Iron Bisglycinate NSF (Thorne) Review 2026: Review
Checks out. — Legitimate
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"Chelated iron minimizes typical GI side effects"
Bisglycinate/Ferrochel forms are generally better tolerated than ferrous sulfate in comparative research.
Examine.com iron chelate research summary -
"NSF Certified for Sport claim on label"
NSF Certified for Sport is a real, verifiable third-party testing program checking for 200+ banned substances.
NSF Certified for Sport database -
"Product implies broad population may benefit"
Iron supplements only help people who test deficient; unnecessary use can disrupt gut bacteria and cause toxicity over time.
Internal: knowledge base iron risk profile -
"Price shown as 'N/A (MSRP)' with no public pricing"
You cannot compare cost to retail alternatives without creating an account, unlike most direct-to-consumer supplements.
Consumer advice
Don't take this (or any iron supplement) without a blood test confirming deficiency - excess iron isn't flushed out easily and can cause organ damage over time. The chelated (bisglycinate/Ferrochel) form is a legitimate choice if you do need iron, since it tends to cause less nausea and constipation than cheap ferrous sulfate. Since this is sold through Fullscript, a practitioner-dispensing platform, pricing isn't shown to the public - ask your provider for the actual cost, or compare to retail chelated iron products (typically $10-20 for 60-90 capsules) to make sure you're not overpaying. Keep it locked away from children regardless.
Claims vs Evidence
MODEST3 claims assessed. These grades assess the marketing claims, not the whole product. See each explanation for the evidence and its limits.
"Iron is essential to the formation and function of healthy red blood cells"
Supported
Well-established basic physiology, not controversial
Based on: Iron (Ferrochel bisglycinate)
"Optimal absorption / reduced GI side effects vs conventional iron"
Partial
Chelated forms are generally better tolerated, per knowledge base
Based on: Iron (Ferrochel bisglycinate)
"NSF Certified for Sport - tested for banned substances"
Supported
NSF certification is a verifiable third-party program
2 supported · 1 partial
Ingredients
Based on peer-reviewed research from PubMed and Examine.com
Why the chain breaks for this product
Most ingredients below have real research behind them. The problem isn't the ingredients — it's the doses. 3 of 4 are not disclosed on the label, so the product can claim the benefits without delivering the chain that gets you there.
Iron (as Ferrochel Ferrous Bisglycinate Chelate)
A highly absorbable chelated iron form. May correct iron deficiency with less stomach upset than standard iron.
Research-backed dose: 15-36 mg elemental iron daily (general adult RDA context; therapeutic doses vary)
In this product: 28 mg
Hypromellose Capsule
Encapsulated chili pepper extract. May modestly support fat breakdown, but weight loss evidence is limited.
Research-backed dose: 2-10 mg daily based on study doses
In this product: Dose not disclosed
Leucine
Building blocks your body can't make. Support muscle protein synthesis, especially in older adults.
Iron (Ferrochel bisglycinate)
Simple amino acid with early-stage evidence for blood sugar, heart, and metabolic support.
Safety & side effects
What NIH says about the ingredients in this product. This describes the ingredients, not tests of this product, and it is not medical advice. Ask a doctor or pharmacist first if you take medication, are pregnant or nursing, or have a health condition.
Iron
Iron from food carries little overload risk for adults with normal intestinal function, but high-dose supplements can cause gastrointestinal effects. Extremely high doses can be severe, and iron overdose is a leading cause of fatal poisoning in young children.
Possible side effects
- High-dose iron supplements can cause stomach upset, constipation, nausea, abdominal pain, vomiting, and diarrhea.
- Supplements with 25 mg iron or more can reduce zinc absorption and plasma zinc concentrations.
Serious risks
- Large acute intakes from supplements or medicines can lead to corrosive necrosis of the intestine, which might lead to fluid and blood loss, shock, tissue damage, and organ failure.
- In severe cases, iron overdoses can lead to multisystem organ failure, coma, convulsions, and even death.
- Case reports suggest some people develop more serious gastrointestinal effects, including gastritis and gastric lesions.
- At least 43 U.S. children died between 1983 and 2000 from ingesting high-dose iron supplements.
- Without treatment, people with hereditary hemochromatosis typically develop signs of iron toxicity by their 30s.
- Iron toxicity effects in hemochromatosis can include liver cirrhosis, hepatocellular carcinoma, heart disease, and impaired pancreatic function.
Avoid or ask a doctor first if
- People with hemochromatosis: treatment guidance includes avoiding iron and vitamin C supplements.
- The required FDA label on solid iron supplements says accidental overdose is a leading cause of fatal poisoning in children under 6, and to keep the product out of children's reach.
Medication interactions
- Iron supplements may interact with levodopa and levothyroxine.
- Proton pump inhibitors can potentially reduce iron absorption.
Upper limit: 45 mg a day for adults 19+. This label lists 28 mg.
Source: NIH Office of Dietary Supplements, Iron: Fact Sheet for Health Professionals
Research sources: PubMed · Examine.com
Analyzed product: https://fullscript.com/catalog/products/iron-bisglycinate-60-vegcaps
Analysis generated: 2026-07-05 · Engine v1.0.0
Frequently Asked Questions
Is Iron Bisglycinate NSF (Thorne) a scam?
Iron Bisglycinate NSF (Thorne) does not appear to be a scam. Our analysis found the claims are generally supported by the ingredients.
What are the ingredients in Iron Bisglycinate NSF (Thorne)?
Iron Bisglycinate NSF (Thorne) contains 4 ingredients including Iron (as Ferrochel Ferrous Bisglycinate Chelate), Hypromellose Capsule, Leucine, Iron (Ferrochel bisglycinate).
Does Iron Bisglycinate NSF (Thorne) actually work?
Yes, Iron Bisglycinate NSF (Thorne) can work for its intended purpose. 2 of 3 claims are fully supported. 1 are partially supported.
Does Iron Bisglycinate NSF (Thorne) have side effects?
NIH summaries of the ingredients in Iron Bisglycinate NSF (Thorne) note these possible effects. Iron: High-dose iron supplements can cause stomach upset, constipation, nausea, abdominal pain, vomiting, and diarrhea. This describes the ingredients, not tests of this product; ask a doctor or pharmacist.