How we rate supplements

We start from published human studies, then compare product labels with what those studies used.

How we pick studies

We search PubMed for meta-analyses, systematic reviews, and randomized trials in people. We also include results that found no benefit and reports of harm. Every claim links to its PubMed record. Summaries are based on study abstracts.

What the evidence grades mean

• Strong proof: several good trials or a meta-analysis with consistent results.
• Some proof: positive results, but trials are small, uneven, or limited to certain groups.
• Little proof: few human trials, mixed results, or no clear benefit.

How we rank products

1. Is the label close to the dose used in studies?
2. Is it the form used in studies?
3. Does it avoid unrelated added ingredients?
4. Does the label state the active amount clearly?
5. How many customers have reviewed it?

We compare labels. We do not test products in a lab, so we cannot confirm that a product contains what its label states. If few products fit, we list fewer.

Affiliate disclosure

Dose by Study earns money through affiliate links to iHerb. If you buy through a link, we may earn a commission at no extra cost to you. Payment does not change our evidence grades.

Medical disclaimer

Dose by Study provides general information and does not diagnose, treat, or give medical advice. Ask your doctor or pharmacist before starting a supplement.