Summary
Ipamorelin is a five amino acid ghrelin receptor agonist (it activates the receptor for the hunger hormone ghrelin) developed in the 1990s as a growth hormone secretagogue, a drug that makes the pituitary release growth hormone, that unlike GHRP-2 and GHRP-6 does not raise cortisol or prolactin in animals. The only randomized human trial tested it for postoperative ileus (the gut stalling after bowel surgery) and found no significant benefit. One small pharmacology study showed a single IV (into a vein) infusion releases GH in healthy men, but there is no human trial of ipamorelin for GH deficiency, body composition, recovery, or sleep, which are the uses it is sold for. FDA placed it on the 503A Category 2 list (compounding ingredients flagged for significant safety risks) in September 2023, the nominators withdrew it in 2024, and it is now listed as a withdrawn nomination with no lawful basis for compounding (custom-making by a pharmacy).
What is Ipamorelin?
Ipamorelin is a synthetic pentapeptide growth hormone secretagogue; selective agonist at the ghrelin receptor (GHS-R1a). It is also known as Ipamorelin acetate, NNC 26-0161, Aib-His-D-2-Nal-D-Phe-Lys-NH2, CJC-1295/ipamorelin blend.
How does it work?
Ipamorelin binds the growth hormone secretagogue receptor (GHS-R1a, the ghrelin receptor) on pituitary somatotrophs and hypothalamic neurons, triggering GH release through a pathway separate from GHRH. In rats and pigs its potency and efficacy for GH release matched GHRP-6, but it did not raise ACTH, cortisol, prolactin, LH, FSH, or TSH even at doses 200 fold above the GH ED50. Ghrelin receptor activation also stimulates gastric motility, which is why it was later tested for postoperative ileus.
| Cluster | Metabolic and growth hormone axis |
|---|---|
| Routes | Subcutaneous injection (as sold, no human pharmacokinetic publication); Intravenous infusion (human ileus trial); Intranasal (anti-doping metabolite study only) |
| Conditions studied | Growth hormone deficiency and GH secretagogue use |
| Record | v4, draft, verified Sep 23, 2026 |
Ipamorelin benefits: what the evidence shows
For the uses ipamorelin is marketed for (GH release for muscle, fat loss, recovery, anti-aging, sleep) the evidence is animal and in vitro only: rat, pig, and cell studies show selective GH release and rat studies show increased bone growth. The one randomized, double blind, placebo controlled human trial (n = 117) tested intravenous ipamorelin for postoperative ileus and found no significant difference from placebo in time to first tolerated meal (25.3 versus 32.6 hours, p = 0.15); it did show the drug was well tolerated over up to 7 days. Development stopped after that trial. One small human pharmacology study (40 healthy men, five IV infusion rates) found GH release at every dose, but no human study reports GH, IGF-1, or body composition outcomes with the subcutaneous doses sold today. That trial used intravenous ipamorelin for a surgical indication, not the subcutaneous product as marketed; it is listed but does not raise the grade.
| Evidence type | Indexed studies | Participants (human) |
|---|---|---|
| Human randomized trials | 1 | 117 |
| Human observational studies | 1 | 40 |
| Animal studies | 3 | n/a |
| All indexed studies | 5 | 157 |
Human evidence
Beck 2014 (Ipamorelin 201 Study Group): 117 adults enrolled after small or large bowel resection, 114 analyzed, randomized to 0.03 mg/kg intravenous ipamorelin or placebo twice daily on postoperative days 1 to 7. Median time to first tolerated solid meal was 25.3 hours with ipamorelin versus 32.6 hours with placebo (p = 0.15); secondary endpoints also did not differ. Treatment emergent adverse events occurred in 87.5% of the ipamorelin group and 94.8% of placebo, with no safety signal. A 1999 dose escalation study in 40 healthy men found that a single 15 minute IV infusion released GH at all five infusion rates, with a terminal half-life of about 2 hours; no published trial measures GH or IGF-1 responses to the subcutaneous doses used outside research. No indexed human trial for GH deficiency, body composition, or sleep identified.
Animal evidence
Raun 1998: in rat pituitary cells ipamorelin released GH with potency similar to GHRP-6; in anesthetized rats and conscious pigs it released GH with comparable efficacy while, unlike GHRP-2 and GHRP-6, not raising ACTH or cortisol. Johansen 1999: ipamorelin increased longitudinal bone growth in rats. Venkova 2009 and Greenwood-Van Meerveld 2012: ipamorelin accelerated gastric emptying and reversed delayed transit in rodent models of postoperative ileus, which motivated the human trial.
Key studies
| Study | Design and population | Outcome | Grade |
|---|---|---|---|
| Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients2014 PMID 25331030 | Multicenter, randomized, double blind, placebo controlled phase 2 trial, intravenous dosing up to 7 daysn = 117 Adults after open or laparoscopic small or large bowel resection | Median time to first tolerated meal 25.3 hours versus 32.6 hours with placebo (p = 0.15); no significant difference on any efficacy endpoint; well tolerated | Evidence: Human RCT evidence |
| Ipamorelin, the first selective growth hormone secretagogue1998 PMID 9849822 | In vitro rat pituitary cell assays plus in vivo studies in anesthetized rats and conscious pigsRat pituitary cells, rats, and pigs | GH release comparable to GHRP-6 (pig ED50 2.3 nmol/kg) with no increase in ACTH, cortisol, prolactin, LH, FSH, or TSH | Evidence: Animal-only evidence |
| Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats1999 PMID 10373343 | Controlled animal studyRats | Increased longitudinal bone growth and IGF-1 related markers with repeated dosing | Evidence: Animal-only evidence |
| Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus2009 PMID 19289567 | Controlled animal studyRats with surgically induced postoperative ileus | Ipamorelin accelerated gastric emptying and intestinal transit, motivating the later human trial | Evidence: Animal-only evidence |
| Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers1999 PMID 10496658 | Dose escalation pharmacokinetic and pharmacodynamic study, five IV infusion ratesn = 40 Healthy men (8 per dose level) | A single 15 minute IV infusion released GH at all dose levels, with a single GH peak at about 0.67 hours and a terminal half-life of about 2 hours; no clinical or body composition outcome | Evidence: Human observational evidence |
Conditions studied
| Condition | Grade | Note |
|---|---|---|
| Growth hormone deficiency and GH secretagogue use | Evidence: Animal-only evidence | Human data are single dose pharmacology studies and an intravenous postoperative ileus trial that do not raise the grade for the marketed use; development stopped; listed by FDA as a withdrawn 503A nomination since April 2026. |
Is Ipamorelin legal in the United States?
FDA and compounding status
Not FDA approved for any use and never approved anywhere. FDA placed ipamorelin (free base and acetate) on the 503A Category 2 list on September 29, 2023, citing immunogenicity risk, peptide related impurities, and lack of safety data for the compounded routes. The nominators withdrew the 503A nominations in September 2024 and FDA's April 2026 update moved it to the list of nominated but withdrawn substances rather than Category 1 or the bulks list. Ipamorelin acetate also remains in 503B Category 2 (added September 29, 2023) on the FDA page current as of April 22, 2026. It was not among the peptides the Pharmacy Compounding Advisory Committee reviewed in July 2026. Because it has no active nomination, is not on the 503A bulks list, and is not a component of an approved drug, licensed 503A pharmacies and 503B outsourcing facilities have no lawful basis to compound it.
WADA status
WADA prohibited. Athletes subject to anti-doping testing should treat this as prohibited at all times unless the current prohibited list says otherwise.
Regulatory timeline
- WADA
WADA publishes the 2027 Prohibited List
WADA published the 2027 Prohibited List on September 21, 2026, and it takes effect January 1, 2027. The S2 peptide hormone and growth factor classes are unchanged. BPC-157 is still named under S0, and MOTS-c is still named under S4.4 as an activator of AMP-activated protein kinase. WADA added a note that many peptides without approval for human use fall under S0 or another section, and that a peptide not named on the list may still be prohibited. GLP-1 receptor agonists such as semaglutide and tirzepatide are still not on the list.
- FDA
FDA lists BPC-157 and 16 other peptides as withdrawn from 503A Category 2
FDA's Category 2 page, revised in April 2026 and current as of April 22, 2026, moved BPC-157, AOD-9604, CJC-1295, dihexa, DSIP, epitalon, injectable GHK-Cu, ipamorelin, KPV, LL-37, melanotan II, MOTS-c, PEG-MGF, selank, semax, thymosin alpha-1, and thymosin beta-4 fragment (TB-500) to a list of bulk drug substances nominated but withdrawn by their nominators. A withdrawn substance is no longer in 503A Category 2, but withdrawal is not an approval and does not place a substance on the 503A bulks list; a 503A pharmacy still needs a listing before it may compound it. Ipamorelin acetate remains in 503B Category 2. Seven of the withdrawn peptides (BPC-157, KPV, TB-500, MOTS-c, semax, epitalon, and DSIP) were taken to the Pharmacy Compounding Advisory Committee in July 2026.
- WADA
WADA 2026 Prohibited List takes effect
The 2026 WADA Prohibited List took effect on January 1, 2026 and continues to prohibit the S2 peptide hormone and growth factor classes (GHRH analogs, growth hormone secretagogues, GH fragments, IGF-1 and analogs, MGF, thymosin beta-4 and derivatives, hCG and GnRH-class releasing factors in males), myostatin inhibitors, insulin and the AMPK activator MOTS-c under S4, desmopressin under S5, and BPC-157 under S0. GLP-1 receptor agonists such as semaglutide and tirzepatide are not on the list.
- WADA
WADA 2025 Prohibited List keeps peptide hormones and growth factors banned at all times
The 2025 WADA Prohibited List took effect on January 1, 2025. Section S2 (peptide hormones, growth factors, related substances and mimetics) covers GHRH analogs such as CJC-1295, sermorelin, and tesamorelin, growth hormone secretagogues such as ipamorelin, GHRP-2, GHRP-6, hexarelin, and ibutamoren (MK-677), growth hormone fragments such as AOD-9604, growth factors including IGF-1 and its analogs, MGF, and thymosin beta-4 (TB-500), and chorionic gonadotropin and releasing factors such as gonadorelin and kisspeptin (prohibited in males). Myostatin inhibitors such as ACE-031 fall under S4, insulin under S4 metabolic modulators, desmopressin under S5, and BPC-157 remains an S0 non-approved substance.
- FDA
FDA places GHRP-2, GHRP-6, and ipamorelin in 503B Category 2
On September 29, 2023 FDA added growth hormone releasing peptide-2 (GHRP-2, for injectable and nasal routes), GHRP-6, and ipamorelin acetate to Category 2 under the 503B interim policy, citing immunogenicity risk from aggregation and peptide related impurities and, for GHRP-2, reports of serious adverse events. Outsourcing facilities may not compound a substance while it is in 503B Category 2. All three remain listed on the FDA page current as of April 22, 2026.
- FDA
FDA places a batch of nominated peptides in 503A Category 2
In September 2023 FDA updated its 503A bulk drug substances category lists to place a group of nominated peptides in Category 2, which means FDA identified significant safety risks and the substances may not be used in 503A compounding while the evaluation continues. Kisspeptin-10 and ibutamoren (MK-677) were added on September 29, 2023 and remain in Category 2 on the FDA page current as of April 22, 2026. BPC-157, CJC-1295, ipamorelin, AOD-9604, dihexa, DSIP, epitalon, KPV, MOTS-c, selank, semax, melanotan II, LL-37, thymosin alpha-1, and thymosin beta-4 fragment (TB-500) were also placed in Category 2 under the 503A interim policy; that same page now lists them as nominated but withdrawn (see the April 2026 event). Hexarelin, PNC-27, and 5-amino-1MQ have never appeared on the FDA category lists.
What published studies of Ipamorelin used
Ranges below are reported from published studies and labeling only. PeptideAgent does not recommend doses or protocols.
Not established in human literature for GH related use. The only human RCT used 0.03 mg/kg intravenously twice daily for up to 7 days for postoperative ileus. Animal GH release studies used nanomole per kilogram intravenous doses (rat ED50 about 80 nmol/kg; pig ED50 about 2.3 nmol/kg). No human dose finding study for subcutaneous ipamorelin has been published.
Routes reported
| # | Route |
|---|---|
| 1 | Subcutaneous injection (as sold, no human pharmacokinetic publication) |
| 2 | Intravenous infusion (human ileus trial) |
| 3 | Intranasal (anti-doping metabolite study only) |
Ipamorelin side effects
Side effects
| # | Reported side effect |
|---|---|
| 1 | No safety signal versus placebo in the 7 day intravenous ileus trial (adverse events 87.5% versus 94.8%, mostly surgical) |
| 2 | Injection site reactions, headache, flushing, and lightheadedness reported anecdotally |
| 3 | Increased appetite (ghrelin receptor effect) reported anecdotally |
| 4 | FDA cited immunogenicity risk from aggregation and impurities and limited safety data by the routes used in compounding when it placed ipamorelin in Category 2 |
| 5 | Theoretical GH and IGF-1 related effects (fluid retention, insulin resistance, growth of existing tumors) untested in humans at marketed doses |
Interactions
| # | Interaction |
|---|---|
| 1 | No formal human interaction studies exist |
| 2 | Glucocorticoids and somatostatin analogs blunt GH release from any secretagogue |
| 3 | Diabetes medications: GH raises glucose, so a theoretical effect on insulin requirements exists |
| 4 | Often sold blended with CJC-1295; the combination has never been tested in humans |
Contraindications
| # | Contraindication |
|---|---|
| 1 | Active malignancy (GH and IGF-1 are growth promoting; no human safety data) |
| 2 | Pregnancy and breastfeeding (no data) |
| 3 | Competitive athletes subject to WADA testing (named in section S2) |
How do people access Ipamorelin legally?
Typical cost: Not available through licensed channels. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity.
Verified access options
Step 1
Not legally available through a licensed pharmacy (no active 503A nomination, not on the bulks list, not an approved drug).
Step 2
Clinics that still advertise compounded ipamorelin are dispensing outside FDA's stated categories; ask what the legal basis is.
Step 3
Products labeled research use only are not lawful for human use.
Access paths are verified against public regulatory records and prescriber licensing. We never list unlicensed vendors.
Compare Ipamorelin
What's actually offered, and what that means for you
Licensed compounding pharmacies, clinics, and telehealth prescribers openly offer many unapproved peptides, and prescribers write prescriptions for them. That does not make ipamorelin lawful. Ipamorelin is not FDA approved and not on the 503A bulks list, so a pharmacy has no lawful basis to compound it. [6] [10]
Enforcement is uneven. FDA mostly acts through warning letters to compounders and online sellers, Category 2 safety listings, and import alerts that let it detain shipments, rather than stopping every pharmacy. State pharmacy boards oversee pharmacies day to day, and their rules differ. [10] [11] [12] [13] [14]
What changes for you
- No FDA review of the product: FDA does not check a compounded drug's safety, effectiveness, or quality before it is sold. [14]
- Identity, purity, sterility, and dose accuracy can vary from batch to batch. [10]
- Insurance rarely covers it, so you usually pay cash.
- For tested athletes, ipamorelin is prohibited at all times on the WADA list, whatever the source. [8]
What to check
These checks lower some risks, but they do not make an unlawfully compounded product lawful or safe. Check for:
- A 503A pharmacy licensed in your state (your state board of pharmacy publishes license lookups). [14]
- A real evaluation by a licensed prescriber, not just an online form.
- A certificate of analysis for the specific batch.
Blends that contain Ipamorelin
Ipamorelin is sold in premixed blends under the names below. No blend has been tested as a combination, and a mix is only as lawful as its least lawful ingredient.
- CJC-1295 and ipamorelin: with CJC-1295. No lawful path.
- Sermorelin and ipamorelin: with Sermorelin. No lawful path.
- Tesamorelin and ipamorelin: with Tesamorelin. No lawful path.
Frequently asked questions
What is ipamorelin?
Ipamorelin is a synthetic five amino acid peptide that activates the ghrelin receptor (the receptor for the hunger hormone ghrelin) and makes the pituitary gland release growth hormone. Developed in the 1990s, it was described as the first selective growth hormone secretagogue (growth hormone releaser) because in animals it released growth hormone without raising cortisol or prolactin. In people it was tested only for bowel recovery after surgery, where it did not help, and it has never been approved. [1] [2]
Is ipamorelin legal in the United States?
It is not an FDA approved drug and cannot lawfully be compounded. FDA put ipamorelin on the 503A Category 2 list (substances with significant safety risks) in September 2023, the companies that nominated it withdrew those nominations in 2024, and in April 2026 FDA moved it to the list of withdrawn nominations. That is not a listing on the 503A bulks list, so pharmacies have no legal basis to compound it. Possession is not a crime, but research chemical versions are not lawful for human use. [6] [7]
Ipamorelin benefits: what does the evidence show?
Nobody has tested it. In rats and pigs ipamorelin releases GH about as well as GHRP-6, and in rats it increased bone growth. In humans the only randomized trial tested it for bowel recovery after surgery, not body composition, and it was negative. One small study found a single IV infusion releases GH in healthy men, but no published trial measures GH, IGF-1, muscle, or fat changes from the subcutaneous doses sold today, so PeptideAgent grades the evidence for the marketed uses animal-only. [1] [2] [3] [9]
What are the side effects of ipamorelin?
In the only human RCT, 7 days of intravenous ipamorelin after bowel surgery produced no more adverse events than placebo (87.5% versus 94.8%, mostly surgical). Anecdotal reports with subcutaneous use mention injection site reactions, headache, flushing, lightheadedness, and increased appetite. FDA's Category 2 evaluation flagged immunogenicity risk from peptide aggregation and impurities. Long term effects of raising GH this way in adults are unstudied. [1] [6]
How much does ipamorelin cost?
There is no lawful licensed channel, so there is no legitimate price. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity. [6]
Is ipamorelin banned by WADA?
Yes. Ipamorelin is named in section S2 of the WADA Prohibited List under growth hormone secretagogues (with GHRP-2, GHRP-6, hexarelin, and ibutamoren) and is prohibited at all times. Anti-doping laboratories have published methods to detect it and its metabolites in urine. [5] [8]
Ipamorelin vs CJC-1295: what is the difference and why are they combined?
They act on different receptors. Ipamorelin is a ghrelin receptor agonist; CJC-1295 is a long acting GHRH analog. In theory activating both pathways releases more GH than either alone, which is why clinics sold them blended, but that combination has never been tested in a human trial. CJC-1295 has small human RCTs showing sustained GH and IGF-1 increases; ipamorelin has only one small IV pharmacology study of GH release in healthy men. Both were placed in Category 2 in 2023 and both are now withdrawn nominations, so neither can be lawfully compounded. [2] [6] [9]
Why is ipamorelin called the cleanest GH secretagogue?
Because of the 1998 animal pharmacology. In pigs, GHRP-2 and GHRP-6 raised ACTH and cortisol along with GH, while ipamorelin released GH without raising ACTH, cortisol, prolactin, LH, FSH, or TSH, even at very high doses. That selectivity is real in animals, but it has not been confirmed in a human trial at the doses people use. [2]
Decisions about starting, stopping, or combining any treatment belong with a licensed clinician who knows your history.
From the blog
- Tesamorelin vs sermorelin vs ipamorelin: evidence and legality
Tesamorelin, sermorelin, and ipamorelin compared in one table: mechanism, FDA approval, compounding status, human evidence, and WADA status, with links to each pairwise comparison.
- Does tesamorelin build muscle? What the trials show
Tesamorelin raised lean body mass about 1.2 kg in HIV trials and slightly increased trunk muscle area, but no trial tested strength or muscle growth, and it is prohibited in sport.
- Peptide stacks: what each common component has shown alone
No trial has tested a multi-peptide stack for muscle growth or fat loss. Nine common stack components ranked by their own human evidence, legal status, and WADA status. No protocols.
- Peptides for muscle growth, ranked by human evidence
MK-677, sermorelin, tesamorelin, CJC-1295, IGF-1 LR3, and more ranked by human evidence. None is approved for muscle growth, and all ten are banned in tested sport.
- Tesamorelin prescription: who qualifies and how to get one
How to get tesamorelin legally: who qualifies for Egrifta WR on label, how off-label prescribing works, why compounded tesamorelin is not lawful, what a visit should check, and cost.
- What is peptide therapy? What clinics sell, what is legal, and what works
Peptide therapy means three different things: FDA-approved drugs, compounded prescriptions, and research-only products. Here is how to tell them apart, what the evidence shows, and what it costs.
Sources
Numbered citations above point to these primary sources. PubMed entries link to the indexed abstract.
- [1]Beck DE, Sweeney WB, McCarter MD; Ipamorelin 201 Study Group. Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis 2014PubMed 25331030, 2014
- [2]Raun K et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol 1998PubMed 9849822, 1998
- [3]Johansen PB et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res 1999PubMed 10373343, 1999
- [4]Venkova K et al. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. J Pharmacol Exp Ther 2009PubMed 19289567, 2009
- [5]Semenistaya E et al. Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, hexarelin, and ipamorelin. Drug Test Anal 2015PubMed 25869809, 2015
- [6]FDA: Bulk drug substances used in compounding under section 503A of the FD&C Act (503A bulks list, Category 1, 2, and 3 lists, and withdrawn nominations)FDA, 2026
- [7]FDA Pharmacy Compounding Advisory Committee meetings (July 2026 meeting on peptide nominations)FDA, 2026
- [8]WADA Prohibited List, section S2 (growth hormone secretagogues, including ipamorelin)WADA, 2026
- [9]Gobburu JV et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res 1999PubMed 10496658, 1999
- [10]FDA: Certain bulk drug substances for use in compounding may present significant safety risks (Category 2)FDA
Cite this page
Free to cite and quote with a link. Data is licensed CC BY 4.0 with attribution to PeptideAgent.
- APA style
PeptideAgent. (2026, September 23). Ipamorelin: evidence, legality, and access. https://peptideagent.ai/peptides/ipamorelin- HTML link
<a href="https://peptideagent.ai/peptides/ipamorelin">Ipamorelin: evidence, legality, and access</a>, PeptideAgent, updated September 23, 2026.