THORNE - Iron Bisglycinate - 25 mg Iron Supplement for Enhanced Absorption Without…
- Iron
- Capsule
- Iron
- 60
- Better rated than 56%
- More reviewed than 83%
A sport-certified iron bisglycinate at a moderate 25 mg dose, built for tested athletes and anyone who reacts poorly to standard iron supplements.
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How it ranks among the 59 iron we track
4.7★ across 8,388 Amazon ratings, Bayesian-smoothed toward the category average.
8,388 Amazon ratings, weighted on a log scale so huge counts don't drown everything.
40,000+ bought on Amazon last month.
Brand identity, imagery, description and spec coverage.
The ProductDome score is separate from the Amazon rating shown above: it combines the Bayesian-smoothed Amazon rating with evidence volume, tracked demand, and data quality across the 59 iron we track - how the scorecard works · full iron data report. Confidence: medium - useful but incomplete evidence.Last refreshed Aug 4, 2026. Data-computed, not a hands-on test. Compiled by the ProductDome Research Team.
Overview
Thorne Iron Bisglycinate delivers 25 mg of iron per serving in a bisglycinate form, chosen for easier absorption with less gastrointestinal irritation than standard iron salts, in a 60-serving, vegetarian, dairy, gluten and soy-free capsule that carries NSF Certified for Sport status.
Iron bisglycinate is a chelated form that is generally better tolerated than ferrous sulfate, which is the reasoning behind Thorne's enhanced-absorption claim in the title, though it is a formulation choice rather than a result from independent lab testing in this listing. The NSF Certified for Sport mark matters specifically to competitive athletes, since it screens for banned substances, a step not every supplement brand takes. At 25 mg per serving, the dose sits below the higher-strength iron products aimed at diagnosed deficiency.
- 25 mg iron bisglycinate per serving
- NSF Certified for Sport
- 60 servings per bottle
- Dairy, gluten and soy free, vegetarian
Who it's for
Fits athletes who need a sport-certified iron supplement clear of banned substances, and anyone who has had stomach trouble on standard iron tablets and wants a gentler chelated form. Not the pick for someone who has been told by a doctor to take a higher iron dose than 25 mg.
Strengths and trade-offs
Drawn from this product's published specifications.
- NSF Certified for Sport, screened for banned substances
- Bisglycinate form chosen for easier absorption and tolerance
- Dairy, gluten and soy free, vegetarian formula
- Lower 25 mg dose than some deficiency-focused iron products
- Not a substitute for a doctor-prescribed higher dose
Performance notes
Iron bisglycinate binds the mineral to glycine, a structure generally associated with easier absorption and less gut irritation than ferrous sulfate or ferrous fumarate. The NSF Certified for Sport status means each batch is screened for substances banned in competitive sport, relevant mainly to tested athletes. At 60 servings and 25 mg per serving, the bottle covers roughly two months at a once-daily dose.
Specifications
| Brand | THORNE |
|---|---|
| Model | M226 |
| Form | Capsule |
| Supplement Type | Iron |
| Count | 60 |
| Benefits | Sports Performance |
| Flavor | Unflavored |
| Diet | Vegetarian |
| Allergens | Dairy Free, Gluten Free, Soy Free |
Other THORNE iron
How it compares
This product against the closest alternatives we track in iron.
| Product | Amazon rating | Ratings | ProductDome score |
|---|---|---|---|
| THORNE - Iron Bisglycinate - 25 mg Iron Supplement for Enhanced Absorption Without…This product | 4.7 / 5 | 8,388 | 4.5 / 5 |
| Nature Made Iron 65 mgNATURE | 4.7 / 5 | 54,615 | 4.6 / 5 |
| Nature's Bounty Iron 65mgNature’s | 4.7 / 5 | 35,600 | 4.6 / 5 |
| Slow Fe 45mg Iron Supplement for Iron DeficiencySlow | 4.7 / 5 | 9,942 | 4.6 / 5 |
| Feosol Original Iron Supplement TabletsFeosol | 4.7 / 5 | 9,100 | 4.6 / 5 |
Similar iron from other brands
Questions about the THORNE M226
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
What form of iron is used in Thorne Iron Bisglycinate?
It uses iron bisglycinate, a chelated form generally associated with easier absorption and less stomach irritation.
Is Thorne Iron Bisglycinate certified for athletes?
Yes, it carries NSF Certified for Sport status, meaning it is screened for banned substances.
How many servings are in a bottle of Thorne Iron Bisglycinate?
One bottle provides 60 servings at 25 mg of iron each.