Pegmolesatide
A synthetic peptide that switches on the erythropoietin receptor, injected once every four weeks for kidney-disease anaemia in China
Pegmolesatide is not erythropoietin and shares none of its sequence, but it binds and activates the same receptor, so it drives red blood cell production the same way. A polyethylene glycol chain makes it last long enough for one injection every four weeks. China's drug regulator approved it in June 2023 for anaemia of chronic kidney disease after two phase 3 trials found it held haemoglobin at least as well as epoetin alfa given one to three times a week. It is not approved in the US or Europe, and it is on the anti-doping list.
Used in human trials: 0.04 mg/kg to start (maximum 0.08 mg/kg), Once every 4 weeks, adjusted every 4 weeks to haemoglobin 100-120 g/L, Subcutaneous (upper arm) (Phase 3 (2025): CKD anaemia, not on dialysis) Details ↓
Recommended Dosing
Used in human trials
There is no FDA label. A label from outside the US exists (see the regulatory status on this page) but was not read for this page: these are amounts given in published trials, not recommendations.
Work out syringe units → · New to syringes? · All dosing data ↓
What is it?
People with chronic kidney disease often become anaemic because their kidneys make too little erythropoietin (EPO), the hormone that tells bone marrow to make red blood cells. The standard treatment is recombinant EPO, such as epoetin alfa, injected one to three times a week, or longer-acting versions. Pegmolesatide takes another route: it is a synthetic peptide built to fit the EPO receptor and switch it on, with a polyethylene glycol (PEG) chain attached so it stays in the body for weeks.
Its developer, Hansoh in China, reported in 2025 that in cells it stayed bound to the EPO receptor longer than recombinant EPO or darbepoetin and kept the receptor's growth signals running after the drug was washed out. In mice a single dose kept red cell counts raised for four to six days, and two Chinese phase 2 trials found haemoglobin rose with dose and the response lasted. A separate 2024 laboratory study concluded it stimulated red cell production as EPO did.
The approval rests on two open-label phase 3 trials, both against epoetin alfa and both in China. In 372 people on dialysis, already treated with epoetin, switching to pegmolesatide every four weeks kept haemoglobin as well as staying on epoetin: the mean change was +0.07 g/dL against −0.22 g/dL. In 173 people not on dialysis, haemoglobin rose by 19.2 g/L on pegmolesatide and 15.4 g/L on epoetin. A pooled re-analysis of the two trials found haemoglobin varied a little less from month to month on pegmolesatide, and fewer major cardiovascular events, though the numbers were small and the differences not significant.
China's National Medical Products Administration announced the approval on June 30, 2023, for adults with kidney-disease anaemia who are not on dialysis and have not had an EPO drug, and for people on dialysis being treated with short-acting EPO. Since then a real-world cohort of 192 dialysis patients switched to it saw haemoglobin climb by about 13 g/L in three months and hold for a year, and a case report describes it working in a man who developed pure red cell aplasia, a rare complication of EPO treatment in which the marrow stops making red cells.
There is a reason the trials reported allergic reactions so carefully. Peginesatide, an earlier PEGylated EPO-mimetic peptide, was approved in the US in 2012 and recalled the next year after severe, sometimes fatal, reactions to the first dose (see its entry). The pegmolesatide trials reported no fatal anaphylaxis and no drug-related hypersensitivity reactions; high blood pressure was the commonest side effect linked to the drug, as it is with EPO itself. Those trials total a few hundred patients for about a year.
For someone who has seen it sold online: anything that raises red cell production thickens the blood, and the risks of EPO drugs, high blood pressure, clots and stroke, rise when haemoglobin is pushed above the range doctors aim for. That is why it is dosed by weight and adjusted every four weeks against blood tests. It is prohibited in sport, and anti-doping laboratories in Beijing have published two tests for it.
Mechanism of Action
Pegmolesatide is an agonist of the erythropoietin receptor: it does EPO's job at the receptor without being EPO.
Activates the EPO receptor
It binds the EPO receptor homodimer, the receptor on red cell precursors, with more stable binding than EPO (PMIDs 39894850, 42553958).
Red cell production
Receptor signalling through JAK2/STAT5 and ERK keeps precursors growing and surviving, raising haemoglobin (PMIDs 39894850, 40225393).
PEG for a long action
The polyethylene glycol chain extends its life in the body, allowing an injection every four weeks (PMIDs 37954906, 39894850).
Heart effects in animals
In rat models it reduced heart muscle enlargement through lower JAK2/STAT3 signalling; this has not been tested in people (PMIDs 42212269, 41092772).
Published Research
These are the studies of pegmolesatide read from their PubMed abstracts on October 29, 2026: two phase 3 trials and their pooled analysis, a real-world cohort and a case report, the developer's preclinical and phase 2 overview, laboratory and rat studies, two anti-doping tests, a manufacturing quality-control method and a Chinese drug assessment. Two of these name it only in the abstract; they are carded because the abstract names pegmolesatide as a drug studied.
Phase 3 in dialysis patients
At 43 Chinese dialysis centres, 372 patients aged 18 to 70 were randomised 2:1 to pegmolesatide every four weeks or epoetin alfa one to three times a week, doses adjusted to keep haemoglobin at 10 to 12 g/dL. The mean change was +0.07 against −0.22 g/dL, meeting the non-inferiority margin. Adverse events occurred in 94% and 89%; hypertension was the commonest drug-related event, and there was no fatal anaphylaxis or hypotension.
Phase 3 in kidney disease without dialysis
At 38 Chinese centres, 173 patients received pegmolesatide in the upper arm every four weeks or epoetin alfa weekly or every two weeks, aiming for haemoglobin of 100 to 120 g/L. Haemoglobin rose 19.2 g/L against 15.4 g/L, a difference of 3.8 g/L. Adverse events were similar; hypertension was the commonest drug-related one, with no drug-related hypersensitivity or deaths.
Both phase 3 trials re-analysed
Pooling 545 patients from the two trials, slightly more on pegmolesatide kept a mean haemoglobin of at least 10 g/dL (not significant), month-to-month haemoglobin varied less in dialysis patients, and major cardiovascular events were numerically fewer (five-point major adverse cardiovascular events 3.7% against 6.5% on dialysis). A post hoc analysis, so it suggests rather than proves.
Switching in routine dialysis care
In a single-centre retrospective study of 192 haemodialysis and peritoneal dialysis patients switched from EPO drugs or a HIF-PH inhibitor, haemoglobin rose from 96.4 to 110.0 g/L by month 3 and held to month 12, and the share at target rose from 19.8% to 54.5%. Thrombotic events (2.6%) all involved the dialysis access; mortality was 2.1%.
Red cell aplasia after EPO: a case
A 35-year-old man with diabetic kidney disease developed pure red cell aplasia, a rare complication of EPO therapy, and needed weekly transfusions despite two HIF-PH inhibitors. On pegmolesatide his haemoglobin started rising within a week and went from 50 to 92 g/L over about three months. One patient, not a trial.
Developer's preclinical and phase 2 overview
In cells it bound the EPO receptor more stably than recombinant EPO and darbepoetin and kept JAK2/STAT5 and ERK signalling active; in mice one dose kept red cell measures raised for 4 to 6 days. Two Chinese phase 2 trials in dialysis and non-dialysis patients found dose-dependent haemoglobin rises and long responses, with mild adverse events and no severe anaphylaxis.
Modelling and cell tests against EPO
Computer modelling and cell experiments compared pegmolesatide with recombinant EPO and carbamylated EPO. The authors concluded it stimulated red cell production as EPO did with fewer side effects than either comparator in their tests.
The heart in rats with kidney failure
In rats with five-sixths of their kidney removed, pegmolesatide improved heart function and reduced heart muscle fibrosis and enlargement, which the authors tie to lower JAK2/STAT3 signalling and better mitochondrial function; human heart cells exposed to serum from kidney patients responded similarly.
Heart cells exposed to a uraemic toxin
In rat heart cells treated with indoxyl sulfate, a toxin that builds up in kidney failure, pegmolesatide reduced markers of cell enlargement and blocked pairing of the EPO receptor with CD131. Adding the CD131 activator ARA-290 cancelled the effect.
First anti-doping test
A Beijing anti-doping laboratory captured pegmolesatide on beads coated with the EPO receptor, digested it and detected two characteristic fragments by mass spectrometry, then validated the method for doping control. The paper describes it as developed by Hansoh.
A faster screening test
An ELISA that captures the drug with the EPO receptor and detects its PEG chain found it at 1 ng/mL in urine and 2 ng/mL in serum, below the mass-spectrometry method's identification limit. The paper notes that WADA lists it as an erythropoietin receptor agonist (S2.1.1).
Measuring free PEG in the product
Free polyethylene glycol is a manufacturing impurity in PEGylated peptides. A validated chromatography method with charged aerosol detection measured it in batches of three such drugs, pegmolesatide among them, including stability samples.
A Chinese drug assessment of long-acting ESAs
A health technology assessment scored three long-acting EPO drugs on efficacy, safety, pharmaceutical properties, cost and other attributes. Pegmolesatide scored 73.04, between the continuous erythropoietin receptor activator, a PEGylated epoetin (80.39) and darbepoetin alfa (71.70), and ranked first on pharmaceutical properties; all three met the threshold for a strong recommendation.
Dosing Data
Pegmolesatide is approved in China, but its label was not read for this page. The row below is from the published phase 3 trial in people not on dialysis, read in its full text: a starting dose by body weight, then adjustment every four weeks against haemoglobin. In the dialysis trial each patient's starting dose was converted from their previous epoetin dose, so no single amount applies.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
Unknown: we hold no label and no published test that says what forms or vial sizes Pegmolesatide is sold in. A vial's own label is a seller's claim, not a source.
Mixing a vial: a worked example
No worked example: none of the doses on this page is a fixed amount in mg or mcg injected under the skin or into a muscle (the routes given are: subcutaneous (upper arm)). There is no home-mixing step to show. The reconstitution calculator does the arithmetic for any vial.
Source: the route and amount of each dose row in Dosing Data below.
Storage before and after mixing
Unknown: no label or published stability study on file says how to store Pegmolesatide, before or after mixing. The mixing guide sets out the general rules, with their sources: keep a mixed vial in the fridge, and use it promptly, as the bacteriostatic water label says of any drug dissolved in it. The 28 days often quoted is the limit for an opened multiple-dose vial from a manufacturer, an outer limit set for sterility, not a time a mixed solution has been shown to keep. Nobody has published how long Pegmolesatide stays intact once mixed.
How it is taken
As it was given in human studies: Subcutaneous (upper arm) (Once every 4 weeks, adjusted every 4 weeks to haemoglobin 100-120 g/L; Phase 3 (2025): CKD anaemia, not on dialysis).
For injection technique, sites and needle disposal, see the mixing guide.
Source: Used in human trials: the route and frequency of each row in Dosing Data below.
What to expect, and when
How long it stays in the body: not established by a measurement cited on this entry.
How long the doses were given: Phase 3 (2025): CKD anaemia, not on dialysis: To week 48.
When effects appear: unknown; no source on this page gives a time to effect for Pegmolesatide. Results reported in the studies are under Published Research.
Source: Used in human trials, the duration of each row in Dosing Data below.
Side effects, and when to stop or get help
From the Side Effects section: Hypertension was the commonest drug-related adverse event in both phase 3 trials (PMIDs 37954906, 40225393); Adverse events of any kind in 94% on pegmolesatide and 89% on epoetin alfa in the dialysis trial, a sick population (PMID 37954906); No fatal anaphylaxis or hypotension, and no drug-related hypersensitivity reactions, in the phase 3 trials (PMIDs 37954906, 40225393); Clots in the dialysis access in 2.6% of a real-world cohort over a year (PMID 42836158). Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping Pegmolesatide. Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“From the trials, the cohort and the case report read”).
Interactions
Unknown: a PubMed search for human interaction studies of Pegmolesatide (reviewed 2026-10-28) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of Pegmolesatide products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: Not FDA Approved. Elsewhere: approved in China (NMPA, 2023). Sport: Prohibited at all times (S2.1.1).
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
From the trials, the cohort and the case report read.
Contraindications & Cautions
The Chinese label was not read for this page. These cautions come from the trials and the drug class.
Legal Status
Approved in China for anaemia of chronic kidney disease; not approved in the US or the EU.
Frequently Asked Questions
?What is pegmolesatide?
A synthetic PEGylated peptide that activates the erythropoietin receptor, approved in China in 2023 to treat anaemia caused by chronic kidney disease. It is injected under the skin once every four weeks.
?Is it a form of EPO?
No. It is a different molecule that works on EPO's receptor. In one reported case it raised haemoglobin in a man who had developed red cell aplasia on EPO therapy.
?How well does it work?
In two phase 3 trials in China it kept or raised haemoglobin at least as well as epoetin alfa given one to three times a week. Both trials were open-label and lasted about a year.
?Is it approved in the US?
No. It is approved only in China; Drugs@FDA and the EMA list hold no record.
?Is it like peginesatide?
Both are PEGylated peptides that activate the EPO receptor. Peginesatide was recalled in the US in 2013 after severe allergic reactions; the pegmolesatide trials reported none that were fatal or drug-related.
?Is it banned in sport?
Yes. WADA lists it as an erythropoietin receptor agonist, and anti-doping laboratories have published tests that detect it in urine and serum.
References
- [clinical-trial] Zhang P, et al. "Pegmolesatide for the treatment of anemia in patients undergoing dialysis: a randomized clinical trial." EClinicalMedicine, 2023;65:102273. PMID: 37954906.
- [clinical-trial] Xie J, et al. "Randomized Trial of Pegmolesatide for the Treatment of Anemia in Patients With Nondialysis CKD." Kidney Int Rep, 2025;10(3):720-729. PMID: 40225393.
- [pubmed] Ye Z, et al. "Efficacy and Cardiovascular Safety of Pegmolesatide in Patients with Anemia of Chronic Kidney Disease: Post hoc Analysis of Two Phase 3 Randomized Trials." Kidney Dis (Basel), 2026;12(1):711-721. PMID: 42553958.
- [pubmed] Luo C, et al. "Switching to Pegmolesatide in Maintenance Dialysis: Real-World Hemoglobin Response, Temporal Dynamics, and Modality-Specific Predictors." Drug Des Devel Ther, 2026;20:632477. PMID: 42836158.
- [pubmed] Chen Q, et al. "EPO-Mimetic Peptide Pegmolesatide Therapy for Pure Red Cell Aplasia in a Patient with Non-dialysis-dependent Type 1 Diabetic Nephropathy: A Case Report." Kidney Med, 2025;7(2):100947. PMID: 39882157.
- [pubmed] Ma X, et al. "Overview of preclinical and phase II clinical studies on Pegmolesatide's long-term erythropoiesis stimulating effect via EPOR-mediated signal transduction." J Transl Med, 2025;23(1):144. PMID: 39894850.
- [pubmed] Zhou EJ, et al. "Modeling and biological evaluation of pegmolesatide, a novel and potent erythropoiesis-stimulating agent." J Asian Nat Prod Res, 2024;26(11):1339-1347. PMID: 38860546.
- [pubmed] Zhang X, et al. "Amelioration of CKD-induced cardiomyocyte hypertrophy by pegmolesatide: involvement of JAK2/STAT3 inhibition and mitochondrial protection." Front Pharmacol, 2026;17:1806374. PMID: 42212269.
- [pubmed] Zhang X, et al. "Pegmolesatide ameliorates indoxyl sulfate-induced cardiomyocyte hypertrophy through modulating the EPOR-CD131-dependent JAK2/STAT3 signaling pathway." Int Immunopharmacol, 2025;167:115643. PMID: 41092772.
- [pubmed] Liu L, et al. "Method Development of Pegmolesatide for Doping Analysis: A Novel Synthetic Erythropoietin-Mimetic Agent." Drug Test Anal, 2025;17(11):2210-2219. PMID: 40675650.
- [pubmed] Chen J, et al. "Development of an Enzyme-Linked Immunosorbent Assay for Pegmolesatide in Doping Analysis: An Initial Testing Method." Drug Test Anal, 2026;18(9):1177-1185. PMID: 42321008.
- [pubmed] Sun Y, et al. "Quantitative analysis of free polyethylene glycols in PEGylated peptides using reverse-phase high-performance liquid chromatography and charged aerosol detection." PLoS One, 2026;21(9):e0357292. PMID: 42691081.
- [pubmed] Wang X, et al. "Health technology assessment of long-acting erythropoiesis-stimulating agents for the treatment of renal anemia in China." Front Pharmacol, 2026;17:1878826. PMID: 42890961.
- [other] US FDA, Drugs@FDA (openFDA): no application for pegmolesatide. Read October 28, 2026.
- [other] National Medical Products Administration (China), news release updated June 30, 2023: Category 1 innovative drug Pegmolesatide Injection approved; applicant Jiangsu Hansoh Pharmaceutical Group. Read October 29, 2026. https://english.nmpa.gov.cn/2023-06/30/c_940313.htm
- [other] National Medical Products Administration (China), news release updated June 30, 2023: Category 1 innovative drug Pegmolesatide Injection approved; applicant Jiangsu Hansoh Pharmaceutical Group. Read October 29, 2026. https://english.nmpa.gov.cn/2023-06/30/c_940313.htm
- [other] National Medical Products Administration (China), news release updated June 30, 2023: Category 1 innovative drug Pegmolesatide Injection approved; applicant Jiangsu Hansoh Pharmaceutical Group. Read October 29, 2026. https://english.nmpa.gov.cn/2023-06/30/c_940313.htm
- [other] National Medical Products Administration (China), news release updated June 30, 2023: Category 1 innovative drug Pegmolesatide Injection approved; applicant Jiangsu Hansoh Pharmaceutical Group. Read October 29, 2026. https://english.nmpa.gov.cn/2023-06/30/c_940313.htm
Sources & Citations
Every study on this page was read from its PubMed record on October 29, 2026; the dose row comes from the full text of the non-dialysis phase 3 trial in PubMed Central. The approval comes from the NMPA's own news release. Grey Peptides sells nothing and links to no vendor.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.