Guide
How to choose a good resveratrol
A good resveratrol label says how many milligrams are trans-resveratrol, not just how much extract. We run our own capsule against the same eight checks, including where it falls short.
A good resveratrol supplement tells you how many milligrams are trans-resveratrol, not just how much extract is in the capsule. A "600 mg" label can mean 600 mg of extract or 600 mg of resveratrol, and those differ by up to a factor of two. Here are eight checks, with our own capsule held to them.
1. Complex weight vs trans-resveratrol
This is the check that matters most. Many labels print the weight of a root extract ("complex") and a percentage. Multiply them.
| Label | Arithmetic | Trans-resveratrol |
|---|---|---|
| 600 mg complex containing 50% trans-resveratrol (ours) | 600 x 0.50 | About 300 mg per capsule |
| 1,800 mg complex, 50% trans, per 3 capsules | 1,800 x 0.50 | About 900 mg per serving |
| "500 mg resveratrol", no percentage | Unknown | Ask the seller, or move on |
Ours: the 600 mg is the complex. The label's 50% gives about 300 mg of trans-resveratrol a capsule, about 600 mg a day at two capsules. That is arithmetic from the label, not a measured value, and the panel does not say what the other half of the complex is.
2. The form
Look for "trans-resveratrol" and the source. Ours is a root extract from Japanese knotweed (Polygonum cuspidatum). A "red wine extract" or "resveratrol blend" with no percentage tells you little.
3. The dose against the trials
Trials have used 25 mg (an absorption study), 75, 150 and 200 mg a day, 1 g a day and 0.5 to 5 g a day. None we could verify matches 600 mg a day of trans-resveratrol, so we do not say what our capsule does. What the trials found is on the research page. Be wary of any label whose dose is justified by a trial at a different dose or form.
4. Absorption claims
Resveratrol is poorly retained in blood. In a six-person study, at least 70% of a 25 mg oral dose was absorbed, but only trace amounts of unchanged resveratrol (under 5 ng/ml) appeared in plasma. A "liposomal", "micronised" or "enhanced absorption" claim is worth believing only if it comes with human data on that product. We have not verified any, and we make no such claim for ours.
5. What else is in the capsule
Read "Other ingredients". Ours lists hypromellose (a vegetable capsule) and microcrystalline cellulose, which is a common bulking ingredient. Nothing else is listed. Be sceptical of "no fillers" as a slogan, because it means different things to different makers.
6. Testing
A certificate of analysis for the batch is what turns "50% trans" from a label statement into a measured number. We have no certificate of analysis on file for ours, so we do not claim third-party testing, and the 50% is the label's statement. Look for a batch-specific certificate or an independent certification mark, and ask the seller for it.
7. Price per day and per milligram
Bottle price hides serving size. Ours is as low as $15.83 a bottle on subscription for 60 capsules; at two capsules a day that is about $0.53 a day, or about $0.09 per 100 mg of trans-resveratrol by the label's 50% (our arithmetic). Compare other products the same way: price per day divided by trans-resveratrol milligrams per day, using the seller's own price on its own site.
8. Who it is not for
Check the warning line. If you take prescription medication or have a health condition, read resveratrol and medications and who should not take resveratrol, and ask a doctor.
Where we fall short
- No certificate of analysis on file, so no third-party-testing claim.
- The 50% trans-resveratrol figure is the label's, and half the complex is unidentified on the panel.
- No human trial matches our dose, so no benefit statement.
You can see the label on the product page.
Questions people ask
Which resveratrol supplement should I choose?
The one that clearly states trans-resveratrol per serving, shows testing and fits your budget per day. We do not rank by reviews, and we cite none.
Which form of resveratrol is better to take?
We cannot say one form is better; no verified head-to-head human trial of forms exists in what we read. Prefer labels that name trans-resveratrol.
Where can you buy resveratrol?
From a seller that prints the full Supplement Facts panel and can provide batch testing. Check the panel before you buy, wherever you shop.
Where can you find resveratrol naturally, and what food is highest?
Red wine is the food we can quantify: a survey of one Spanish variety measured about 19 mg per litre on average and about 30 mg per litre at the top, so a glass holds a few milligrams, well below a capsule. We have not verified figures for other foods.
What is a typical price range?
We have not surveyed the market for this guide, so we give no range. Use the per-day, per-100 mg method above.
Are top-rated or "heart health" resveratrol products better?
Star ratings and health-themed marketing are not evidence about what is in the capsule. Check the panel and the dose instead.
Sources
- High absorption but very low bioavailability of oral resveratrol in humans Most of a 25 mg dose was absorbed, but almost none stayed in the blood as plain resveratrol; it was converted to other compounds.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
