What’s in my skincare product? Cosmetic INCI ingredient lists explained for the consumer.
David L Stachura and Kristen Rueb
A common question many consumers have is: “how much of ______ chemical is in my skincare product?” I also hear “what is ______, anyway?” And, “is ______ safe?” The amount and identity of chemicals used in skincare is easily assessed, and you don’t need to be an organic chemist to figure out what is in a cosmetic product that you may use. The safety issue is a bit tricky, but read on.
Cosmetic products versus drug products
First, we need to define what a cosmetic product is, and how they are regulated in the United States. A cosmetic product is defined by the US Food and Drug Administration (FDA) as something “intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body…for cleansing, beautifying, promoting attractiveness, or altering the appearance” (FD&C Act, sec. 201(i)). In essence, it is to clean you and make you look better temporarily. Makeup, perfume, lipstick, skin moisturizers, skin cream, hair color, etc. fall into this category.
So, what exactly is a drug? Well, the FDA defines drug products as “articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease” and “articles (other than food) intended to affect the structure or any function of the body of man or other animals” (FD&C Act, sec. 201(g)(1)). In other words, a drug is intended to alter the body’s physiology and fix a problem. Most of us could easily think of a bunch of well-known drug products that we use regularly, whether they are prescribed by a doctor or over-the-counter (OTC).
It gets a little tricky when we start to think about things that are classified as cosmetics and drugs. A great example would be anti-perspirant. While deodorant is a “cosmetic” (it just makes you smell better), an anti-perspirant is a drug (because it alters the physiological process of sweating). Another example? Anti-dandruff shampoo; it both cleans your hair (its cosmetic use), but also treats a medical condition (dandruff). Sunscreen is another good example, as it moisturizes your skin, but also has a sun-protective quality that protects the skin from UV radiation. All of these products are regulated by the laws that govern cosmetics and drug products.
In general, cosmetic products can’t really make “claims” as to what they do, because they aren’t supposed to alter the body or treat a medical condition. Cosmetics can “reduce the appearance” of wrinkles. But if they “treat” wrinkles? Then they are classified as a drug.
Who regulates all of this?
In essence, the FDA regulates drugs (obviously this is only in the United States, although lots of countries follow the rules and regulations set forth by the FDA). Drugs need to go through an approval process before they go on the market. Briefly, drugs need to go through a new drug application (NDA) process or conform to a pre-existing monograph to be approved as an OTC drug. Let’s say you’re a company that wants to sell a drug to treat cancer or hypertension. You would need to file an NDA, show the FDA relevant tests and data, and then they would approve your drug for sale on the market. In other words, you’d have to prove that the drug did what you said it would and that it was safe. If you want to sell an OTC drug, you could use an approved monograph. The FDA basically has a list of pre-approved chemicals that are safe and effective for specific purposes. If you follow the monograph (really just a rule book of what chemicals you can use and how you can use them), you can sell an OTC without it being tested by the FDA. For example, if you wanted to sell a sunscreen (remember- this is an OTC drug), you simply need to follow the FDA monograph for that product, which tells you what chemicals would work, what percentage they need to be, and what tests you need to follow to make sure you’re in compliance with their rules. If your OTC drug doesn’t conform to a monograph, then it needs to go through the NDA process (if you want to sell a sunscreen with a chemical that the FDA hasn’t approved yet but you believe blocks UV rays in a similar manner). In other words- if it’s a drug? It’s regulated by the FDA.
But who regulates cosmetics? Cosmetics live in a strange regulatory space. In general, the FDA cares most about preventing the adulteration or mislabeling of cosmetics. In other words, the FDA gets involved if someone is making unfounded claims about a cosmetic product or if that product is mislabeled or dangerous. Only recently has the United States come up with rules for cosmetics called the Modernization of Cosmetics Regulation Act of 2022 (MoCRA) that now requires producers to use good manufacturing practice (GMP) requirements in their facilities. This law is the most significant expansion of FDA’s authority to regulate cosmetics since the 1930’s, and makes sure that companies are licensed and approved before they can make cosmetics. It’s a way to make cosmetic companies more responsible for the products they produce. While MoCRA gives the FDA more “teeth” to enforce rules that govern cosmetics, it is not the same type of requirement that the FDA has for bona fide drugs; those rules and regulations are much stricter.
How do I know what is in my cosmetic product?
The good news for consumers is that MoCRA is instituting rules and regulations on the labeling of cosmetic products here in the United States. So, the FDA will be regulating cosmetics, at least on some level. However, most responsible cosmetic companies have already been labeling their product ingredients by listing them out in what is known as the International Nomenclature Cosmetic Ingredient list (INCI). INCI is a uniform labeling system, established in the 1970’s, of listing names for cosmetic ingredients that consumers, producers, and regulators can understand.
Why do we need this type of labeling system? In essence, it’s so that everyone knows what is in a particular product and when you pick up a cosmetic product and read the list of ingredients you can easily tell what is in it. And, fun fact? It also gives you the relative abundance of that ingredient in the mix (not the exact concentration- those are usually trade secrets 🙂).
So, now that you know there is a uniform listing system, let’s discuss how to read the list and determine what is in your cosmetic product.
The first thing to do is locate the list. Due to MoCRA regulations, this needs to be on the product and has to be prominently marked. Lot’s of companies list the INCI on their website, as well. Let’s use a FACTORFIVE Skincare product (Gentle Gel Cleanser) as an example.
The INCI is on the box, and lists the following ingredients:
Here’s the important part- the chemicals are listed in the order of concentration, from highest to lowest. Convenient, right? So, in our example, we have water as the number one ingredient (that’s common in most water-based cosmetic creams and cleansers). And, you guessed it, Disodium EDTA (a chelating agent) is the least concentrated chemical in this product. There is a caveat: this is how the system should work- some companies simply list ingredients in alphabetical order, which is definitely not the way the list should be compiled on the package. If it’s in alphabetical order, then don’t use the list to gauge the amount.
But what are these chemicals? Some will look familiar to most people, like water. Skincare aficionados might recognize tocopherol (the chemical name of Vitamin E, an antioxidant) and sodium hyaluronate (the sodium form of hyaluronic acid that is a critical component of the skins’ extracellular matrix). But the other chemicals are likely a little esoteric to most consumers.
How can you figure it out? Well, there are lots of great websites like INCI decoder that have a useful searchable format- just put in the chemical name and click on “ingredients,” and the website will show you the chemical structure (and/or chemical nomenclature), give you the official INCI name, and a little information on the ingredient’s function. It will also give you its chemical abstracts services (CAS) number. If you want to go deep into a chemical’s information, this number is key.
Let’s use cocamidopropyl hydroxysultaine as an example; this is probably not a common chemical to most consumers. If you search for that, you’ll find the function of the chemical to be: “antistatic, cleansing, foam boosting, hair conditioning, skin conditioning, surfactant, (and) viscosity controlling.” In plain language: it’s the “soap” part of the cleanser (that’s what a “surfactant” is). If you don’t know the function terms, just do a Google search. Conveniently, this entry has a description describing this as “mild,” “gentle,” biodegradable,” and made from coconuts. So, it’s a soap made from coconuts. Pretty easy.
The system isn’t perfect, though. Some things actually have the same INCI, but are slightly different compounds. One great example of this would be “green tea,” which is an antioxidant added to many skincare products. The INCI listing for this ingredient is “Camellia Sinensis Leaf Extract” because it is extracted from the Camellia sinensis tea plant. But, all true teas (white, yellow, green, oolong, and black tea) are made from this plant. To indicate the difference, most products, like the one shown above, denote this by placing terms in parentheses. Basically, it’s trying to help the consumer decipher the “common” name of the chemical. The difference between these tea extracts is simply their oxidation state- white tea is the least oxidized, and black tea is the most. They have different roles and effects in skincare products.
If you’re approaching this as someone that formulates skincare, the INCI listing can also be a little problematic. A great example would be the INCI listing “sodium polyacrylate,” which is a common thickener. However, you can have very different versions of the same chemical (with the same INCI name). One is linear sodium polyacrylate (really just a string of the chemical repeated over and over), which is stringy and good for making more liquid-like products. Additionally, you can get cross-linked sodium polyacrylate (so the chemical is linked together with others in a non-linear way), which creates a richer, thicker gel. Think about it like a piece of yarn laid out in a straight line (linear version) versus taking that string, balling it up, and gluing it together in a clump (the crosslinked version). The result for a skincare product would be something that is runny (like a serum) versus something that is firmer and gel-like that is more solid and firm. You get a very different feel from the product with these different chemicals. But, their INCI is the same.
If it’s on an INCI list, is it safe?
This is the question that everyone wants to know, and it is tricky. The important thing you should know as a consumer: the presence of a chemical on the INCI list doesn’t necessarily mean it is safe or approved for use in cosmetics. The onus for showing safety and efficacy for a product lies on the manufacturer. Remember, the FDA doesn’t currently regulate cosmetics- they only regulate if the cosmetic is adulterated or is making specific claims that cannot be substantiated. However, the FDA has already banned some specific dangerous substances such as mercury compounds and chloroform. The recent MoCRA law will also allow the FDA to investigate ingredients like per- and poly-fluoroalkyl substances (PFAS) and their safety in cosmetics as well as establishing and requiring standardized testing methods for detecting and identifying asbestos in talc-containing cosmetic products. Importantly, cosmetics may contain a wide range of fragrances, which are natural or synthetic compounds added to impart a characteristic and pleasant smell. The problem is, certain fragrances may also cause allergic reactions. So, MoCRA will institute that each fragrance allergen included in the product must be identified on the label. MoCRA will also require cosmetic manufacturers to have a system in place to record and deal with adverse reactions and report these issues to the FDA. Additionally, the FDA will have the ability to go through records for the products and order mandatory recalls, if necessary. Interestingly, while the FDA won’t tell a manufacturer how to do safety testing of their product, they are demanding that the product be safety tested on some level. Certainly those regulations will evolve over time, especially since many of these regulations are reactive, versus proactive. In conclusion? The manufacturer of a cosmetic product is responsible for its safety; the FDA doesn’t regulate cosmetic products or ingredients for safety at this time.
So, how do I investigate if a chemical in the INCI list is safe?
This is tough, because you need to do some sleuthing on your own. The first place to start is the INCI list. Go to the INCI decoder to start your search. A lot of times they’ll have descriptions of where to go and some references if you’d like to dig deeper. And remember the CAS number? That’s your second step for investigation. Type that number into google or a chemical supplier website like guidechem or chemicalbook and you’ll get all the information you’d ever want on a chemical. Basically, what you want to look at is the material data safety sheet (MSDS). That is a standardized collection of everything known about the chemical in question- its toxicity, how to handle the chemical safely, its physical characteristics, its disposal, what to do if it’s ingested, etc. But I have to caution you here- to paraphrase Paracelsus, “the dose makes the poison.” Remember, high concentrations of a surfactant will be irritating and cause harm to wildlife if dumped in your local creek. But it doesn’t mean that it is dangerous in low concentrations in your gel cleanser. And beware of the idea that organic ingredients are somehow better than synthetic chemicals. Lots of things from nature are dangerous and can cause harm (and allergic reactions).
In essence, it’s really hard to know what is “safe” and what isn’t. A great example is octinoxate, a UV blocking chemical common in chemical sunscreens (and remember- the FDA considers sunscreens OTC drugs). In a 2020 manuscript in the Journal of the American Medical Association (JAMA), researchers showed that octinoxate and six other chemicals commonly found in sunscreens were absorbed into the bloodstream at levels that exceed FDA safety thresholds (read the CNN synopsis of the study here). In fact, octinoxate was detected at high levels in plasma 21 days after only one application! The reason people are concerned about this is that a lot of these chemicals have incomplete safety studies. Many of them, including octinoxate, are endocrine disruptors and may affect hormone signaling. So, is it “safe?” Well, these chemicals do prevent UV damage to the skin, so they are helpful in preventing skin cancer. But the jury’s still out on if these should be banned due to their possible effects on the endocrine system. They are still in common chemical sunscreens; they have not been banned by the FDA. My advice (and the advice of most dermatologists)? Avoid them and just use a mineral sunscreen with zinc oxide or titanium dioxide, which work as a physical barrier that reflects UV rays versus getting absorbed into the skin. The SPF test is the same for all those products (and regulated by the FDA’s monograph rules), so why not use a potentially less toxic version of an SPF 30 sunscreen if you have a choice? Bonus? It’s better for reefs if you’re out in the water. In fact, many locations like Hawaii have banned these chemicals for their potential environmental hazards in the ocean.
So how does the INCI listing help me?
In conclusion, it’s hard to say exactly what’s in your cosmetic product. But, the INCI is the best place to start. It tells you what is in the cosmetic product, and relative abundance in comparison to other things in the mix, allowing you to at least gauge your comfort with the amount of something you may find suspect (like a fragrance, for instance). The rest is really up to you as the consumer- if you’re interested, go to the INCI and chemical websites and dig deeper for information about chemicals you may be interested in. Remember- the FDA doesn’t really regulate this- it’s up to the consumer. I advise you to stick with brands that you trust are doing their due diligence to research the safety and efficacy of the chemicals they use in their products. As the Russian proverb says, “trust, but verify.” Ultimately it’s your skin and health. So start with the INCI, but don’t be afraid to investigate further.
