water binding capabilities.
My favorite Hyaluronic Acid / Sodium Hyaluronate containing products:
- The Ordinary Hyaluronic Acid 2% + B5 ($6.80 for 30 mL) – You really can’t the price on this one!
- COSRX Hyaluronic Acid Intensive Cream ($21.00 for 3.38 oz)
- The Plant Base Waterfall Moist Balanced Hyaluronic Acid 100 ($23.00 for 20 mL)
- Glow Recipe Watermelon Pink Juice Moisturizer ($39.00 for 2 oz)
Retinol is Vitamin A and has been used in skincare to target many concerns, such as: pigmentation, wrinkles, aging, and more. The major dietary sources of retinoids are plant carotenoids (e.g. carrots) and retinol esters derived from animal derived foods. Retinol is a storage form of vitamin A that can be converted to retinal which is important for eye health — this is why people say that carrots are good for your eyes (but we also see that it is good for our skin).
There are many forms of vitamin A used in the market — retinol, retinyl palmitate, hydroxypinacoloneretinoate, retinyl retinoate, retinal, etc. These different forms of vitamin A have various claims in irritation, photo and heat stability, and efficacy.
It is important to use SPF when you are using a product with retinol or vitamin A because of light sensitivity. Retinol products should generally be used at night to prevent further irritation from the sun.
My favorite retinoid-containing product:
- The Ordinary Granactive Retinoids 2% in Squalane ($9.60 for 30 mL) – The Ordinary offers Retinol in Squalane & also offers it in a stronger dose (%). I specifically like the one that I listed above because I do not experience dry, flaky skin with use.
Titanium dioxide is typically used in sunscreens, makeup, & cosmetics. It can act as a UVB absorber, a physical sunscreen. It works by sitting on top of the skin and deflecting or scattering UV rays from the skin.
You will see titanium dioxide on the California Prop 65 list, but the main thing to point out is that it lists AIRBORNE, UNBOUND particles of respirable sized titanium dioxide. When in an emulsion, titanium dioxide is thus, bound and almost impossible to be breathed in.
Zinc oxide is another physical sunscreen and acts as a UVA absorber. In combination with titanium dioxide, you’ll then have protection against UVA & UVB rays. However, it may be necessary to use SPF boosters when formulating with either metal oxide to boost efficacy.
Metal oxides used as physical sunscreens may leave a white cast during use & so formulating with them may be a little more difficult if you wish to give better aesthetics to your product.
Nonetheless, titanium and zinc oxide are great physical sunscreens & it is important for you to use SPF everyday & reapply regularly! I highly recommend to use a sunscreen of at least SPF 30!
If a product makes any SPF-claims, you will be able to see the “Active Ingredients” on the label, & you will also see at what % of the ingredient is used.
Sodium Laureth Sulfate
Sodium laureth sulfate (SLES) is an an ionic surfactant that is used in numerous cleansing products such as shampoos, liquid soaps, body washes, etc. It has excellent foaming and cleaning properties.
Sulfates in general are fairly cheap surfactants that foam well & are easy to formulate with. When formulating with non-sulfate surfactants, there may come the challenge of needing to boost the foam or needing to thicken the product. They are also generally more expensive to make since you may have to add extra ingredients to boost foam and add thickness — probably not by much, but everyone has a budget that they’re working with.
I personally prefer cleansing products that are sulfate-free because they are more mild and less irritating, but I’ve also never had any major issues when using sulfate-surfactants either. Therefore, to each their own!
Vitamin E is an excellent anti-oxidant and anti-inflammatory ingredient. It is oil-soluble and stops the product of ROS formed when fat undergoes ovation — it protects cells from the damaging effects of free radicals.
Most forms of vitamin E that you will see on ingredients lists will be: tocopherol acetate or tocopherol.
I like to add vitamin E to oil-based (anhydrous) products to help prevent the product from oxidizing & becoming rancid as quickly.
Alpha hydroxy acids are known as AHAs and are extremely popular cosmetic ingredients used for chemical exfoliation. They can improve your skin’s texture and tone & have been used to treat and aid conditions like sun damage, acne, spots, and wrinkling.
Chemical peels used by dermatologists or professionals typically use AHAs — it is a technique that improves and smooths the texture of your skin. This is probably another reason why AHAs in cosmetics are so popular.
You will not see “AHA” listed on the ingredients list. Instead, you will see ingredients like: glycolic acid, lactic acid, mandelic acid, or the INCI names of fruit acids that naturally contain AHAs.
My favorite AHA-containing products:
- The Ordinary AHA 30% + BHA 2% Peeling Solution ($7.20 for 30 mL) – The Ordinary has a wide range of AHAs in their line. I just happen to really like this because of how well it works at such a great price point. I use this once a month on my t-zone to clear pore congestion.
- Peach & Lily Super Reboot Resurfacing Mask ($43 for 80 mL)
Allantoin is used to help minimize the appearance of aging and skin damage. It has wound healing properties & has great moisturizing, soothing, and anti-irritant properties. It is provided as a white-powder & has great water solubility. It can be found in plants like comfrey and horse chestnut.
A popular ingredient in the food industry, now also popular in the cosmetic industry. Avocados 🥑 are trendy & make for a great marketing story.
Avocado oil is used as an emollient in cosmetics & has rapid skin absorption. It is great as a moisturizer & is rich in vitamins and essential fatty acids.
All the more reason to love avocados & avocado oil!
An Avocado-oil containing product:
- Glow Recipe Avocado Melt Sleeping Mask ($45 for 80 mL) – Please refer to my previous post to see my Science-based review on this product.
It really depends on the person whether or not they like beeswax, and it all comes down to vegan or non-vegan product usage.
Beeswax can be used to stabilize different products — emulsions, lipsticks, balms, etc. — and has occlusive properties that will prevent transepidermal water loss.
As a formulator, I like to use beeswax because its simple & “natural”. It works! I do try my best to curate towards pro-vegans & will use other waxes like ozokerite or microcrystalline.
A fancy word for “dimethicone”, which is what you’ll typically see on ingredients lists. I am a silicone-lover & love to formulate with silicones & elastomers because of the neat textures that can be created with them.
Dimethicone is a silicone oil that applies silky-smooth. It fills in fine lines and skin textures, it adds slip to formulas, and prevents moisture loss. Dimethicone is offered in various viscosities, from low to high. I just happen to really like how Dimethicone 100 cst feels.
I’ve heard some people say that dimethicone forms a plastic layer, and those people may be thinking about the form-filming ability of the ingredient (and making it an extreme thing to scare people — lame, by the way). Dimethicone forms a PERMEABLE layer wherever it is that you put it on you. If you have it in your hair product & put it on your hair, it’s not going to be something that suffocates your hair or anything like that. If it wasn’t permeable, you wouldn’t be able to dry your hair. Furthermore, the film that is formed aids as an occlusive & helps prevent moisture loss.
I like to use dimethicone in lotions/creams, hair conditioners, and makeup products like primers to add an aesthetic feel to them. In hair conditioners, since dimethicone adds “slip” to products, it really helps in combability and detangling. Dimethicone is awesome!
References / Additional Reading:
- Scientific Committee on Consumer Products – Safety Evaluation of Parabens
- American Chemistry Council – Formaldehyde
- California Prop 65 – Titanium Dioxide Warning
- Long-term Repetitive Sodium Lauryl Sulfate-Induced Irritation
- National Institute of Health – Vitamin E
- Lush Cosmetics – Beeswax
- Vogue: Skincare Alphabet – D is for Dimethicone