How We Evaluate Products and Suppliers

Our product and supplier reviews answer a narrow question: what does the maker publish, and how much of it could we confirm? This page explains the method, what each label on a review means, and what we deliberately do not do.

A documentation review, not a lab test

Every review states its method at the top. All of our reviews so far are documentation reviews: a "How this was evaluated" box, marked "No product sample analyzed," lists the documents we checked and says that we did not independently analyze a product sample.

In practice, that means we read the product label and ingredient list, the product page, any testing documents the maker links to, and the seller's returns, shipping and support policies. We record what each one says, whether we could confirm it, and the date we checked.

A second label, Independent analysis, is reserved for a review in which a sample was actually sent to a named laboratory and the report is linked. We have not published any review of that kind. We never describe a documentation review as hands-on testing.

What we check on a finished product

The label and ingredient list

For cosmetics, US rules require ingredients to be listed in descending order of predominance, under names established or adopted by regulation ^{Source [1]}, but they do not require concentrations to be stated ^{Source [2]}. Those standardized names are INCI names ^{Source [3]}. We record whether the peptide is named, where it falls in the list, and whether the maker states a concentration anywhere.

For dietary supplements, the label must carry a Supplement Facts panel and the name and place of business of the manufacturer, packer or distributor, and any structure or function claim must come with the FDA's standard disclaimer ^{Source [4]}. We record what the panel states per serving and whether the source of the main ingredient is named.

Claims against evidence

The Federal Trade Commission's guidance for health products says health claims need competent and reliable scientific evidence, and asks how the dosage and formulation of an advertised product compare with the product used in the research ^{Source [5]}. We apply the same test. For each claim a maker publishes, we look for evidence on that form and route: a study of an oral supplement does not support a cream, and a study of one formula does not automatically support another. Where a claim rests on evidence from a different form, the review says so. How to Read a Peptide Study explains the questions we ask.

Testing documents

When a maker links a certificate of analysis or a test report, we note who issued it, which product and batch it covers, what it measured and when. "Certificate linked" and "issuing lab confirmed" are separate findings: a link shows that a document exists, and confirmation means we could check it with the issuer. A laboratory's accreditation covers the activities defined in its scope of accreditation, which can be checked in the accreditation body's online directory ^{Source [6]}. For certification seals, we look the product up in the program's own directory. See What a Certificate of Analysis Can and Cannot Tell You and Third-Party Tested.

Price and policies

We record the price and the date we saw it, whether the seller ships to the United States, how returns work and how to reach support. Prices and policies change often, so each one carries its own check date.

What we check on a supplier

When the subject of a review is a supplier rather than a single product, we also check:

• that the website is the supplier's official domain, and what business information it publishes (How to Check a Supplier's Official Domain);
• returns, support and shipping to the market a reader is in;
• whether testing documents match the batch and product being sold, and whether the issuing laboratory could be confirmed;
• how current the documents are.

A clean set of documents describes one batch. It does not show that a product works, is sterile, or is suitable for personal use.

How findings are shown

• Findings are marked Confirmed, Partly confirmed or Not confirmed, with a short note explaining why.
• Criteria use three marks: ● met, ◐ partly met, ○ not met or not provided. "Not provided" means the maker does not publish that information. It is not a score of zero, and it is not the same as a failed test.
• Comparisons apply the same criteria to every product, and mark missing information as "Not provided" and things that do not apply with a dash. There is no overall winner, because the right choice depends on which criteria matter to you.

We do not give star ratings, overall scores or rankings.

What we do not do

• We do not test samples, measure outcomes, or describe products as tested by us.
• We do not give dosing guidance, protocols or personal medical advice, and we do not say whether a product is right for you.
• We do not review research materials as products for people to use.
• We do not accept payment for a review, a rating or a position on a page.

Money and relationships

Today we have no commercial relationship with any product or supplier we cover. There are no affiliate commissions, sponsorships or paid placements, and our links to products go to official websites without any payment to us. Each review shows its commercial relationship in a box at the top, which today reads "No commercial relationship."

If that changes, the relationship will be disclosed on every affected page before the first paid link, and each paid link will be labeled where it appears. This follows the FTC's guidance that a paid relationship should be disclosed clearly and close to the recommendation; the FTC says "paid link" right next to an affiliate link should be an adequate disclosure ^{Source [7]}. A commission would never change findings, criteria, or the order of products, and options that pay us nothing would stay in. Our affiliate disclosure sets out the details.

How reviews are kept current

Every review shows the date it was last checked and keeps a dated update log. Reviews in our Skin & Topical and Collagen & Nutrition categories are scheduled for a re-check at least every 90 days, and sooner if we learn that a formula, label or policy has changed. If a product or supplier link needs to be re-checked, we pause it and explain why instead of sending readers to a page we have not verified.

If you think a finding is wrong, tell us. Material corrections are made on the page and recorded in its update log. Our methodology explains how we rate evidence, and the corrections page explains how reports are handled.