Rusfertide
Also known as: Mimrylo, PTG-300, TAK-121
A hepcidin-mimetic peptide that limits iron supply for red cell production. FDA-approved as Mimrylo (2026) for polycythemia vera. Prescription medication.
Last updated
Mechanism of Action
Rusfertide is a synthetic peptide that mimics hepcidin, the liver hormone that controls iron availability. It binds and degrades ferroportin, the iron exporter on gut cells and macrophages, which reduces iron delivery to the bone marrow. In polycythemia vera, restricting iron in this way slows excess red blood cell production and helps keep hematocrit controlled with fewer phlebotomies.
- Half-life
- Not well established
- Administration Routes
- Subcutaneous
- Research Status
- Clinical
Reported Benefits
- Controls hematocrit in adults with polycythemia vera
- Reduced the need for therapeutic phlebotomy (REVIVE, VERIFY)
- Improves iron-deficiency markers caused by repeated phlebotomy
Potential Side Effects
- Injection-site reactions (most common)
- Anemia
- Fatigue
- New or worsening thrombocytosis (label warning)
Common Dosing
Mimrylo is given as a once-weekly subcutaneous injection, with the dose adjusted over time to keep hematocrit in the target range, and blood counts are checked regularly. Dosing is set and supervised by the prescribing clinician.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- No contraindications listed on the US label
- Embryo-fetal toxicity: contraception advised (label warning)
- Monitor for thrombocytosis with regular blood counts
No documented stacking partners for Rusfertide yet.