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Thorne Iron Bisglycinate vs Pure Encapsulations Iron-C (2026)
Disclosure: We earn commissions on purchases made through our links. This never influences our scores. Editorial policy
The Verdict
Thorne (A overall) slightly outscores Pure Encapsulations (A- overall) with a better value score. Pure Encapsulations' inclusion of vitamin C is a genuine formulation advantage for absorption, but you can achieve the same benefit by taking Thorne's iron with a glass of orange juice. Both are excellent gentle-iron options. Thorne is the better value; Pure Encapsulations is more convenient if you want the vitamin C built in.
Thorne Iron Bisglycinate
Thorne
Pure Encapsulations Iron-C
Pure Encapsulations
Head-to-Head Comparison
| Category | Thorne Iron Bisglycinate Thorne | Pure Encapsulations Iron-C Pure Encapsulations |
|---|---|---|
| Overall | A | A- |
| Evidence | A | A |
| Quality & Purity | A+ | A |
| Value | B | B- |
| Transparency | A | A+ |
| Cost/Day | $0.33Winner | $0.44 |
| Dose/Serving | 25mg | 25mg |
| Form | ferrous bisglycinate chelate capsule | iron bisglycinate + 100mg ascorbic acid, hypoallergenic capsule |
| Third-Party Tested | ✓ Yes | ✓ Yes |
| Proprietary Blend | No | No |
Why This Comparison Matters
Iron supplementation is notoriously difficult because most forms cause GI distress - nausea, constipation, and stomach pain. Both Thorne and Pure Encapsulations address this with bisglycinate chelate, a form shown to cause significantly fewer side effects than ferrous sulfate while maintaining good absorption.
Pure Encapsulations adds vitamin C to its formulation, which research shows enhances non-heme iron absorption by 2-3x. Thorne offers the bisglycinate alone, allowing you to control vitamin C intake separately.
We compare both on our four-factor scoring system, with particular attention to the vitamin C co-factor question.
Detailed Score Breakdown
Thorne Iron Bisglycinate
Thorne
25mg elemental iron as ferrous bisglycinate chelate - a well-studied chelated form with strong clinical evidence for efficacy and tolerability
NSF Certified for Sport - verified free of 270+ banned substances and tested for label accuracy. Thorne manufacturing exceeds FDA cGMP standards. The gold-standard certification in the supplement industry.
$0.33/day at 25mg (one capsule). At a therapeutic dose of 50mg, cost is $0.66/day. Premium pricing is justified by NSF Certified for Sport status.
Fully disclosed label. Iron form specified as bisglycinate chelate. No proprietary blends. Minimal excipients. NSF certification seal displayed.
NSF Certified for Sport makes this the top choice for competitive athletes and anyone prioritizing certification rigor. Clean capsule with minimal excipients.
Pure Encapsulations Iron-C
Pure Encapsulations
25mg iron bisglycinate combined with 100mg vitamin C per capsule - the vitamin C co-formulation directly supports non-heme iron absorption through a well-established mechanism
Third-party tested by Eurofins. Hypoallergenic formula - free from gluten, dairy, soy, eggs, tree nuts, peanuts, and artificial additives. Practitioners frequently recommend Pure Encapsulations for sensitive patients.
$0.44/day at 25mg. The built-in vitamin C adds some value over buying separately, though it slightly increases per-capsule cost.
Exemplary transparency. Every ingredient fully disclosed with amounts. Iron form specified. Vitamin C as ascorbic acid clearly labeled. No fillers, binders, or coating agents beyond the capsule shell.
Built-in vitamin C is a meaningful practical advantage. The go-to option for people with food allergies or multiple sensitivities. Practitioner-grade quality.
How We Compared These Products
Every product in our database is scored on four equally-weighted categories: clinical evidence quality, third-party testing and purity verification, cost per clinically effective dose (not cost per pill), and label transparency. These scores combine into an overall letter grade from A+ through F.
Cost per effective dose is calculated using the clinically studied dose from published research, not the manufacturer's suggested serving. If a product requires multiple servings to reach the dose used in clinical trials, that cost is reflected in the value score.
For a full explanation of our scoring methodology, see our methodology page. Prices were last checked on the dates listed for each product and may have changed.
More Iron (Bisglycinate) Comparisons
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FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products discussed on this page are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.