In short: we judge a supplement on four things: whether its ingredients work at the doses it contains, how safe and transparent it is, how its quality is assured, and what it costs per serving. Brands can’t pay for a review or a better score.
Last updated: October 19, 2026
What we look at
For every product we review, we check:
- The full label: every ingredient, the amount per serving, and any proprietary blends that hide individual doses.
- The research on each ingredient: whether human studies support it, and whether the product contains the dose those studies used.
- Safety: known side effects, drug interactions, label warnings, and any FDA warning letters or recalls we can find.
- Quality: who makes it, and whether it carries an independent certification such as NSF Certified, USP Verified or Informed Sport.
- Price and terms: cost per serving, subscription or auto-ship terms, and the refund policy.
How we score
When a review shows a score, it comes from this method:
| Factor | Weight | What earns a high score |
|---|---|---|
| Evidence at the doses used | 35% | Ingredients backed by human research, at research-level doses |
| Safety and transparency | 25% | Full label, clear warnings, no hidden blends |
| Quality assurance | 20% | Independent third-party testing, known manufacturer |
| Value | 20% | Fair price per serving compared with similar products |
Each factor is scored out of 10 and weighted. If key facts are missing, such as hidden doses or no testing information, the score is capped at 6 out of 10 and the review explains why.
Research reviews and hands-on reviews
Most of our reviews are research reviews: we study the label, the published research on each ingredient and the brand’s own claims. Each review says clearly at the top whether we have used the product ourselves. We never claim to have tested something we haven’t.
What we never do
- Accept payment for a review, a higher score or a place in a list.
- Let a brand approve or edit a review before it’s published.
- Invent customer reviews, star ratings or testimonials.
- Repeat a brand’s disease claims or call a product “clinically proven” unless that exact product has been tested in a published trial.
- Hide subscription terms or the negatives we find.
Affiliate links
We may earn a commission if you buy through links in a review. Commissions are the same whatever score a product gets, and products without an affiliate program are reviewed the same way. See our affiliate disclosure.
Something out of date?
Formulas, prices and terms change. If a review no longer matches the product you see, please tell us through our contact page and we’ll check it.