21st Century supplements, graded by the human studies
We graded 4 21st Century products against the human studies of their ingredients, the dose on each label and what buyers say in their reviews. Each grade belongs to the product and the goal it was graded for: we do not grade how 21st Century makes, tests or sells its products, and we sell no supplements. Educational, not medical advice.
The 21st Century products we graded
Members4 products, A to Z
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What 21st Century products were graded for
Each goal links to its page, with every product graded for it
| Goal | 21st Century products |
|---|---|
| Eye Health | 2 |
| Bone Health | 1 |
| Circulation | 1 |
Read more
Our articles on these goals
- Supplements for Focus and Mental ClarityArticle · Jun 16, 2026
- Peter Attia's Supplement List: What He Takes and What the Trials SayArticle · Sep 20, 2026
- Steven Gundry's Supplements, Reviewed: The Lectin Claim, the Gundry MD Line, What He Takes, and What the Evidence SupportsArticle · Oct 6, 2026
Questions people ask
Members
Is 21st Century a good brand?
Answer for members.
Which 21st Century products have the strongest evidence?
Answer for members.
How does Reverse Age Lab grade 21st Century products?
Answer for members.
Can I take 21st Century supplements with my meds?
Answer for members.
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Educational, not medical advice. Grades come from human studies on PubMed, the dose on each label, store reviews we read ourselves and our biohacker panel, and are updated as new studies arrive. 21st Century is a trademark of its owner; Reverse Age Lab is not affiliated with it and sells no supplements. How we grade →