Erythropoietin (EPO)

also known as: EPO, Epoetin alfa, Epoetin beta, Darbepoetin alfa, Epogen, Procrit, Aranesp, rHuEPO, rhEpo

A glycoprotein hormone that drives red blood cell production; recombinant forms are FDA-approved standards of care for anemia of chronic kidney disease and chemotherapy-induced anemia, and have a notorious history of misuse in endurance sport.

An erythropoiesis-stimulating agent (ESA) that binds EPO receptors on CD34+ hematopoietic progenitors to drive red blood cell maturation, widely used in renal and oncology medicine, and a central figure in the sport-doping history of the late 20th and early 21st centuries.

Mechanism of action

Binds the EPO receptor (EPOR, a member of the type I cytokine receptor family) on the surface of CD34+ hematopoietic progenitor cells in bone marrow. Receptor dimerization activates JAK2/STAT5 signaling, promoting erythroid progenitor proliferation, differentiation, and survival (anti-apoptosis). Endogenous EPO is upregulated by hypoxia via HIF-2α-mediated transcription in renal peritubular cells. Tissue-protective effects (anti-apoptosis, anti-inflammation) have also been observed in heart, brain, and kidney in preclinical studies, though these remain investigational clinically.

Primary uses

Anemia of chronic kidney disease
Chemotherapy-induced anemia (non-myeloid malignancies)
Anemia associated with zidovudine in HIV
Reduction of perioperative transfusion in elective surgery
Illicit performance-enhancement in endurance sport (WADA-banned)

Typical dosing

50–300 IU/kg 2–3x weekly (epoetin); every 2–4 weeks (darbepoetin) (intravenous or subcutaneous)

Dose titrated to hemoglobin target (typically 10–11 g/dL in CKD; higher targets increase cardiovascular risk). Darbepoetin is dosed in mcg/kg, not IU/kg.

Regulatory status

FDA-approved indications: anemia of chronic kidney disease (CKD), chemotherapy-induced anemia in non-myeloid cancers, zidovudine-treated HIV anemia, and reduction of allogeneic red blood cell transfusions in elective non-cardiac non-vascular surgery. Black-box warnings for increased cardiovascular events, thrombosis, and mortality/tumor progression in cancer patients when hemoglobin targets exceed recommended levels.

References

[review] Jelkmann W. "Physiology and pharmacology of erythropoietin." Transfus Med Hemother, 2013;40(5):302-309.
[fda-label] FDA Prescribing Information: EPOGEN (epoetin alfa) — Amgen, revised 2017.
[review] Fishbane S, Spinowitz B. "Update on anemia in ESRD and earlier stages of CKD: core curriculum 2018." Am J Kidney Dis, 2018;71(3):423-435.

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Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.