Our Methodology

How we evaluate resveratrol supplements. This page explains exactly what we score on, what weight each factor carries, and — importantly — what we do not do.

We are not a testing lab. We do not run our own assays on third-party products. We evaluate vendor documentation, published Certificates of Analysis, label transparency, and price per active milligram. When a product is described as "third-party tested," we are reporting what the manufacturer publishes — not testing it ourselves. We are also not doctors; nothing on this site is medical advice.

Scoring rubric (100 points)

Purity & label transparency30%
Third-party testing & COA availability25%
Value (price per active mg)20%
Vendor reliability & shipping15%
Formulation & absorption support10%

How we score each factor

1. Purity & label transparency (30%)

We prefer products that disclose percentage of trans-resveratrol (the bioactive form), not just total resveratrol. Products with a stated trans-resveratrol percentage of 98%+ score higher. Proprietary blends that hide ingredient amounts score lower.

2. Third-party testing & COA availability (25%)

We check whether the brand publishes a Certificate of Analysis from an independent lab. A COA that anyone can look up scores highest; "we test in-house" claims with no public documentation score lower.

3. Value — price per active milligram (20%)

We compute price per mg of trans-resveratrol, not price per capsule. A cheap-per-capsule product with 50% purity is worse value than a premium product at 98% purity.

4. Vendor reliability & shipping (15%)

We look at how long the brand has been operating, whether they have a clear contact address, customer-service responsiveness, and return policy.

5. Formulation & absorption support (10%)

Bonus points for liposomal delivery, BioPerine, or other absorption enhancers backed by published research. We do not award points for marketing language alone.

What disqualifies a product

When and how we update reviews

Every review carries a "Published" and "Last updated" date. We re-check pricing and stock at minimum quarterly, and re-score whenever a brand reformulates or changes its testing policy. If we materially change a ranking, we note what changed and why.

Independence and conflicts of interest

We earn affiliate commissions when readers buy through our links. Commission rate does not affect ranking position. We have refused commissions from brands we won't recommend, and we have ranked products that pay us nothing above products that pay us more. See our editorial policy for the full firewall.

Last updated: 2026-05-15