Supplement Red Flags

Not every supplement is a scam. But plenty of them are. Here are the warning signs that should make you think twice before buying.

Proprietary blends. If a label says “proprietary blend” and lists ingredients without individual doses, that’s a problem. You have no idea how much of each ingredient you’re getting. Companies hide behind proprietary blends when the doses are too low to actually work. Good brands list every ingredient with an exact amount.

No third-party testing. Any reputable supplement should be tested by an independent lab like NSF, USP, or Informed Sport. Third-party testing confirms the product actually contains what the label says and isn’t contaminated with heavy metals or other junk. If a brand doesn’t have third-party testing, ask yourself why.

Celebrity endorsements as evidence. A famous athlete or influencer holding up a bottle isn’t evidence. They got paid to do that. Testimonials and endorsements tell you nothing about whether a supplement works. Only controlled trials can do that. If the marketing leads with a celebrity and buries (or skips) the research, be skeptical.

Too-good-to-be-true claims. “Lose 30 pounds in 30 days!” “Reverse aging!” “Cure your chronic disease!” If it sounds like a miracle, it isn’t one. Real supplements have modest effects at best. Any product promising dramatic, life-changing results is selling you a fantasy.

“Ancient secret” marketing. “Used for 5,000 years in traditional medicine!” This isn’t evidence. Plenty of ancient remedies don’t hold up under modern testing. Some do, and we rate those fairly when the RCTs support them. But tradition alone isn’t proof that something works. The question is always: what do the controlled trials show?

If you spot two or more of these red flags on a single product, you’re probably looking at snake oil. For a deeper look at how we evaluate supplements, read How We Rate.