Scores 35/35 for dosage transparency, 25/25 for a clean formula, 21/25 for label completeness. 5 ingredients disclosed with amounts.
softgel · 30 servings · $1.00/servingBuy on iHerb$30.00
Ranking
10 Best Antioxidant Supplements
Antioxidant and longevity supplements cover a wide range, from quercetin and grape seed extract to NMN and PQQ. Many of these ingredients come as standardized extracts, and the label is the only place to check the percentage of the active compound you are paying for.
We ranked quercetin, resveratrol, glutathione, grape seed, NMN, PQQ, carotenoids and other antioxidant products sold on iHerb by label quality.
Our top picks
Scores 35/35 for dosage transparency, 25/25 for a clean formula, 21/25 for label completeness. 4 ingredients disclosed with amounts.
capsule · 30 servings · $0.98/servingBuy on iHerb$29.34
Scores 35/35 for dosage transparency, 25/25 for a clean formula, 21/25 for label completeness. 5 ingredients disclosed with amounts.
capsule · 30 servings · $0.83/servingBuy on iHerb$24.95
Top 10 ranked
#ProductScoreFormServingsPrice
3
How we ranked them
Every product is scored 0–100 from its label data in the NIH Dietary Supplement Label Database: dosage transparency (35 points - are amounts stated per ingredient, or hidden in a proprietary blend?), label completeness (25), formulation cleanliness (25 - fillers, dyes, titanium dioxide and other non-active ingredients) and ingredient profile (15). The Top 10 admits only products scoring 60 or higher; among those, products with a verified retail listing are shown first so the list is one you can act on. No brand can pay to be included or moved up.
Forms and dosage
- Polyphenols (quercetin, resveratrol, grape seed)
- Standardized extracts state a percentage, such as 95% proanthocyanidins.
- Glutathione
- Reduced, liposomal or S-acetyl forms; oral absorption of plain glutathione is debated.
- NAD+ precursors (NMN, nicotinamide riboside)
- Newer ingredients with no established dose.
- Carotenoids (astaxanthin, lycopene)
- Measured in milligrams of the carotenoid itself.
How much to take
No official doses exist for most of these ingredients. Studies have used quercetin 500–1,000 mg, resveratrol 150–500 mg, and NMN 250–500 mg per day. Compare products by the amount of the active compound, not the total extract weight.
Who it's for
Adults who want a specific antioxidant at a disclosed, standardized dose.
What to watch out for
Extracts without standardization, "antioxidant blends" with no amounts, and beta-carotene supplements if you smoke (higher lung cancer risk in trials).
All Antioxidants & Longevity products (3615)
1
Life Extension GeroprotectAgeless Cell
892Nature's AnswerResveratrol
893NutraChampsResveratrol
894Pure SynergyCell Protector
895Natural FactorsBioactive Querctin EMIQ 50 mg
886EnzymedicaTelomere Plus
887Natural FactorsBioactive Quercetin EMIQ
888Natural FactorsCherryRich Super Strength Cherry Concentrate 36:1 500 mg
889Natural Factors100% Natural BetaCareAll Mixed Carotenoid Complex 25,000 IU
8810ThorneBroccoli Seed Extract
8711NOWGreen Tea Extract 400 mg
8612Swanson UltraDr. Stephen Langer's Glutathione Precursor Complex
8613SMNutritionActivated Sulforaphane Complex
8614DaVinci Benefits LinePhyto Benefits
8615NOWGrape Seed
8616SwansonGlutathione Precursor Complex
8617NOWCitrus Bioflavonoids With Ascorbic Acid And Rutin
8518BiotiviaTransmax Tr
8519NOWCitrus Bioflavonoids
8520Doctor's BestBest Stabilized R-Lipoic Acid
85Frequently Asked Questions
What does standardized extract mean?
The extract is guaranteed to contain a stated percentage of an active compound. Without it, two products with the same milligram amount can differ a lot.
Is NMN worth it?
Human research is early. Our ranking judges how clearly the label states what you get.
How are antioxidants & longevity supplements ranked?
Products are ranked by SupplementScore, which evaluates label quality across four categories: dosage transparency (35 pts), label completeness (25 pts), formulation cleanliness (25 pts), and ingredient profile (15 pts). The score is based on data from the NIH Dietary Supplement Label Database, not marketing claims.
Does a higher score mean the supplement is more effective?
No. The SupplementScore measures label quality, how transparent, clean, and well-documented a product is. It does not measure clinical efficacy, bioavailability, or third-party testing. A higher score means better label practices, not guaranteed results.
How many antioxidants & longevity supplements were analyzed?
We analyzed 3,615 antioxidants & longevity products from the NIH DSLD database, which contains label data for over 116,000 dietary supplements sold in the United States.
This article is for information only and is not medical advice. Talk to a clinician before starting a supplement, especially if you are pregnant, take medication or have a health condition.