Size: 60 capsules
Thorne's Iron Bisglycinate delivers 25 mg of elemental iron in chelated bisglycinate form — a highly absorbable, gentle-on-the-stomach format that supports healthy red blood cell production, oxygen transport, and energy metabolism. It's well-suited for individuals with increased iron needs, including women of reproductive age, athletes, or those with dietary gaps.
Why It's Worth Considering: The bisglycinate chelate is designed to reduce the GI discomfort commonly associated with iron supplementation, and this formula carries NSF Certified for Sport® verification — a meaningful credential for competitive athletes subject to testing.
| Feature | Bisglycinate (gentle) | Ferrous Sulfate | Ferrous Fumarate | Heme Iron |
|---|---|---|---|---|
| Absorption | High (chelated) | Moderate | Moderate | Highest (animal-derived) |
| GI Side Effects | Minimal | Common (constipation) | Moderate | Minimal |
| Best For | Sensitive stomachs | Budget, proven | Higher elemental iron | Maximum absorption |
| Take With | Empty stomach OK | Vitamin C required | Vitamin C helps | Anytime |
Iron bisglycinate (Ferrochel) is the best-tolerated form with high absorption and minimal GI side effects. Ferrous sulfate is the most studied but commonly causes constipation and nausea. Heme iron polypeptide has the highest absorption rate but is animal-derived.
Non-chelated iron forms (ferrous sulfate, fumarate) are poorly absorbed — the unabsorbed iron irritates the gut lining and slows peristalsis. Chelated forms (bisglycinate) are absorbed more completely, leaving less unabsorbed iron in the gut. Taking vitamin C improves absorption and reduces GI side effects.
Separate iron from calcium, zinc, magnesium, and dairy by 2+ hours (they compete for absorption). Separate from thyroid medication by 4+ hours. DO take iron WITH vitamin C (doubles absorption). Avoid taking with coffee or tea (tannins reduce absorption by 60%).
Get a complete iron panel: serum ferritin (most sensitive — optimal is 50-100 ng/mL), serum iron, TIBC, and transferrin saturation. Symptoms of deficiency: fatigue, cold hands/feet, pale skin, brittle nails, shortness of breath, brain fog, and restless legs. Ferritin below 30 ng/mL warrants supplementation in most cases.
† 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.
