Cosmetic, Supplement, or Drug? The Three Categories That Explain Everything

By Dr. Susan Lin, MD | MD HAIR | La Cañada Ventures, Inc.
Published on mdhair.com — The Physician Behind MD HAIR Series

You are standing in the hair aisle holding two boxes that look almost identical. Same size. Same clinical typeface. Same word — advanced — in the same place on the front. One costs $34 and one costs $58, and neither of them tells you the single fact that would explain the difference.

Turn them both over. One has a panel headed Drug Facts. The other does not.

That panel — or its absence — is the most informative thing on either box. It tells you which body of United States law the product was built inside, what it was permitted to promise you, whether anyone at a federal agency reviewed the promise before it reached the shelf, and what recourse exists if it does nothing. It explains why the cheaper box can say regrows hair and the expensive one, with far more interesting ingredients in it, can only say supports the appearance of fuller-looking hair.

I am Dr. Susan F. Lin, M.D. — trained at Boston University School of Medicine, board-certified in Obstetrics & Gynecology and in Anti-Aging Medicine, and the physician behind the MD® line at La Cañada Ventures, Inc. since 2008. I have spent nearly two decades writing labels inside these rules and having them reviewed by people whose job is to find the sentence that goes too far.

This article is the map I wish every customer had before they read a single one of my product pages. Once you have it, most of the confusion in this category resolves — including the confusion about my own products, which I will place explicitly in their categories at the end.

The Three Categories

United States law does not have a category called hair product. It has a small number of very old definitions, and every bottle in that aisle has been sorted into one of them.

1. Cosmetics

Under the Federal Food, Drug, and Cosmetic Act, a cosmetic is an article intended to be applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance (FD&C Act § 201(i)).

That definition is doing something specific: it is a definition about appearance. Not about disease, and — this is the part almost nobody knows — not about biological function either.

What review does a cosmetic get before it reaches you? No FDA pre-market approval. There is no application, no dossier, no agency sign-off. The manufacturer is responsible for the safety of the product and the truthfulness of its claims, and the FDA's authority is largely exercised after the fact (FDA).

Two genuine exceptions are worth knowing. Color additives used in cosmetics generally must be FDA-approved and, for some, batch-certified — which is why a lipstick pigment gets a level of federal scrutiny that a botanical extract in the same tube does not (FDA, Color Additives). And the Modernization of Cosmetics Regulation Act of 2022 (MoCRA) added meaningful obligations: facility registration, product listing, adverse event reporting, and — importantly — a requirement that manufacturers keep records adequately substantiating the safety of their products. MoCRA is the largest change to United States cosmetics law since 1938, and it is still being implemented (FDA, Cosmetics & U.S. Law).

What MoCRA did not do is create pre-market approval. There is still no such thing as an FDA-approved cosmetic.

2. Dietary Supplements

Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), a dietary supplement is a product taken by mouth containing a dietary ingredient — a vitamin, mineral, herb or botanical, amino acid, or a concentrate or extract of one — intended to supplement the diet (DSHEA, Public Law 103-417). In law, a dietary supplement is treated as a category of food, not as a drug.

What review does a supplement get? Again, no FDA pre-market approval. A manufacturer does not submit a supplement for authorization before selling it.

There are structures around that, and they are worth naming precisely because they are so often misdescribed:

• cGMP for supplements (21 CFR Part 111) governs identity testing, purity, batch records, contamination control and label accuracy. This is a manufacturing regulation, not a product approval.
• New Dietary Ingredient (NDI) notification applies to ingredients not marketed in the United States before 15 October 1994. A notification is a filing the FDA receives. It is not an approval, and a company describing one as an approval has told you something about how it reads documents (FDA, NDI process).
• Structure/function claims must be truthful and substantiated, are notified to the FDA within 30 days of first marketing, and must carry the DSHEA disclaimer: "This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease."

That disclaimer is not decoration and it is not a legal shrug. It is the price of admission for a whole category of permitted language, and I will spend an entire separate article on it.

3. Drugs

A drug is defined by intent, in two limbs. 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 (FD&C Act § 201(g)).

Read that second limb again, because it is the hinge on which this entire article turns. Affecting the structure or function of the body is, by itself, enough to make something a drug. Dietary supplements escape that limb through a statutory carve-out written into DSHEA. Cosmetics have no such carve-out.

What review does a drug get? Real, adversarial, pre-market review. A New Drug Application requires substantial evidence of effectiveness and adequate evidence of safety, generated in adequate and well-controlled investigations, reviewed by the agency before marketing. Some non-prescription categories instead sit under OTC monograph orders. Either way, a human being at the FDA reads the evidence and can say no.

Topical minoxidil is the relevant example in our category: it is sold over the counter, and it got there through drug review rather than by being classified as a cosmetic (Olsen et al., 2002). Over the counter and unreviewed are not synonyms.

There is also a provision most people have never heard of that explains a great deal about this aisle: 21 CFR 310.527 provides that over-the-counter drug products labelled for hair growth or for prevention of hair loss are not generally recognized as safe and effective. In plain terms, the FDA closed the door on unapproved OTC hair-growth drugs decades ago. That is precisely why the cosmetic aisle is full of careful appearance language rather than growth promises — and why a product making a growth promise without drug approval is not being bold. It is being non-compliant.

The Fourth Category People Forget: Devices

Laser combs, laser caps, and LED helmets for hair are medical devices, and devices have their own vocabulary that is routinely and profitably mangled.

Most such products reach market through 510(k) premarket notification, in which a manufacturer demonstrates substantial equivalence to a legally marketed predicate device (FDA, 510(k)). The outcome of a successful 510(k) is clearance. Clearance is not approval. Approval (PMA) is a different, far heavier pathway reserved mainly for the highest-risk devices, and a De Novo request results in marketing authorization, which is a third thing again.

If a laser cap's marketing says FDA approved, the marketing is wrong. If it says FDA cleared, it is probably right — and you should then ask what it was found equivalent to, because substantial equivalence is a comparison, not an efficacy finding.

What Determines the Category Is Intended Use — Not Ingredients

Here is the fact that makes the whole system intelligible, and it surprises nearly everyone.

A product's category is determined by what it is intended to do — and its claims are the primary evidence of that intent.

The same jar of cream, with the same formula, is a cosmetic if it says smooths the appearance of fine lines and a drug if it says treats wrinkles caused by photodamage. Nothing in the jar changed. The regulatory status changed because the sentence changed.

The FDA's regulations on intended use are explicit that objective intent may be shown by labelling, advertising, oral or written statements, and the circumstances of distribution — including what the seller knows about how consumers actually use the product (21 CFR § 201.128). A brand cannot put a drug claim in a TikTok video and a cosmetic claim on the box and expect the box to control.

Two consequences follow, and both matter to you as a buyer.

First, a product can be more than one category at once. An anti-dandruff shampoo is a cosmetic (it cleanses) and a drug (it treats a condition, via an active such as ketoconazole or pyrithione zinc). Those products carry both cosmetic ingredient labelling and a Drug Facts panel, which is why the back of an anti-dandruff bottle looks so much busier than the back of a conditioner (FDA, Is It a Cosmetic, a Drug, or Both?).

Second, a brand can talk itself into a category it never intended to enter. Most FDA warning letters in the beauty and supplement space are not about what is in the bottle. They are about sentences. Stimulates growth. Prevents loss. Reverses thinning. Clinically proven to treat alopecia. Each of those asserts drug status, and asserting drug status without approval is the violation — the ingredients are frequently beside the point.

The Practical Tell: Turn the Box Over

Everything above collapses into one physical action. Turn the package over and look for a boxed panel.

Drug Facts. A standardized panel required for over-the-counter drug labelling (21 CFR 201.66), with fixed headings in a fixed order: Active ingredient(s), Purpose, Uses, Warnings, Directions, Inactive ingredients. If you see it, you are holding a drug. The Uses line will tell you, in agency-vetted language, exactly what it is permitted to be for.

Supplement Facts. The panel required for dietary supplements (21 CFR 101.36) — serving size, amount per serving, % Daily Value where one exists, and a list of dietary ingredients without DVs beneath a horizontal rule. If you see it, you are holding a supplement, and the DSHEA disclaimer will be nearby.

Nutrition Facts. A conventional food.

Neither panel, just an ingredient list in descending order. A cosmetic. Cosmetic ingredient declaration (21 CFR 701.3) lists ingredients in descending order of predominance — but only down to 1%, below which ingredients may appear in any order, with colour additives last. This is why a hero botanical can sit legally at a trivial percentage between two preservatives and still headline the front of the box. The ingredient list tells you what is present. It does not tell you how much, and past the 1% line it does not even tell you the order.

Why a Cosmetic Legally Cannot Say What a Drug Says

Customers write to us, in effect: just tell me if it works. I understand the frustration completely, and I want to explain why the answer you want is one I am not entitled to give.

A drug earned its sentence. To say regrows hair, a sponsor ran adequate and well-controlled investigations, submitted them, and had them reviewed by people empowered to refuse. The sentence is short because the file behind it is enormous. When you read a Drug Facts Uses line, you are reading the compressed output of that process.

A cosmetic has no such file, because the law does not provide a route to build one. There is no application through which a cosmetic can submit evidence and be granted permission to say regrows hair. If a topical product's intended use is to regrow hair, it is not a cosmetic at all — it is an unapproved drug. The claim does not require better evidence. It requires a different regulatory identity, and the moment you make it, you have adopted that identity whether you meant to or not.

So when you see a cosmetic making a growth claim, three explanations exist. It is an approved drug and you have misread the box. It is non-compliant. Or the sentence is more carefully constructed than it looks — supports the appearance of fuller-looking hair, where every word is load-bearing.

And when you see a cosmetic making a modest claim, do not read that as weak evidence. It may be — but it may equally be a brand staying inside the only category available to it. The claim ceiling in this aisle is set by statute, not by the strength of the formula. That is the single most useful thing to understand about reading hair-product labels, and it took me years of doing this to explain it in one sentence.

The corollary is uncomfortable for me and I am going to say it anyway: the category constrains the claim, but it does not certify the product. A modest, compliant claim is not evidence of anything by itself. Every brand in the cosmetic aisle is constrained the same way, including the ones with nothing in the bottle. The constraint is why you cannot use claim strength to compare products — and why you have to go and look at the actual evidence instead.

Where Every MD Product Sits

I am not going to explain a taxonomy and then leave you to guess where I fall inside it.

MD Nutri Hair™ — a dietary supplement. It carries a Supplement Facts panel: serving size one capsule, a Proprietary Blend of 300 mg, with Vitamin B3 as niacinamide at 5 mg, alpha tocopheryl acetate at 5 mg, and D-biotin at 0.05 mg. Other ingredients: flaxseed powder, lignan powder, lilac. It is regulated under DSHEA, receives no FDA pre-market approval, and any statement we make about it is a structure/function statement carrying the required disclaimer.

Two things follow that I would rather say myself than have you find. Proprietary Blend 300 mg means the individual amounts of flaxseed, lignan and lilac are not disclosed — that is a real limitation of our transparency and I have written about it elsewhere under my own name. And the label instructs: adults only, one capsule daily, and do not take if you are pregnant or breast feeding.

The topicals — cosmetics. MD Scalp Essential, MD Follicle Energizer, MD Follicle Activator, MD Revitalizing Shampoo and MD Revitalizing Conditioner are cosmetics. Ingredient lists, no Drug Facts panel, no drug actives, no FDA pre-market approval, and appearance-scoped claims because that is the category's ceiling.

The kits and bundles — a mixed box. The MD HAIR™ Restoration Kit and Restoration System combine cosmetics with the supplement. A box containing both does not create a fourth category; each component is regulated as what it is.

What none of them are. No MD product is FDA approved, and no cosmetic or dietary supplement on the United States market is. Our products are manufactured in FDA-registered, GMP-compliant facilities — and I want to be exact about what that sentence means, because the industry blurs it deliberately. Registered describes the facility: the FDA knows it exists and may inspect it. It says nothing whatever about the product being reviewed, authorized, or approved. A brand that lets FDA-registered facility drift into FDA approved has told you how it handles every other sentence on its label.

None of our products are intended to diagnose, treat, cure, or prevent any disease.

The Bottom Line

United States law sorts everything in the hair aisle into a small number of very old definitions, and the sorting is done by intended use, evidenced by claims — not by ingredients, price, or how scientific the packaging looks.

Cosmetics are for cleansing, beautifying and altering appearance. No pre-market approval; the manufacturer carries responsibility for safety and truthfulness. Dietary supplements sit under DSHEA, also with no pre-market approval, permitted structure/function claims, and a mandatory disclaimer. Drugs are defined by an intent to treat disease or to affect the structure or function of the body, and they undergo genuine pre-market review. Devices are cleared through 510(k) — which is not approval, and never was.

The tell is the panel. Drug Facts means drug. Supplement Facts means supplement. An ingredient list alone means cosmetic. Thirty seconds and a box in your hand will out-perform an hour of reading marketing copy.

And the most important consequence: a cosmetic that promises to regrow hair is not a confident cosmetic. It is a product that has quietly claimed drug status without doing any of the work. The careful phrasing you find irritating on honest labels — mine included — is the boundary of a category, not the boundary of a company's nerve.

Dr. Susan Lin's Clinical Perspective

"The question I am asked most often is 'why won't you just say it regrows hair,' and the honest answer is that the sentence is not mine to say. It belongs to a category I am not in, and the only way into that category is a drug application with adequate and well-controlled investigations behind it. What troubles me is not the constraint — the constraint is reasonable — but that consumers read claim strength as evidence strength. They are almost inversely related in this aisle. The boldest hair claims tend to come from the products with the least accountability, because a brand willing to ignore the category line has already told you it will ignore the evidence line too. I would rather a patient understood the map than trusted my restraint. Restraint is not a virtue signal. It is what compliance looks like from the outside."

— Dr. Susan F. Lin, M.D., Physician Formulator, MD HAIR

Mechanism Spotlight: How a Product Changes Category Without Changing Its Formula

Take an ordinary conditioner: cationic surfactants, fatty alcohols, silicones, a botanical extract at half a percent. Applied to hair, it deposits a thin conditioning film, reduces static, smooths the cuticle and lowers combing friction. Fibres separate less, reflect light more evenly, and occupy slightly more visible volume. Hair looks fuller. Every one of those effects is real, measurable, and entirely on the fibre — the hair shaft is dead keratin, and altering how it behaves is exactly what altering the appearance means. Cosmetic, unambiguously.

Now change nothing in the jar and write stimulates dermal papilla activity to restore anagen on the front. You have made a claim about a living structure at the base of the follicle and about the hair cycle itself — the second limb of the drug definition, structure or function, with no DSHEA carve-out available because this is a topical cosmetic and not a supplement. The formula is identical. The regulatory identity is not.

This is why the category line is drawn where it is, and it maps onto a genuine biological boundary. Above the skin, you are working on a dead fibre and its optics: legitimately, usefully, cosmetically. Below the stratum corneum — the dense lipid-and-keratinocyte barrier that keeps foreign molecules out, and that most molecules above roughly 500 daltons cross very poorly (Bos & Meinardi, 2000) — you are in living tissue, in the follicle's own biology, and the law treats that as a different kind of intervention requiring a different kind of proof.

So the next time a product's copy slides from how your hair looks to what is happening inside your follicle, notice the moment it crosses. That sentence has changed categories. The question worth asking is whether the evidence crossed with it.

Recommended Reading

Pillar pages on mdhair.com:

• The Clinical Evidence Behind MD HAIR
• Drug-Free Hair Loss Treatment — The Complete Guide
• About Dr. Susan Lin, M.D. — The Physician Behind MD®
• The Scalp Health Guide

Related articles in this series:

• Drug-Free and Natural Are Not the Same Word — the five-second Drug Facts check, and why natural is not a category
• Plant Stem Cell Culture and Why Standardization Beats Potency — how to read an ingredient claim once you know its category
• Drug-Free Hair Growth: Does It Actually Work Without Minoxidil? — what choosing the cosmetic and supplement categories costs, stated plainly

Our sister site md-factor.com publishes the same regulatory documentation for the wider MD® portfolio, under the same standard of disclosure.

MD HAIR Product Recommendation

None. This article exists to make the rest of the site legible, and ending it with a purchase would undercut that.

Two links instead, both of which invite you to check us rather than trust us:

The Clinical Evidence Behind MD HAIR — what our studies are, what tier they sit at, and what they do not establish. Now that you know MD Nutri Hair™ is a dietary supplement and the topicals are cosmetics, you know exactly what class of evidence to expect and exactly what claims we are permitted to make. Read the page against that expectation.

The MD HAIR Quiz — a structured way to work out what is actually driving your hair change, including the outcomes where the honest answer is a physician and a lab panel rather than any product, ours included. If what you have is a disease, you need the drug category, and you need a doctor — not a cosmetic.

A note on authenticity: genuine MD HAIR™ and MD Nutri Hair™ products are sold only through mdhair.com, md-factor.com, and the official La Cañada Ventures, Inc. stores on Amazon and Walmart. We cannot verify the storage, handling, labelling or lot integrity of units bought anywhere else — and a product whose label we did not print is a product whose category we cannot vouch for.

References

1. U.S. Food and Drug Administration. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?). fda.gov
2. Federal Food, Drug, and Cosmetic Act § 201(i) (cosmetic) and § 201(g) (drug), 21 U.S.C. § 321. law.cornell.edu
3. U.S. Food and Drug Administration. FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated. fda.gov
4. U.S. Food and Drug Administration. Cosmetics & U.S. Law — including the Modernization of Cosmetics Regulation Act of 2022 (MoCRA). fda.gov
5. U.S. Food and Drug Administration. Color Additives and Cosmetics. fda.gov
6. Dietary Supplement Health and Education Act of 1994, Public Law 103-417 (full text, NIH Office of Dietary Supplements). ods.od.nih.gov
7. 21 CFR § 101.36 — Nutrition labeling of dietary supplements (Supplement Facts panel). eCFR
8. 21 CFR § 201.66 — Format and content requirements for over-the-counter drug product labeling (Drug Facts panel). eCFR
9. 21 CFR § 701.3 — Designation of ingredients (cosmetic ingredient declaration). eCFR
10. 21 CFR Part 111 — Current Good Manufacturing Practice for Dietary Supplements. eCFR
11. 21 CFR § 310.527 — Drug products containing active ingredients offered over-the-counter for hair growth or for hair loss prevention. eCFR
12. 21 CFR § 201.128 — Meaning of intended uses. eCFR
13. U.S. Food and Drug Administration. New Dietary Ingredient (NDI) Notification Process. fda.gov
14. U.S. Food and Drug Administration. Premarket Notification 510(k). fda.gov
15. U.S. Food and Drug Administration. Premarket Approval (PMA). fda.gov
16. U.S. Food and Drug Administration. Cosmetics Labeling Claims. fda.gov
17. U.S. Federal Trade Commission. (2022). Health Products Compliance Guidance. ftc.gov
18. Bos JD, Meinardi MMHM. (2000). The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Experimental Dermatology, 9(3), 165–169. PMID 10839713
19. Olsen EA, Dunlap FE, Funicella T, et al. (2002). A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in men. Journal of the American Academy of Dermatology, 47(3), 377–385. PMID 12196747

Dr. Susan F. Lin, M.D. is the physician formulator behind MD HAIR and MD Nutri Hair™, product lines of La Cañada Ventures, Inc. — physician-formulated since 2008 under the MD® mark (U.S. Reg. No. 4,471,494). She trained at Boston University School of Medicine and is board-certified in Obstetrics & Gynecology and in Anti-Aging Medicine (A4M).

MD® products are cosmetics and dietary supplements manufactured in FDA-registered, GMP-compliant facilities. "FDA-registered" describes the facility, not the product: these products are not FDA approved, and no cosmetic or dietary supplement is. Individual results vary. MD Nutri Hair™ is a dietary supplement. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Because there are no clinical data in pregnant or breastfeeding women, we do not advocate using MD HAIR products during pregnancy or lactation.

This article is for educational purposes, describes United States regulatory categories in general terms, and is neither medical nor legal advice. Consult your own physician for personalized guidance.

Explore more in The Physician Behind MD HAIR series at mdhair.com/pages/dr-susan-lin