Save the wording before investigating
Record the product name, seller, page address, date and complete claim. Include nearby pictures and qualifications: they can change the message a reader takes away. A label and an advertisement may say different things about the same bottle.
Identify the kind of claim
FDA’s label-claim guidance distinguishes health claims, nutrient-content claims and structure/function claims. These categories have different requirements. A structure/function statement about normal bodily function is not preapproved by FDA. Its required disclaimer does not show that FDA tested the product or confirmed a benefit.
A claim about a substance and reduced disease risk is different from a promise to treat a disease. Do not assume that a permitted claim about one substance justifies a broader statement about an entire supplement blend.
Ask what evidence matches the product
The FTC guidance explains that health advertising needs scientific support for its express and implied claims. Compare the product, dose, population and measured outcome in any cited study with what is actually being sold. An ingredient study or a customer story is not automatically evidence for the finished product.
Keep a record of what remains unknown
Write down the claim, the evidence offered and any mismatch. For example: “The seller links to an ingredient study; I have not found evidence testing this formulation for the advertised result.” That records a limit without pretending to deliver a clinical verdict. Discuss personal suitability with a qualified clinician or pharmacist before changing your supplement routine.