Eyelash serum advertising rules: cosmetic claims vs drug claims

Lash and brow products sit on the retail shelf of med spas, dermatology offices, eye care practices and salons inside medical buildings. A conditioning serum, a prescription eyelash drug, a brow tint and a set of extensions can all end up on the same menu under the word “lash.” Federal law treats them very differently, and the difference turns on what you say the product does. “Makes lashes look fuller” and “grows longer lashes” are not the same claim.

This guide covers where the cosmetic and drug line falls for lash and brow products, what FDA approved for eyelash growth, how to talk about the prescription product without overreaching, what FDA says about lash tints and extensions, and how the FTC Act applies to results, photos and prices. For practice-branded retail in general, see our guide to private-label supplements and skincare. For the retail side of a practice, see selling supplements in a medical practice.

The short version

• Intended use decides the category. A cosmetic is for “beautifying, promoting attractiveness, or altering the appearance” (21 USC 321(i)). A product intended to affect the structure or any function of the body is a drug (21 USC 321(g)(1)(C)). FDA says claims like restoring hair growth make a product a drug, even if it is marketed as a cosmetic.
• “Eyelash growth” is a drug claim. FDA has issued warning letters citing drug claims on products marketed as cosmetics, and its list of examples includes “eyelash growth.”
• One prescription drug class is approved for lashes. Drugs@FDA lists a prescription eyelash solution approved December 24, 2008. Its labeling indicates it to treat hypotrichosis (inadequate or not enough) of the eyelashes by increasing their growth, including length, thickness and darkness. It is not labeled for eyebrows.
• Tints and extensions have their own FDA rules. FDA warns that permanent lash and brow tints have been known to cause serious eye injuries, and it has provided for silver nitrate as a color additive in professional-use-only lash and brow tints, with conditions.
• Results, risks and photos follow the FTC Act. Claims about length, speed and safety need evidence (15 USC 45, 52), and leaving out material risks can make an ad misleading (15 USC 55(a)(1)).

Where the cosmetic and drug line falls

The Federal Food, Drug, and Cosmetic Act defines a cosmetic as an article intended to be applied to the body “for cleansing, beautifying, promoting attractiveness, or altering the appearance” (21 USC 321(i)). It defines a drug to include articles intended to diagnose, cure, mitigate, treat or prevent disease, and articles “(other than food) intended to affect the structure or any function of the body” (21 USC 321(g)(1)(B) and (C)).

FDA’s page Is It a Cosmetic, a Drug, or Both? says a product’s category is determined by its intended use, and that intended use can be established by claims on the labeling, in advertising, on the Internet or in other promotional materials, by consumer perception, and by ingredients with a well-known therapeutic use. Its list of claims that make a product a drug includes claims that a product will “restore hair growth.” The same page says a product can be both a cosmetic and a drug, and then it must meet the requirements for both.

For lash and brow products, that gives a practical sorting rule for your copy:

• Appearance claims fit a cosmetic: “lashes look longer,” “conditions and coats lashes,” “adds the look of fullness,” “tints brows.” They still have to be true.
• Growth or biology claims point to a drug: “grows lashes,” “stimulates the lash follicle,” “extends the growth phase,” “regrows thinning brows,” “treats lash loss after chemotherapy.” A product sold with those claims needs to be an approved drug for that use.
• Ingredient talk counts. Saying a serum contains a growth-promoting or “prescription-strength” ingredient, or comparing it to the prescription lash drug, signals drug intended use under FDA’s description of how intended use is shown.

This applies to your website, your social posts, the shelf card and what staff say at checkout, not just the box. Our guide to private-label skincare covers who is responsible for label claims when a product carries your practice’s name.

What FDA has said about lash serum claims

FDA’s page on warning letters addressing drug claims made for products marketed as cosmetics (archived copy, page last updated August 9, 2018) explains that a product intended to affect the structure or function of the body is a drug, and that a drug not generally recognized as safe and effective for its labeled use is a “new drug” that needs an approved application to be marketed legally. It lists warning letters citing drug claims on topical skin care, hair care, and “eyelash/eyebrow preparations,” on both product labeling and websites. Its examples of drug claims cited include “eyelash growth.” The list includes two letters, both from 2011, under the heading for eyelash and eyebrow treatments.

Those letters went to the companies selling the products. A practice that puts its own name on a serum, or writes its own growth claims for a product it sells, is the one making the claim. If a vendor’s serum is sold to you as a cosmetic but its marketing kit says it “grows lashes in 4 weeks,” do not repeat that kit on your pages.

The prescription eyelash drug

Drugs@FDA, read through openFDA on November 1, 2026, lists a prescription eyelash solution approved on December 24, 2008, and openFDA’s labeling data includes generic versions with the same indication. The labeling (effective July 1, 2024) describes a prostaglandin analog “indicated to treat hypotrichosis of the eyelashes by increasing their growth including length, thickness and darkness.” It is applied nightly to the skin of the upper eyelid margin at the base of the lashes with a single-use sterile applicator, and the labeling says not to apply it to the lower lash line.

Points from the labeling that matter for marketing:

• Results stop when use stops. The labeling says that “upon discontinuation of treatment, eyelash growth is expected to return to its pre-treatment level.” “Permanent lashes” does not fit.
• More is not more. It says additional applications will not increase lash growth.
• Known effects. Warnings include increased brown iris pigmentation, which is likely to be permanent; darkening of the eyelid skin; hair growth where the solution repeatedly touches other skin; and effects on eye pressure in patients using pressure-lowering eye drops. Its most common adverse reactions are listed as eye itching, eye redness and skin darkening.
• Eyelashes only. The indication is for eyelashes. Using it on brows is a use FDA has not approved, so do not advertise “brow growth” with it as if it were approved.
• It is a prescription drug. A patient needs an evaluation and a prescription, so the ad should lead to a consultation, not a “buy now” button.

FDA’s rule on prescription drug advertisements (21 CFR 202.1) sets requirements such as a fair balance of risk and benefit information and limits on suggesting uses outside the approved labeling. It is written for the manufacturer, packer or distributor of the drug, and we found no FDA rule that applies it to a practice’s own service ads as such. The FTC Act applies to the practice either way. Our guide to prescription treatment advertising explains that split. A practical approach: describe the drug by its approved use, mention that it needs a prescription and has side effects, and send people to a consultation. Leave brand names to the manufacturer’s own materials unless your counsel has reviewed how you use them.

“Just like the prescription, without a prescription”

A common retail pitch compares a cosmetic serum to the prescription drug: “prescription results without the prescription,” “the natural alternative,” “same lash growth, no side effects.” Each piece is a problem. A growth comparison is a drug claim under FDA’s description of intended use. “Same results” needs head-to-head evidence. “No side effects” is a safety claim that needs competent and reliable scientific evidence under the FTC guidance, and cosmetics applied near the eye can still cause irritation and allergic reactions, as FDA’s eye cosmetics page notes for lash adhesives. If the serum contains an ingredient related to the prescription drug, the comparison becomes harder to defend, not easier. Ask your vendor for the full ingredient list and keep it on file.

Lash tints, brow tints and extensions

FDA’s Eye Cosmetic Safety page (content current as of June 28, 2022) covers services that often sit next to serums on a lash menu:

• Tints and dyes. FDA says permanent eyelash and eyebrow tints and dyes “have been known to cause serious eye injuries, including blindness.” It says FDA has provided for one color additive, silver nitrate, in professional-use-only cosmetics to color eyebrows and eyelashes, at up to 4 percent, not for people under 16, not applied for longer than 1 minute, and not sold directly to consumers (21 CFR 73.2550). It also notes an import alert for eyelash and eyebrow dyes containing coal tar colors.
• Extensions and adhesives. FDA considers false eyelashes, eyelash extensions and their adhesives to be cosmetics that must meet cosmetic safety and labeling requirements, and it reminds consumers that eyelids are delicate and that allergic reactions and irritation near the eye are a concern.

For marketing, do not call a tint “FDA-approved” or “completely safe,” and do not sell take-home tint kits that are meant for professional use only. If your practice offers tinting, ask your supplier which color additive the product uses and whether it is permitted for use near the eye.

Results, timelines and risks

The FTC Health Products Compliance Guidance says health-related claims require competent and reliable scientific evidence, and that marketers are responsible for implied claims as well as express ones. For lash and brow products:

• Length and fullness numbers. “Up to 50 percent longer lashes” or “twice as thick” are objective claims. You need evidence for the specific product, and “up to” claims can imply that patients will commonly get the top figure.
• Timelines. “Visible results in 2 weeks” needs evidence for that product and timeline.
• Permanence. For the prescription drug, the labeling says growth returns to its pre-treatment level after stopping. For a cosmetic, a permanence claim implies a change to lash growth, which is a drug claim.
• Risks. Under 15 USC 55(a)(1), whether an ad misleads includes what it fails to reveal about the consequences of using the product. For the prescription drug, eye color change and eyelid darkening are material. For any lash product, irritation and allergic reactions are worth a line.
• Medical conditions. Claims about lash loss from chemotherapy, alopecia, thyroid conditions or eye disease are disease claims. Keep them out of cosmetic marketing and send those patients to a clinician.

Before and after photos and reviews

Under 16 CFR 255.2(a), an advertiser needs substantiation for what consumer endorsements convey, as if it had made the claims itself. Under 16 CFR 255.2(b), an endorsement about a central or key attribute is likely to be read as representative of what consumers generally achieve, unless the ad clearly and conspicuously discloses the generally expected results. Lash photos are easy to distort: mascara, extensions, curling, camera angle and lighting all change how lashes look. Show bare lashes in both photos with the same angle and light, say how long the product was used and which product it was, do not retouch, get written permission, and note that results vary. A photo of the prescription drug’s results cannot sell a cosmetic serum, and an extension photo cannot sell a serum. Our guide to patient testimonials and before-and-after photos covers consent and privacy.

Prices, subscriptions and bundles

Lash serums are often sold as refills or subscriptions. State the price per bottle, how long a bottle is expected to last under the directions, and the renewal terms. A “was $150, now $99” offer needs a former price you actually offered in good faith for a reasonably substantial period of time (16 CFR 233.1(a)). For the prescription product, keep the consultation fee and the drug cost separate in the ad so the total is not a surprise. See our guide to was and now price claims.

An example (made up)

This illustration is invented to show how the rules fit together. A med spa posts: “Grow longer, thicker lashes and brows in 4 weeks with our natural lash serum! Same results as the prescription, no side effects, no prescription needed. Results are permanent. $89, was $160.” The serum is sold to the med spa as a cosmetic conditioning serum. The post shows a before photo without makeup and an after photo with mascara.

Fixes: “grow,” “4 weeks” and “permanent” make growth claims that a cosmetic cannot carry, so the copy becomes appearance language such as “conditions lashes so they look fuller,” and only if that is true. “Same results as the prescription” and “no side effects” go. The photos are retaken with bare lashes in both, same light and angle, with the time of use stated. The $160 former price stays only if customers actually paid it for a reasonable period. If the med spa also offers the prescription eyelash drug, that goes on a separate page that describes the approved use, the prescription step and the side effects, and leads to a consultation.

Checklist

• You know which lash products are cosmetics and which are drugs, by what each one is sold to do (21 USC 321(g)(1), (i)).
• Cosmetic serums carry appearance claims only: no growth, follicle, growth-phase or regrowth claims (FDA, Is It a Cosmetic, a Drug, or Both?).
• No comparisons of a cosmetic serum to the prescription drug’s results.
• The prescription eyelash drug is described by its approved use (eyelash hypotrichosis), with a prescription step and its main side effects, not for brows (labeling via openFDA).
• No “permanent” lash claims; the drug’s labeling says growth returns after stopping.
• Tints are professional-use only, use a permitted color additive, and are not called FDA-approved or completely safe (FDA, Eye Cosmetic Safety).
• Length, thickness and timeline claims have evidence for that product (15 USC 45, 52; FTC guidance).
• Risks such as irritation, allergic reactions and, for the drug, eye and eyelid color changes are mentioned (15 USC 55(a)(1)).
• Before and after photos use bare lashes, the same setup, the stated product and time, consent, and typical results (16 CFR 255.2).
• Prices state per-bottle cost, how long a bottle lasts, and renewal terms; former prices were real (16 CFR 233.1).
• Who may prescribe, dispense or apply each product checked against your state’s rules.

How we help

We build retail and service pages for med spas, dermatology and eye care practices with product categories and claims checked against the sources above: website design, healthcare SEO for treatment and product searches, and lead generation campaigns that send prescription interest to a consultation. We do not decide whether a product is a cosmetic or a drug, we do not give legal opinions, and we are not a law firm. For other aesthetic topics, see our guides to med spa marketing ideas and dermatology practice marketing.

Sources

• 21 USC 321: Definitions (drug, cosmetic)
• FDA: Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?) (content current as of September 11, 2024)
• FDA: Warning Letters Address Drug Claims Made for Products Marketed as Cosmetics (page last updated August 9, 2018, archived copy)
• FDA: Eye Cosmetic Safety (content current as of June 28, 2022)
• FDA: Drugs@FDA database
• openFDA Drugs@FDA data (last updated October 30, 2026)
• openFDA drug labeling data (label effective July 1, 2024)
• 21 CFR 73.2550: Silver nitrate (color additive)
• 21 CFR 202.1: Prescription-drug advertisements
• 15 USC 45: Unfair methods of competition unlawful
• 15 USC 52: Dissemination of false advertisements
• 15 USC 55: Additional definitions
• FTC: Health Products Compliance Guidance (December 2022)
• 16 CFR 255.2: Consumer endorsements
• 16 CFR 233.1: Former price comparisons

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