# EPO (Erythropoietin) > A glycoprotein hormone that drives red-blood-cell production — a recombinant biologic famous in medicine for treating anemia and infamous in sport for blood doping. - Also known as: Erythropoietin, Epoetin alfa, Epogen, Procrit, recombinant human erythropoietin, rhEPO - Class: Healing & Repair - FDA approved: Yes - Canonical page: https://www.americanpeptide.com/catalog/epo ## Overview Erythropoietin is the hormone the kidneys release to tell the bone marrow to make more red blood cells. It is a 165-amino-acid glycoprotein, roughly 30–34 kDa once its sugar chains are counted, and like other glycoprotein hormones its carbohydrate is not optional — the glycosylation governs its stability and circulating half-life. Recombinant versions (epoetin alfa and its relatives) are produced in mammalian cells so that human-like glycosylation occurs, and beyond its core role in red-cell production it has a substantial research literature in tissue protection. EPO is a glycoprotein, and that places it firmly in the biologic tier of this catalog. Its 165-residue chain folds into a four-helix bundle (the same architectural family as growth hormone) and is decorated with three N-linked and one O-linked glycan. Those sugars are functionally decisive: more heavily glycosylated, engineered versions (such as darbepoetin) circulate far longer. This is why EPO is made in mammalian cell culture rather than bacteria — only a eukaryotic cell adds the human-style glycosylation the molecule needs. In medicine it is well established and genuinely important: recombinant EPO treats the anemia of chronic kidney disease, chemotherapy, and other marrow-suppressed states, sparing transfusions for millions. Its receptor turns up in the nervous system and elsewhere, which has driven a long research thread into EPO as a cytoprotective and neuroprotective agent after ischemic injury — promising in models, unproven as therapy. Then there is the doping. EPO became the defining drug of endurance-sport scandals: by raising red-cell mass it boosts oxygen delivery and stamina, and it sat at the center of professional cycling’s doping era. The misuse carries real danger — thickened blood raises the risk of clots, stroke, and heart attack — and the same caution emerged in medicine, where trials showed that over-correcting hemoglobin to normal or high targets increased cardiovascular events and mortality. EPO is a clean example of a molecule whose reputation splits sharply between its legitimate, life-improving medical use and its dangerous performance misuse. ## Mechanism Binds the erythropoietin receptor on red-cell progenitors in the bone marrow, activating JAK2/STAT5 signaling that promotes their survival, proliferation, and maturation into erythrocytes — raising the blood’s oxygen-carrying capacity. The same receptor is expressed in other tissues, the basis for its cytoprotective research. ## Chemistry | Property | Value | | --- | --- | | Molecular weight | 30400 Da | | CAS number | 113427-24-0 | | UniProt | [P01588](https://www.uniprot.org/uniprotkb/P01588) | ## Research areas Studied in: Anemia, Tissue protection, Neuroprotection, Erythropoiesis. Guides on this site: - [Cognition & Neuroprotection](https://www.americanpeptide.com/research-areas/cognition-neuroprotection): Nootropic and neurotrophic peptides studied for cognition and recovery. ## Key research - Anemia of chronic kidney disease — the core approved use, replacing the EPO failing kidneys no longer make. - Chemotherapy-induced anemia — used to reduce transfusion need in selected patients. - Hemoglobin-target caution — trials found that normalizing/over-correcting hemoglobin raised cardiovascular events and mortality, reshaping dosing. - Tissue/neuroprotection — EPO-receptor signaling outside marrow is studied for cytoprotection after ischemic injury (research, not approved). - Endurance doping — banned in sport; raising red-cell mass increases clot, stroke, and heart-attack risk. - Glycosylation engineering — added glycans (darbepoetin) extend half-life, underscoring that the sugar defines the drug. ## Storage, handling & synthesis **Storage.** Recombinant EPO is stored refrigerated (2–8 °C) and protected from light; it must not be frozen or shaken. Glycoprotein integrity is sensitive to heat and freeze–thaw. **Handling.** A glycosylated protein sensitive to heat, freezing, and agitation, which can aggregate it and reduce potency. Aggregated protein is also an immunogenicity concern — historically linked to rare pure red-cell aplasia from anti-EPO antibodies. **Synthesis.** EPO is produced recombinantly in mammalian (CHO) cell culture so that its essential N- and O-linked glycosylation is human-like; its ~30–34 kDa mass is approximate and varies with glycosylation, so it has no single molecular formula. Characterization is glycoprotein-grade — glycan/isoform profiling, identity by mass spectrometry and peptide mapping, and cell-based potency — far beyond an HPLC purity figure. ## FAQs ### What is EPO? Erythropoietin — a glycoprotein hormone, mainly from the kidneys, that signals the bone marrow to produce red blood cells. Recombinant EPO (epoetin alfa) treats anemia in kidney disease and chemotherapy. ### Why is EPO a biologic rather than a peptide? It is a folded, glycosylated 165-amino-acid protein whose sugar chains are essential to its activity and half-life. It is produced in mammalian cells so that human-like glycosylation occurs — something bacterial peptide synthesis cannot do. ### Why is EPO associated with doping? By increasing red-cell mass it raises oxygen delivery and endurance, which made it a notorious performance drug, especially in cycling. The misuse is dangerous — it thickens the blood and raises clot, stroke, and heart-attack risk. ### Is this medical advice? No — this is a research and educational reference. EPO is a prescription biologic with significant cardiovascular risks when misused. ## Latest research Recent trials and publications mentioning Erythropoietin, pulled automatically from ClinicalTrials.gov and PubMed (unfiltered search results, refreshed daily). ### Recent trials - [Effects of Intravenous Injection of Erythropoietin on Hepcidin Pharmacokinetics in Healthy Volunteers](https://clinicaltrials.gov/study/NCT00687518) — COMPLETED · NA · NCT00687518 - [MYELOMATCH: A Screening Study to Assign People With Myeloid Cancer to a Treatment Study or Standard of Care Treatment Within myeloMATCH (MyeloMATCH Screening Trial)](https://clinicaltrials.gov/study/NCT05564390) — RECRUITING · PHASE2 · NCT05564390 - [Safety of Erythropoietin and Melatonin for Very Preterm Infants With Intraventricular Hemorrhage](https://clinicaltrials.gov/study/NCT05617833) — RECRUITING · PHASE1 · NCT05617833 - [Luspatercept vs Epoetin in Treating Poor Erythroid Engraftment for Hematological Malignancies](https://clinicaltrials.gov/study/NCT07636486) — NOT_YET_RECRUITING · PHASE2, PHASE3 · NCT07636486 - [Combined Dose-Finding and CV Outcomes Study With CSL300 (Clazakizumab) in Adult Subjects With ESKD Undergoing Dialysis (POSIBIL6ESKD)](https://clinicaltrials.gov/study/NCT05485961) — RECRUITING · PHASE2, PHASE3 · NCT05485961 - [Study of Two Doses of Crizanlizumab Versus Placebo in Adolescent and Adult Sickle Cell Disease Patients](https://clinicaltrials.gov/study/NCT03814746) — ACTIVE_NOT_RECRUITING · PHASE3 · NCT03814746 --- Source: AmericanPeptide.com — https://www.americanpeptide.com/catalog/epo Data license: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Attribution: AmericanPeptide.com. Research reference only — computational and educational content, not medical advice.