What a peptide sold as a cosmetic is held to

The category nobody explains on the product page

A peptide in a serum and the same peptide in a vial can be governed by completely different rules. The serum is usually sold as a cosmetic, and cosmetics have their own labeling regime.

That regime was rewritten by a 2022 statute, which the agency describes as "the most significant expansion of FDA's authority to regulate cosmetics" since the food and drug law was passed in 1938.

What changed is mostly about records, registration and reporting rather than about proof. Understanding what did and did not change is the useful part.

Elsewhere this site covers what the cosmetic research literature supports, and leaves the question of what a cosmetic seller must do unanswered. That is what follows here.

The warning that appears when safety was not substantiated

The single most checkable thing on a cosmetic label comes from a short regulation, and it is a sentence you can look for by eye.

The rule opens by placing a duty. "Each ingredient used in a cosmetic product and each finished cosmetic product shall be adequately substantiated for safety prior to marketing."

Then it supplies the consequence. A product whose safety is not adequately substantiated before marketing is misbranded, unless it carries a conspicuous statement on the principal display panel.

The regulation writes the statement out in full: "Warning—The safety of this product has not been determined." A label bearing that line is telling you something specific about itself.

The narrow exception to that warning

The rule anticipates a situation where new information arrives about a long-used ingredient, and it does not require the warning in that case.

Three conditions all have to hold. Safety had been adequately substantiated before the new information appeared. The new information "does not demonstrate a hazard to human health." And adequate studies are being conducted to settle the question quickly.

The regulation then closes the door on a wider reading. That exception "does not constitute an exemption to the adulteration provisions of the Act or to any other requirement."

A separate rule sits alongside it. A cosmetic label has to bear a warning statement "whenever necessary or appropriate to prevent a health hazard that may be associated with the product."

What the ingredient list is required to be

Cosmetic ingredient labeling has real structure, and knowing the structure lets you read the panel properly.

Ingredients appear "in descending order of predominance," with a stated exception: fragrance or flavor may be listed simply as fragrance or flavor.

The declaration also has to be legible in a defined way. It must appear "with such prominence and conspicuousness as to render it likely to be read and understood by ordinary individuals under normal conditions of purchase." The letters may be no smaller than one sixteenth of an inch.

And ingredient names are not free text. They come from a named list established for cosmetic ingredient labeling, and where that list does not have a name, from specified compendia in a stated order of preference.

The phrase that hides an ingredient legally

One provision explains a phrase that appears at the end of some ingredient lists and looks like sloppiness.

One or more ingredients may be accepted by the agency as exempt from public disclosure, through a specified procedure. The label may then use "and other ingredients" at the end of the declaration instead of naming them.

So that phrase is not a gap in the list. It marks ingredients whose identity has been formally exempted, by an accepted request rather than by a seller's choice.

It is still a limit on what you can check. A list ending that way is complete in the legal sense and incomplete in the practical one.

What the 2022 law added

The newer duties are about a company rather than a carton, and they create records that did not exist before.

Facilities that manufacture or process cosmetics must register with the agency and renew that registration every two years. A responsible person must list each marketed product, including its ingredients, and update that listing annually.

Serious adverse events must be reported. The agency states the deadline plainly: a responsible person reports serious adverse events associated with use of cosmetic products in the United States "within 15 business days," with a copy of the retail label.

And the agency gained a mandatory recall power. Where a cosmetic is adulterated or misbranded and use of it will cause serious adverse health consequences or death, the agency may order a recall if the responsible person will not do one voluntarily.

What safety substantiation does not mean

The safety duty is real, and it is easy to over-read. The agency is unusually direct about its limits.

A responsible person must ensure and maintain records supporting adequate safety substantiation of their products. Existing relevant safety data may be used.

Then comes the sentence to keep. "Neither the law nor FDA regulations require specific tests to demonstrate the safety of individual products or ingredients."

So substantiation is a records duty against a general standard, not a required protocol. The agency adds that data used to support safety should be derived from scientifically robust methods, and that animal testing is not a requirement for marketing.

The exemption list that tells you where the line is

Small businesses are exempt from some of the new duties, and the carve-outs from that exemption are the most informative list on the page.

The exemptions do not reach facilities making products that regularly contact the mucous membrane of the eye, or "Products that are injected." Nor do they reach products intended for internal use, or products meant to alter appearance for more than 24 hours where the consumer does not remove them.

Read the second item next to this market. An injected product is never inside the small-business exemption, and in the ordinary case an injected product is not being sold as a cosmetic at all.

The page also notes that exemptions exist for certain products and facilities subject to drug and device requirements, which is the seam where a product stops being only a cosmetic.

What to actually look at on a cosmetic peptide product

Four checks come straight out of the rules above, and all four are visible before you buy.

Look for the safety warning sentence. Its presence is a disclosure the regulation requires when safety was not adequately substantiated before marketing, and its absence is a statement in itself.

Read the ingredient list as an ordered list, because the order is required to be meaningful. A peptide near the end of a long declaration is present in a smaller proportion than one near the front.

Notice whether the list ends with the phrase covering exempted ingredients, and notice what the product claims. A claim to treat a condition is a drug claim, and it is the point at which a different rulebook, covered separately on this site, starts to apply.

Sources

Each document below is named as it names itself, with the date printed on that document rather than the day it was read.

1. Title 21 Code of Federal Regulations section 740.10, Labeling of cosmetic products for which adequate substantiation of safety has not been obtained — the duty to substantiate each ingredient and each finished product prior to marketing, the required principal display panel warning, and the three-part exception for a long-used ingredient — Electronic Code of Federal Regulations, Office of the Federal Register, March 1975
2. Title 21 Code of Federal Regulations section 740.1, Establishment of warning statements — the requirement that a cosmetic label bear a warning statement whenever necessary or appropriate to prevent a health hazard associated with the product — Electronic Code of Federal Regulations, Office of the Federal Register, March 1977
3. Title 21 Code of Federal Regulations section 701.3, Designation of ingredients — declaration in descending order of predominance, the fragrance and flavor exception, the prominence and letter-height requirements, the ordered sources for ingredient names, and the "and other ingredients" phrase for ingredients accepted as exempt from public disclosure — Electronic Code of Federal Regulations, Office of the Federal Register, March 1975
4. Modernization of Cosmetics Regulation Act of 2022 (MoCRA), the agency's own overview page, stating the facility registration and renewal cycle, product listing and annual updates, the safety substantiation records duty and that no specific tests are required, serious adverse event reporting within 15 business days, records access and mandatory recall authority, and the products excluded from the small business exemptions — U.S. Food and Drug Administration, August 2026