Alexamorelin
A seven-amino-acid growth hormone-releasing peptide tested once in six people, never developed, and now known mainly to doping laboratories
Alexamorelin is a synthetic heptapeptide of the growth hormone-releasing peptide (GHRP) family, the group that includes GHRP-6, GHRP-2 and hexarelin. Its only human study, in 2000, gave single doses to six young adults: growth hormone rose as much as with hexarelin, but so did the stress hormones ACTH and cortisol, more than with hexarelin at the higher dose. It was never taken further as a medicine. Since then nearly every paper about it has come from anti-doping laboratories building tests to catch it.
Used in human trials: 1.0–2.0 mcg/kg, single dose (endocrine testing), intravenous (Studied dose) Details ↓
Recommended Dosing
Used in human trials
No manufacturer dose exists for this use: these are amounts given in published trials, not recommendations.
What is it?
The growth hormone-releasing peptides are small synthetic peptides, four to seven amino acids long, that make the pituitary release growth hormone by acting on the receptor later found to bind ghrelin. Alexamorelin is the seven-residue member: its sequence is hexarelin's with one extra alanine at the front. That relationship is visible in the body too. When a 2025 study incubated alexamorelin with human liver cells, the only metabolite found after three hours was hexarelin itself, formed by cutting off that first alanine, and the alexamorelin signal fell about 150-fold.
Its one human study was published in 2000 by a group that had used hexarelin as its reference growth hormone secretagogue. Six young adults received alexamorelin or hexarelin intravenously at 1 and 2 micrograms per kilogram on separate days, and a single 20 mg oral dose of each. Both peptides raised growth hormone and prolactin to the same degree, rising with dose. Both also raised ACTH and cortisol, but at the higher dose alexamorelin raised them significantly more, and only alexamorelin raised aldosterone. By mouth, growth hormone rose somewhat more than with hexarelin, not significantly. The authors concluded it had the same growth hormone action as hexarelin with a stronger effect on the stress-hormone axis.
No later study gave it to people for any purpose, no trial is registered, and no regulator has approved it. Its literature since 2011 is about detection. The World Anti-Doping Agency names it among the prohibited growth hormone-releasing peptides, and laboratories have published methods to find it intact in urine, to map what rats excrete after a dose, to screen for it alongside other small doping peptides, and to measure it in dried blood spots. One finding there is practical: in liquid serum or plasma kept at fridge or room temperature it was extensively degraded within a week, while in dried blood it stayed detectable.
For someone who has seen it offered online, the evidence comes down to this. There is a single endocrine test in six people, which measured hormone responses over a few hours after one dose and nothing about body composition, recovery or safety over time. What it does show is that the stress-hormone rise was larger than hexarelin's, which matters for anyone who assumes these peptides are interchangeable. Its relatives GHRP-6, GHRP-2 and hexarelin each have their own entries with far more human data.
At a Glance
Every value in this table is printed from the Grey Peptides dataset, the same record the compound explorer and comparison tool read, so the three can never disagree.
Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, 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.
Published Research
These are the studies of alexamorelin read from their PubMed abstracts on October 29, 2026: the one study that gave it to people, a liver-cell metabolism study, and five anti-doping papers. The anti-doping papers' titles name the peptide class, not alexamorelin; they are carded because each abstract names it among the peptides tested.
Hormone responses in six young adults
Intravenous alexamorelin at 1.0 and 2.0 micrograms per kilogram raised growth hormone and prolactin just as hexarelin did, in step with dose. ACTH and cortisol rose with both peptides, significantly more after the higher alexamorelin dose, and aldosterone rose only with alexamorelin. A 20 mg oral dose raised growth hormone a little more than oral hexarelin, a difference that was not significant.
What human liver cells turn it into
Software predicted 21 possible metabolites, but after three hours with liver cells pooled from ten donors only one appeared: hexarelin, made by removing the terminal alanine, while alexamorelin itself fell about 150-fold. Because hexarelin is sold in its own right, its presence cannot prove alexamorelin use, so testers still need the parent peptide.
First urine test for the GHRP family
A doping-control method extracted eight growth hormone-releasing peptides, alexamorelin among them, from human urine and detected them intact by liquid chromatography-mass spectrometry, with detection limits of 0.2 to 1 ng/mL.
What rats excrete
Rats were dosed orally and intravenously with eight GHRPs including alexamorelin, and 28 urinary metabolites, at least three per peptide, were identified, then checked against human serum. The abstract notes that apart from GHRP-2 none of these peptides is an approved drug, yet all were readily available online.
One screen for horses and athletes
A high-throughput method extracts and derivatises eight GHRPs, alexamorelin among them, from horse and human urine; all eight or their metabolites were detected in urine from rats given them intravenously.
Direct-injection screening
A urine method using ion-mobility mass spectrometry covers 18 prohibited small peptides including alexamorelin, at 50 to 500 pg/mL; urine should be stored at −20 °C.
Blood spots, serum and plasma
A single-step method detects 54 prohibited compounds in dried blood spots, serum and plasma. All were stable for two months frozen, but at 4 °C and 22 °C alexamorelin was among those extensively degraded within a week in serum and plasma; in dried blood it stayed detectable.
Side Effects & Contraindications
Reported Side Effects
From the one human study; no adverse events are described in its abstract.
Contraindications & Cautions
There is no label; these cautions follow from the single study and its legal status.
Legal Status
Alexamorelin was never developed into a medicine.
Frequently Asked Questions
?What is alexamorelin?
A synthetic seven-amino-acid growth hormone-releasing peptide, hexarelin with an extra alanine at the front, that acts on the ghrelin receptor.
?Has it been tested in people?
Once. A 2000 study gave single doses to six young adults to measure hormone responses. No treatment trial has ever been run.
?How does it compare with hexarelin?
In that study it raised growth hormone and prolactin as much as hexarelin, but raised ACTH and cortisol more at the higher dose and also raised aldosterone. In human liver cells it is converted into hexarelin.
?Is there a dose?
Only the amounts from that one endocrine test, 1 and 2 micrograms per kilogram intravenously and 20 mg by mouth, given once. They were chosen to measure hormone responses, not to treat anything.
?Is it banned in sport?
Yes. WADA lists it among the prohibited growth hormone-releasing peptides, and doping laboratories test for it in urine and blood.
References
- [other] PubChem CID 10011122, Alexamorelin: formula C50H63N13O7, molecular weight 958.1. Read October 28, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/10011122
- [clinical-trial] Broglio F, et al. "Endocrine activities of alexamorelin (Ala-His-d-2-methyl-Trp-Ala-Trp-d-Phe-Lys-NH2), a synthetic GH secretagogue, in humans." Eur J Endocrinol, 2000;143(3):419-25. PMID: 11022186.
- [pubmed] Pobee E, et al. "Identification of alexamorelin consumption biomarkers using human hepatocyte incubations and high-resolution mass spectrometry." J Anal Toxicol, 2025;49(6):394-400. PMID: 40465419.
- [pubmed] Thomas A, et al. "Determination of growth hormone releasing peptides (GHRP) and their major metabolites in human urine for doping controls by means of liquid chromatography mass spectrometry." Anal Bioanal Chem, 2011;401(2):507-16. PMID: 21298258.
- [pubmed] Thomas A, et al. "Metabolism of growth hormone releasing peptides." Anal Chem, 2012;84(23):10252-9. PMID: 23101768.
- [pubmed] Timms M, et al. "A high-throughput LC-MS/MS screen for GHRP in equine and human urine, featuring peptide derivatization for improved chromatography." Drug Test Anal, 2014;6(10):985-95. PMID: 24574167.
- [pubmed] Thomas A, et al. "Simplifying and expanding the screening for peptides <2 kDa by direct urine injection, liquid chromatography, and ion mobility mass spectrometry." J Sep Sci, 2016;39(2):333-41. PMID: 26578461.
- [pubmed] Mazzarino M, et al. "Rapid and harmonized analytical workflow for the determination of peptidic and non-peptidic doping agents in dried and liquid blood matrices." Analyst, 2026. PMID: 42328738.
Sources & Citations
Every study on this page was read from its PubMed record on October 29, 2026. The sequence is from the 2000 study's title and the formula and weight from PubChem. No seller's figure is used. 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. Consult a licensed healthcare provider before making health decisions.