How to choose a quality supplement

The supplement industry is large, competitive, and — compared with prescription drugs — lightly regulated. In the United States, supplements don't need FDA approval before they're sold. The FDA can act against a product after the fact, but the burden is largely on manufacturers to police themselves. That means quality varies enormously from one bottle to the next, and the label doesn't always match what's inside.

The good news: a few habits will steer you toward the small share of products actually worth taking.

Look for third-party testing

Independent testing is the single most useful signal of quality. Organizations like NSF International, USP, and Informed Choice test products for what's actually on the label and screen for contaminants and banned substances. A seal from one of these means someone other than the manufacturer has verified the contents. (We cover this in its own article.)

Check the form, not just the ingredient

Two products can list the same ingredient and behave very differently. Magnesium oxide is poorly absorbed and can loosen the bowels; magnesium glycinate is gentler and better absorbed. For some people, folate is a better choice than folic acid. The specific form often matters more than the headline ingredient, so it's worth knowing which form is best studied for your goal.

Be wary of proprietary blends

A 'proprietary blend' lets a company list several ingredients under one total weight without telling you how much of each is inside. That's convenient for the manufacturer and unhelpful for you — a blend can be mostly a cheap filler with a sprinkle of the active ingredient. Products that disclose the exact amount of every ingredient are being straight with you.

Match the dose to the research

Effective ingredients still have to be dosed like the studies that support them. A product can contain a legitimate ingredient at a fraction of the researched amount — impressive on the label, and close to useless in practice. When we recommend a supplement, we point to the dose the evidence actually used.

Ignore the hype words

'Clinically proven,' 'doctor formulated,' 'natural,' and 'detox' are marketing terms with no legal definition. They tell you nothing about quality. Let the testing seal, the ingredient forms, and the transparency of the label do the talking instead.

The short version

Choose products that are third-party tested, use well-absorbed forms at researched doses, disclose every ingredient amount, and skip the ones leaning on buzzwords. That's most of what separates a supplement worth your money from one that isn't — and it's why we vet the products we recommend rather than leaving you to guess.