Supplement pages are built to persuade, and the strongest-sounding claims are often the weakest-supported. This checklist draws on guidance from US government sources and applies it to a real example. It is general information, not medical advice.
1. Know what regulation does and does not cover
The FDA says it does not have the authority to approve dietary supplements before they are marketed, and that manufacturers and distributors have the initial responsibility for ensuring their products meet safety standards. That means a product being on sale is not evidence that it works or has been reviewed for your situation.
2. Read the label, not the headline
The FDA advises consumers to read the label of any supplement carefully. Look for the Supplement Facts panel, the amount of each active ingredient per serving, the serving size and any warnings. If a page names ingredients but gives no amounts, you cannot compare it with the doses used in any study.
3. Separate ingredient studies from proof for the product
The FTC lists red flags in health claims: one product said to help many unrelated conditions, fake or unverifiable testimonials, and scientific-sounding language such as “clinically proven” that proves nothing by itself. A study of one ingredient, at one dose, in one patient group does not show that a different product with a different formula works. Check whether the study tested the finished product, who funded it and how many people took part.
4. Check the guarantee and the subscription terms
The FTC also warns that offers such as “results in 30 days or your money back” are often empty. Read who is covered (first order only, or every order), whether renewals and trial conversions are excluded, how you cancel and when it is too late to stop a shipment. Take a screenshot of the price and terms at checkout.
5. Talk to a professional, and know how to report a problem
The FDA advises talking to your doctor, pharmacist or other health care professional before taking a supplement, since some can interact with medicines. If you have a bad reaction, it says to contact or see your health care provider first, and you or your provider can then report it to FDA.
An example: checking a supplement against the list
In our Strong Cell review we applied these questions to a liquid NADH, CoQ10 and collagen product. Its references page lists ten references that concern ingredients, not the finished product. The oral NADH research we found is small: a 1999 pilot trial of 26 chronic fatigue syndrome patients reported 8 responders on NADH versus 2 on placebo, and a larger 2010 trial of 77 completers found no significant differences in most measures. RxList rates NADH for chronic fatigue syndrome as having insufficient evidence to rate. The brand does offer a 90-day first-order guarantee, but recurring subscription charges are excluded from it, which is the kind of detail step 4 is meant to catch.
A note on the sources
The FDA and FTC pages are US consumer guidance and apply to the US market; rules differ elsewhere. RxList summarizes a commercial natural-medicines database. The PubMed abstracts describe small studies and do not cover every NADH product or dose. We wrote this article in our own words and did not copy text. Some links to brands on this site are affiliate links; see our affiliate disclosure.