Home Ingredients Heme Iron Polypeptide (HIP)
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Heme Iron Polypeptide (HIP)

Evidence Level
Moderate
2 Clinical Trials
5 Documented Benefits
3/5 Evidence Score

Heme iron polypeptide (HIP, brand: Proferrin) is iron derived from animal hemoglobin — bound within a protein matrix exactly as iron exists in red meat. Distinguished by fundamentally different absorption pathway from non-heme (ferrous salt) iron — uses heme transporter HCP1, not DMT1. Up to 21% absorbed (vs ~0.1% for ferrous gluconate when taken with meals). Much fewer GI side effects but expensive and animal-derived (not vegetarian/vegan).

Studied Dose 10-22 mg elemental heme iron/day; Proferrin Forte = 11 mg elemental iron per tablet
Active Compound Heme iron polypeptide (porcine or bovine hemoglobin-derived)

Benefits

Distinct Absorption Pathway (HCP1)

Heme iron uses the HCP1 (heme carrier protein 1) transporter — different from non-heme iron's DMT1 pathway. Means heme iron absorption is not affected by phytates, polyphenols, calcium, or PPI use. Reliable absorption with meals.

Supported by Trial 1

Up to 21% Absorption Rate

Heme iron polypeptide absorbed at ~21% efficiency vs ~0.1-2% for ferrous gluconate when taken with meals. Even compared to fasting ferrous sulfate (~10-15%), heme iron is substantially better-absorbed when timing is convenient (with meals).

Supported by Trial 1

Minimal GI Side Effects

Heme iron polypeptide causes substantially fewer GI symptoms than ferrous salts — less constipation, less nausea, less metallic taste. Bound iron means no free Fe²⁺ irritating mucosa.

Supported by Trial 1, Trial 2

No Drug Interaction with Calcium/PPIs

Unlike ferrous salts, heme iron absorption is not meaningfully reduced by calcium, PPIs, antacids, coffee, or tea. Patients on chronic acid suppression (very common) maintain iron absorption.

Supported by Trial 1, Trial 2

IBD/Crohn's/Bariatric Surgery Patients

Heme iron may be preferred form for IBD patients (gentler), bariatric surgery patients (altered iron absorption pathways), and chronic PPI users — populations where ferrous salt absorption is problematic.

Supported by Trial 1

Mechanism of action

1

HCP1 (Heme Carrier Protein 1) Transport

Heme iron is absorbed intact via HCP1 transporter on duodenal enterocyte apical membrane. Inside the cell, heme oxygenase releases iron from the porphyrin ring; the iron is then exported via ferroportin like other iron sources.

2

Bypass of Iron Absorption Inhibitors

Phytates, polyphenols, calcium, oxalates inhibit DMT1 absorption of non-heme iron. Heme is absorbed intact through HCP1, bypassing all these inhibitors.

3

Animal Source Polypeptide Matrix

HIP is derived from animal (typically porcine or bovine) hemoglobin — partially digested to produce a heme-peptide complex. Mimics dietary heme iron from red meat (the most bioavailable dietary iron form).

4

Reduced Mucosal Irritation

No free Fe²⁺ in GI lumen means no oxidative damage to mucosal cells — basis for substantially better tolerability.

Clinical trials

1
Heme Iron Polypeptide vs Ferrous Fumarate

Clinical trial comparing heme iron polypeptide vs ferrous fumarate for absorption when taken with meals.

Adults with iron deficiency.

When taken with meals, HIP iron absorption was significantly higher than ferrous fumarate. Side effects substantially fewer with HIP. Established HIP's value for meal-time iron supplementation.

2
Proferrin Use in Pregnancy — Open-Label

Open-label studies of HIP in pregnant women with IDA who could not tolerate ferrous salts.

Pregnant women with IDA + sulfate intolerance.

HIP raised hemoglobin in pregnancy IDA with minimal side effects. Open-label limitation; not direct comparison to bisglycinate or sulfate at equivalent elemental doses.

Side effects and drug interactions

Common Potential side effects

Generally very well-tolerated.
Mild GI distress at high doses (uncommon).
Dark/normal stools (less staining than ferrous salts).
Cost — significantly more expensive than ferrous salts.
Animal-derived — not appropriate for vegetarians/vegans.

Important Drug interactions

Very few drug interactions vs ferrous salts.
Calcium — does not meaningfully reduce heme iron absorption (advantage).
PPIs/H2 blockers/antacids — do not meaningfully reduce heme iron absorption (advantage).
Coffee/tea tannins — do not meaningfully reduce heme iron absorption.
Tetracyclines/quinolones — not chelated by heme; minimal interaction (advantage).
Levothyroxine — minimal interaction (advantage).
Vitamin C — enhances ferrous salt absorption but minimal effect on heme iron (already well-absorbed).
Main practical advantage: heme iron can be taken with calcium, dairy, PPIs, coffee, with meals — without absorption loss.

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Frequently asked questions about Heme Iron Polypeptide (HIP)

What is heme iron polypeptide?

Heme iron polypeptide is iron in the heme form (derived from animal hemoglobin), the same highly absorbable form found in meat. It is absorbed through a different pathway than non-heme iron salts, with less interference from food and fewer digestive side effects.

Is heme iron better absorbed than regular iron?

Heme iron is absorbed more efficiently and is less affected by inhibitors like coffee, tea, and calcium, so it often works at lower doses with less stomach upset. It is a good option for those who struggle with conventional iron salts, though it is animal-derived.

How much heme iron polypeptide should I take?

Because it is well absorbed, effective amounts of elemental iron are relatively low; follow the product label. Only supplement iron for a confirmed deficiency, ideally under medical guidance.

Does heme iron cause fewer side effects?

Generally yes. Because it is absorbed through a dedicated pathway and less of it remains in the gut, heme iron tends to cause less constipation and nausea than ferrous salts. It is not suitable for vegetarians or vegans, since it comes from animal blood.

What is Heme Iron Polypeptide used for?

Heme Iron Polypeptide is researched primarily for Bone Health and Immune Support. Heme iron uses the HCP1 (heme carrier protein 1) transporter — different from non-heme iron's DMT1 pathway. Means heme iron absorption is not affected by phytates, polyphenols, calcium, or PPI use. Reliable absorption with meals.

What is the recommended dosage of Heme Iron Polypeptide?

The clinically studied dose is 10-22 mg elemental heme iron/day; Proferrin Forte = 11 mg elemental iron per tablet Always follow the product label and check with a healthcare provider for personal advice.

Is Heme Iron Polypeptide safe, and does it have side effects?

For most healthy adults, Heme Iron Polypeptide is well tolerated at studied doses. Reported effects can include: Generally very well-tolerated. Mild GI distress at high doses (uncommon). It may also interact with some medications. Heme Iron Polypeptide is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Heme Iron Polypeptide interact with any medications?

Possible interactions include: Very few drug interactions vs ferrous salts. Calcium — does not meaningfully reduce heme iron absorption (advantage). If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Heme Iron Polypeptide?

NutraSmarts rates the evidence for Heme Iron Polypeptide as Moderate (3 out of 5). It is backed by 2 clinical trials and 1 cited reference summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(1 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Bah M, Verhoef H, Okoh E, et al. Heme iron compared with ferrous iron salts to treat iron deficiency anemia in Gambian children: a randomized controlled trial. Am J Clin Nutr. 2025;122(4):997-1005..PubMedUsed to support: Randomized trial comparing heme iron with ferrous salts for treating iron deficiency anemia.