Erythropoietin dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Erythropoietin, or EPO, is the kidney hormone that tells your body to make red blood cells.
Evidence grade for Erythropoietin: Strong. The rule: at least two finished studies in people, and at least 1,000 people who took it. The sum on this page: 3 completed trials, 4,641 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 4,641
- Human studies
- 3
- Found nothing
- 0
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
FDA approved since 1989 for anaemia (too few red blood cells), with the FDA's strongest (boxed) warnings. Checked on 11 September 2026: EPOGEN and PROCRIT (epoetin alfa, BLA 103234) approved 1 June 1989; ARANESP (darbepoetin alfa, BLA 103951) approved 17 September 2001; MIRCERA (BLA 125164) approved 14 November 2007; RETACRIT (BLA 125545) approved 15 May 2018. All listed Prescription. The boxed warning covers a higher risk of death, heart attack, stroke, blood clots in the veins, clots in the access point used for dialysis, and tumours growing or coming back.
6 effects reported, 3 unwanted, 3 wanted, by people using it, not a trial
Goal pages: Muscle and strength, Brain, memory and mood, Heart and circulation, Sleep
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
EPO is the kidney hormone that tells your body to make red blood cells. Lab-made EPO treats anaemia in kidney disease and during chemo. It is also a famous doping drug in endurance sport. Every product carries the FDA's strongest warning.
What people take it for
- Treating anaemia in kidney disease or during chemo.
- Boosting endurance, which is doping and is banned.
- Protecting the brain and nerves, which has not led to an approved use.
What studies in people showed
Pushing blood counts up to normal caused harm. In 4,038 people with diabetes, kidney disease and anaemia, strokes hit 101 people on the drug against 53 on a dummy shot. In 1,432 people with kidney disease, a higher target meant more deaths, heart attacks, strokes and heart failure. In 603 people, a normal target gave no heart benefit, and more needed dialysis. A review of 50 studies in 4,351 patients found no approved brain use. In healthy adults, it did raise peak power and time to exhaustion.
What people report
Reports, not study results
The good
- Fewer people needed blood transfusions, 297 against 496 in the big study.
- Tiredness got a little better, and general health scores went up in one study.
- In healthy adults, peak power and time to exhaustion went up.
The bad
- Twice as many strokes in the biggest study.
- More deaths, heart attacks and heart failure at the higher blood count target.
- Thick blood and sticky platelets raise clot risk, and doping doses run higher than anything studied.
Where these come from: No user reports. These come from the TREAT, CHOIR and CREATE studies, the reviews and the FDA label on this page.
My bottom line
EPO is a real medicine for real anaemia, with real risks. If your red cell count is low, find out why with blood work. Using it to race faster is a stroke risk with a ban attached.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Erythropoietin has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Kidney function4,641 people · 2 studies
- Heart attacks and strokes4,038 people · 2 studies
- Energy and fatigue4,038 people · 1 study
- Getting stronger603 people · 1 study
- Mood and anxietyno headcount stated · 1 study
- Blood pressureno headcount stated · 1 study
29 of the 36 indexed goals have no study of any kind behind Erythropoietin
No study in people, animals or cells on this page reports a result for these. That does not prove Erythropoietin does nothing for them. It does mean anything you have heard about Erythropoietin and one of these did not come from a study cited here.
Show full evidence
What is Erythropoietin?
Erythropoietin, or EPO, is the kidney hormone that tells your body to make red blood cells. It has been approved since 1989 for anaemia, meaning too few red blood cells. Three big studies tried pushing blood counts up to normal. They found harm, not benefit, including twice as many strokes in 4,038 people. Every product now carries the FDA's strongest warning.
EPO is a hormone made mainly by the kidneys when oxygen runs low. It tells the bone marrow to make more red blood cells. Lab-made versions changed how doctors treat anaemia in kidney disease and during chemo. They also became one of the most famous doping drugs in endurance sport.
The most important part of this story is what happened when studies tried to fix anaemia all the way, not just partly. The biggest was TREAT, run by Amgen. It gave 4,038 people with type 2 diabetes, kidney disease and anaemia either darbepoetin alfa or a dummy shot. Neither main goal improved. Strokes, fatal or not, hit 101 people on the drug against 53 on the dummy shot. That is 1.92 times the risk. A follow-up look could not explain the extra strokes by blood pressure, blood count, platelets or dose.
CHOIR gave 1,432 people with kidney disease a blood count (haemoglobin) target of 13.5 or 11.3 g/dL. The higher target led to more deaths, heart attacks, strokes and hospital stays for heart failure, 1.34 times the risk. Quality of life did not improve. The study is listed as stopped early. Johnson and Johnson ran it. CREATE gave 603 people a normal or a lower target. Aiming for normal gave no heart benefit, and the small gap could be chance. More people in the normal group needed dialysis, 127 against 111. Hoffmann-La Roche ran it.
Those results are why the label now opens with a boxed warning, the FDA's strongest. It says these drugs raise the risk of death, heart attack, stroke, blood clots, clots in dialysis access, and cancer growing or coming back. It says no study has found a blood count target, dose or plan that avoids those risks.
We checked the US drug records on 11 September 2026. EPOGEN and PROCRIT (epoetin alfa, BLA 103234, Amgen) were approved on 1 June 1989. ARANESP (darbepoetin alfa, BLA 103951, Amgen) was approved on 17 September 2001. MIRCERA (methoxy polyethylene glycol-epoetin beta, BLA 125164) was approved on 14 November 2007. RETACRIT (epoetin alfa-epbx, BLA 125545) was approved on 15 May 2018. All are listed as prescription.
How does Erythropoietin work?
In people, EPO docks on its receptor on young blood cells in the bone marrow. That keeps them alive and makes them multiply. Red cell numbers rise over days to weeks. The same signal also thickens the blood and makes platelets stickier. That is the accepted reason for the clots and strokes in the studies that pushed blood counts to normal. EPO receptors have also been found outside the marrow, including in the brain. That is the idea behind using it to protect the brain. That work has not led to any approved use in people.
What have studies in people found about Erythropoietin?
Large studies, and mostly a warning. Three major studies, with more than 6,000 people in total, tried pushing blood counts toward normal. They found no benefit, and the largest found twice as many strokes. A separate set of studies tested EPO to protect the brain and nerves. It has not led to an approved use.
- Brain and nerve protection: a review of 50 human studies in 4,351 patients found a mixed bag. 13 studies reported side effects, and 3 blamed serious problems on EPO. No use has been approved.
- TREAT (4,038 people): neither main goal improved. Stroke hit 5.0 percent against 2.6 percent, 1.92 times the risk. Fewer people needed blood transfusions (297 against 496), and tiredness improved only a little.
- TREAT stroke look-back: the doubled stroke risk could not be explained by patients' starting features, blood pressure, blood count reached, platelets or dose.
- CHOIR (1,432 people): the higher blood count target gave a 34 percent higher rate of death, heart attack, heart failure hospital stays and stroke combined. Quality of life did not improve. The registry lists the study as stopped early.
- CREATE (603 people): fixing anaemia all the way gave no heart benefit, and more people needed dialysis (127 against 111). General health and physical function scores did improve.
- Performance: a review of studies in healthy adults found low to moderate quality evidence that EPO raises blood measures, peak power and time to exhaustion. The gains showed up mostly at all-out effort.
What this does not tell you: The harm studies tested a plan, aiming for a high blood count, not the hormone on its own. So they do not show that EPO is harmful at doses that fix severe anaemia, which is still its approved use. They also took people with kidney disease and diabetes, whose heart risk is already high. The performance studies are small, in healthy volunteers, and measure lab exercise tests. That is not the same as a race. They say nothing about the doses or the clot risk of secret use.
The state of the research
EPO is the clearest example on this site of a lab number that looked like a health outcome. Anaemia predicts death in kidney disease. EPO fixes anaemia. So the thinking was that fixing it fully would cut deaths. Big studies tested that three times, and it failed three times, once with twice as many strokes. The FDA answered with a boxed warning. It says in plain words that no target, dose or plan has been found that avoids the risk. Hold on to that story whenever a compound is pushed because it moves a number the right way.
The doping story runs alongside. EPO changed endurance sport in the 1990s. It is banned in and out of competition under the World Anti-Doping Agency's section S2. Studies in healthy volunteers do show gains in peak power and time to exhaustion. That is unusual, because most doping drugs have thinner evidence than their reputation. The clot risk the kidney studies found in patients comes from the same process that makes secret use in athletes dangerous. And doping doses and blood counts run higher than anything the studies tested.
One peptide on this site comes straight from this hormone. ARA-290 is a piece of EPO built to keep the tissue-protecting signal without raising red cell counts. That design exists precisely because of the studies above.
The evidence, in charts
Fig. 1a · how many people
4,641people, across 2 studies in people cited here
| Study | People | Share |
|---|---|---|
| TREAT, New England Journal of Medicine 2009 | 4,038 | 87% |
| CREATE, New England Journal of Medicine 2006 | 603 | 13% |
One study holds 87% of these people, so the total rests more on one study than its size suggests. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 2 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
4 of 7 sources here are studies in people. The rest are not.
- Study in people · done in people457%
- Review of studies · sums up other studies343%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 6 different years, 2006 to 2023, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Approved
UK
Approved
AU
Approved
CA
Approved
Approved in all four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 5 · what the molecule is
- Kind of compound
- Biologic
- Molecule weight
- Not on file
- Half-life
- About 8.5 hoursMedium, 6 to 24 hours
- Chain length
- None on file
No amino acid sequence is on file for Erythropoietin, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2006Correction of anemia with epoetin alfa in chronic kidney disease
Pushing blood counts up to normal in kidney disease harmed people. 1,432 adults with long-term kidney disease were treated towards either a high or a lower blood count target, for about 16 months. Deaths, heart attacks, heart failure hospital stays and strokes were more common in the high target group, 125 events against 97. Quality of life did not improve. Everybody knew which target they were on. The study was stopped, and the company behind the drug ran it.
CHOIR: 1,432 people with chronic kidney disease randomised open-label to a haemoglobin target of 13.5 or 11.3 g/dL, median 16 months. The composite of death, myocardial infarction, heart failure hospitalisation and stroke occurred 125 times in the high-target group and 97 times in the low-target group, hazard ratio 1.34, 95 percent confidence interval 1.03 to 1.74, p = 0.03, with no improvement in quality of life. Registry status TERMINATED; sponsor Johnson and Johnson Pharmaceutical Research and Development.
- Study in people2006Normalization of hemoglobin level in patients with chronic kidney disease and anemia
Aiming for a normal blood count did not help, and more of those patients ended up on dialysis. 603 people with failing kidneys were treated towards a normal or a lower blood count target and followed for three years. Heart events came out about the same, 58 against 47, a gap that could be chance. More people in the normal target group needed dialysis, 127 against 111. General health and physical function scores did improve. Roche, which sells the drug, ran it.
CREATE: 603 people with estimated GFR 15 to 35 randomised to a normal (13.0 to 15.0 g/dL) or subnormal (10.5 to 11.5 g/dL) haemoglobin target using epoetin beta, 3 years. First cardiovascular events 58 versus 47, hazard ratio 0.78, 95 percent confidence interval 0.53 to 1.14, p = 0.20. More people in the normalisation group needed dialysis, 127 versus 111, p = 0.03. General health and physical function scores improved. Sponsor Hoffmann-La Roche.
- Study in people2009A trial of darbepoetin alfa in type 2 diabetes and chronic kidney disease
This drug did not extend life or save kidneys, and it doubled the risk of stroke. 4,038 people with type 2 diabetes, kidney disease and anaemia got darbepoetin alfa or a dummy shot, with rescue treatment if counts dropped too low. Death and heart events came out the same. Kidney failure came out the same. Strokes hit 101 people on the drug against 53 on the dummy. Fewer needed transfusions, and tiredness improved a little. Amgen, which sells it, paid for the study.
TREAT: 4,038 people with type 2 diabetes, chronic kidney disease and anaemia randomised to darbepoetin alfa targeting 13 g/dL or to placebo with rescue below 9 g/dL. Death or a cardiovascular event, hazard ratio 1.05 (0.94 to 1.17); death or end-stage renal disease, hazard ratio 1.06 (0.95 to 1.19). Fatal or non-fatal stroke 101 versus 53, hazard ratio 1.92, 95 percent confidence interval 1.38 to 2.68, p < 0.001. Fewer transfusions (297 versus 496) and only a modest improvement in fatigue. Sponsor Amgen.
- Study in people2011Stroke in patients with type 2 diabetes mellitus, chronic kidney disease, and anemia treated with Darbepoetin Alfa: the TREAT experience
The stroke harm was real and there is no way to screen for it. Researchers went through all 154 strokes in the earlier trial. Five in every hundred on darbepoetin had a stroke, against about two and a half on the dummy injection. Being assigned the drug predicted stroke on its own. It could not be explained away by who the patients were at the start, nor by their blood pressure, blood counts, platelets or dose afterwards. So monitoring those things does not make the drug safer.
Analysis of the 154 strokes in TREAT: 5.0 percent of the darbepoetin group and 2.6 percent of the placebo group. Assignment to darbepoetin was an independent predictor (odds ratio 2.1, 95 percent confidence interval 1.5 to 2.9). The doubling could not be attributed to baseline characteristics or to post-randomisation blood pressure, haemoglobin, platelet count or dose, so the risk could not be mitigated by monitoring those.
- Review of studies2021Systematic Review of Erythropoietin (EPO) for Neuroprotection in Human Studies
A review of 50 human studies covering 4,351 patients, picked from 388 papers. 13 studies reported side effects. 3 blamed serious problems on EPO, 2 of them when it was given with the clot-busting drug tPA. Most work is in spinal cord injury, surgery and the brain. No approved use for protecting the brain has come of it.
50 studies covering 4,351 patients, screened from 388 citations. 13 studies reported adverse effects and 3 attributed serious adverse events to EPO, 2 of those in combination with tissue plasminogen activator. Most work is in spinal cord injury, perioperative outcomes and central nervous system effects. No approved neuroprotection indication has resulted.
- Review of studies2020Effect of erythropoietin on athletic performance: a systematic review and meta-analysis
A review of studies giving EPO or a dummy to healthy adults aged 18 to 65. Low to moderate quality evidence says EPO raises blood measures, peak power and time to exhaustion, whatever the dose. The gains showed up almost only at all-out effort, which may not match a real race.
Systematic review of randomised trials of recombinant human EPO versus placebo in healthy adults aged 18 to 65. Low to moderate quality evidence that EPO improves haematological measures, maximal power output and time to exhaustion regardless of dose, with the improvements seen almost exclusively at maximal exercise intensities that may not reflect competition conditions.
- Review of studies2023Doping and sports endocrinology: growth hormone, IGF-1, insulin, and erythropoietin
A review of EPO and similar drugs banned by the World Anti-Doping Agency, in and out of competition. It covers how common use is, how people dose, what it does for performance, side effects, and how testers catch it.
Review of erythropoietin and other erythropoiesis-affecting agents among the substances prohibited by the World Anti-Doping Agency in section S2, peptide hormones, growth factors, related substances and mimetics, which is prohibited both in and out of competition. Covers prevalence, dosing, ergogenic effects, side effects and detection.
Common questions
Has Erythropoietin been tested in people?
Yes. 4,641 people given it across 3 completed trials cited here, 0 of which found nothing. Erythropoietin, or EPO, is the kidney hormone that tells your body to make red blood cells.
What is the Erythropoietin dosage?
Approved medicine. No human dose established for unlabelled uses. Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose. FDA approved since 1989 for anaemia (too few red blood cells), with the FDA's strongest (boxed) warnings. Checked on 11 September 2026: EPOGEN and PROCRIT (epoetin alfa, BLA 103234) approved 1 June 1989; ARANESP (darbepoetin alfa, BLA 103951) approved 17 September 2001; MIRCERA (BLA 125164) approved 14 November 2007; RETACRIT (BLA 125545) approved 15 May 2018. All listed Prescription. The boxed warning covers a higher risk of death, heart attack, stroke, blood clots in the veins, clots in the access point used for dialysis, and tumours growing or coming back.
Is Erythropoietin FDA-approved?
FDA approved since 1989 for anaemia (too few red blood cells), with the FDA's strongest (boxed) warnings. Checked on 11 September 2026: EPOGEN and PROCRIT (epoetin alfa, BLA 103234) approved 1 June 1989; ARANESP (darbepoetin alfa, BLA 103951) approved 17 September 2001; MIRCERA (BLA 125164) approved 14 November 2007; RETACRIT (BLA 125545) approved 15 May 2018. All listed Prescription. The boxed warning covers a higher risk of death, heart attack, stroke, blood clots in the veins, clots in the access point used for dialysis, and tumours growing or coming back.
Why does erythropoietin carry a boxed warning?
Because big studies that aimed for higher blood counts found more harm, not less. CHOIR found a 34 percent higher rate of death, heart attack, heart failure hospital stays and stroke at the higher target. TREAT found stroke in 5.0 percent, against 2.6 percent on a dummy shot. The label says no blood count target, dose or plan has been found that avoids these risks.
Does EPO improve athletic performance?
A review of studies in healthy adults found low to moderate quality evidence that it raises blood measures, peak power and time to exhaustion. The gains showed up almost only at all-out effort. The authors note that may not match a real race. EPO is banned in and out of competition.
Is EPO used for brain protection?
It has been studied for that, and no approved use has come of it. A review of 50 human studies in 4,351 patients found a mixed bag, mostly in spinal cord injury and around surgery. 13 studies reported side effects. 3 blamed serious problems on EPO, 2 of them when it was given with the clot-busting drug tPA.
What is the difference between epoetin alfa and darbepoetin alfa?
Both work on the same receptor. Darbepoetin carries more sugar chains, so it lasts longer. The epoetin alfa label says half of it is gone in 4 to 13 hours after a drip in kidney disease. For darbepoetin, it is about 21 hours on average. Both carry the same boxed warning.