Ipamorelin Peptide: What It Does, Doses, Evidence

What Is Ipamorelin?

Ipamorelin is a lab-made peptide five amino acids long. It belongs to a family called growth hormone secretagogues, compounds that prompt the pituitary gland to release growth hormone it has already made. It is not growth hormone and it is not a steroid. It copies one action of ghrelin, the stomach hormone best known for hunger, which also happens to be one of the two main signals behind a growth hormone pulse.

It came out of Novo Nordisk in Denmark. In the 1990s its chemists started from an older compound named GHRP-1 and removed pieces to see what still worked. Dropping the two amino acids in the middle left a pentapeptide that released growth hormone about as strongly as GHRP-6, the reference compound of the day. Raun and colleagues published it in 1998 under a title that became its sales pitch: the first selective growth hormone secretagogue.

Raun K, Hansen BS, Johansen NL, et al. "Ipamorelin, the first selective growth hormone secretagogue." European Journal of Endocrinology. 1998;139(5):552-61. Cell, rat, and pig data. View study

Novo Nordisk never brought it to market. The molecule resurfaced a decade later under a different sponsor, Helsinn Therapeutics, for a different job entirely: restarting the gut after bowel surgery. Nearly all of the human exposure comes from that program.

How Ipamorelin Works

Growth hormone release runs on two accelerators and a brake. One accelerator is growth hormone-releasing hormone (GHRH), which tells pituitary cells to make and release GH. The other is the ghrelin receptor, which triggers release through a separate pathway. The brake is somatostatin. Ipamorelin presses the second accelerator. Using blockers of each receptor, the Novo Nordisk team showed it works through the same receptor as GHRP-6 and not through the GHRH receptor.

The growth hormone it releases travels to the liver, which answers with IGF-1, the slower, steadier hormone behind most of what gets attributed to growth hormone. IGF-1 is also why this whole class carries cautions around blood sugar and cancer history. How a secretagogue differs from injecting the hormone itself is covered in peptides vs HGH Read nextPeptides vs HGH: Safety, Cost, and Results ComparedDirect human growth hormone has been around since the 1980s. Growth hormone peptides like Sermorelin, CJC-1295/Ipamorelin, and Tesamorelin are the modern alternative. The two approaches reach the same destination through completely different routes, with very different safety profiles, cost structures, and outcomes. Here is the honest comparison.Read article .

What "Selective" Actually Means

Every ipamorelin page uses the word selective. Few say in which animal. The older secretagogues, GHRP-6 and GHRP-2, released growth hormone but also pushed up ACTH and cortisol, the stress-hormone axis. In conscious pigs, ipamorelin did not. ACTH and cortisol after ipamorelin looked no different from what GHRH itself produced, and that held at doses more than 200 times the dose needed for a half-maximal GH response.

Two details get lost in the retelling. The first is prolactin. It is routinely listed as something ipamorelin avoids, yet in that pig study none of the three compounds moved prolactin, so it was never what set ipamorelin apart. The second is the species. We could not find a published human study that measured cortisol or prolactin after ipamorelin. Selectivity in people is a reasonable expectation from the animal work. It is not a measured result.

Venkova K, Mann W, Nelson R, Greenwood-Van Meerveld B. "Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus." Journal of Pharmacology and Experimental Therapeutics. 2009;329(3):1110-6. Rat study. View study

What the Human Research Actually Shows

Here is the whole published human record as FDA reviewers found it in 2024: one dosing study in healthy men and one trial in surgical patients, both by IV infusion. No published human study has given ipamorelin under the skin, the way every clinic prescribes it, and no trial has measured muscle, fat, sleep, or recovery.

The dosing study came from Novo Nordisk and the University at Buffalo. Healthy men received one of five doses as a 15-minute IV infusion, eight volunteers at each level. Ipamorelin behaved predictably. Blood levels rose in proportion to dose, the terminal half-life was about two hours, and growth hormone came out as a single episode that peaked around 40 minutes and then fell away. FDA reviewers reading the same paper noted that GH was back to very low levels by six hours at every dose.

Gobburu JV, Agersø H, Jusko WJ, Ynddal L. "Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers." Pharmaceutical Research. 1999;16(9):1412-6. Healthy men, IV infusion. View study

Then came the surgical program. Ghrelin-receptor drugs speed up the gut, and after bowel surgery the gut often stalls for days, a problem called postoperative ileus. Helsinn ran a Phase 2 trial in 117 adults having bowel resections, giving 0.03 mg per kilogram by IV twice a day for up to a week. It did not work. Patients on ipamorelin tolerated a solid meal at a median of 25.3 hours against 32.6 hours on placebo, a gap that was not statistically significant, and no secondary measure separated the groups. A larger dose-finding trial, registered with 320 patients, is marked completed with no results posted to ClinicalTrials.gov, and FDA reviewers wrote that development was reportedly discontinued.

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." International Journal of Colorectal Disease. 2014;29(12):1527-34. View study

US Food and Drug Administration. "FDA Briefing Document: Ipamorelin-Related Bulk Drug Substances (Ipamorelin (free base) and Ipamorelin acetate)." Pharmacy Compounding Advisory Committee meeting, October 29, 2024. View study

Ipamorelin Doses: What Studies Used vs What Gets Prescribed

Most searches about ipamorelin are dose searches, so here is the uncomfortable part. No published human study has tested a subcutaneous ipamorelin dose, and FDA reviewers found no pharmacokinetic information for that route. The numbers in circulation have very different pedigrees.

So how much ipamorelin per day? We do not publish a standalone ipamorelin dose, because we do not prescribe standalone ipamorelin. In both of our blends the pharmacy fixes ipamorelin at 2 mg per mL, which works out to 20 mcg in every unit on a U-100 insulin syringe. The partner peptide rides along in a fixed ratio, so a single draw sets both doses.

Your PeRx provider prescribes the protocol, and the label is the final word. The CJC-1295/Ipamorelin dosage chart Read nextCJC-1295/Ipamorelin Dosage Chart: Units & TimingMost CJC-1295 ipamorelin dosage advice online is written in milligrams for a different molecule, or assumes you are juggling two separate vials. PeRx ships one combined vial at a fixed concentration, ready to use. This page converts insulin-syringe units into micrograms of each peptide at that concentration, explains the bedtime and empty-stomach rules, walks through 5-on-2-off and 3-months-on cycling, and prices out a month, as of August 31, 2026.Read article has the full unit-by-unit conversion for that blend, with timing around food and sleep.

Ipamorelin Benefits: What Is Claimed vs What Is Shown

Ipamorelin benefit lists are growth hormone benefit lists with a different name on top. Ipamorelin raises GH, GH does certain things, so ipamorelin is assumed to do them. Only the first link has been measured.

Svensson J, Lall S, Dickson SL, et al. "The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats." Journal of Endocrinology. 2000;165(3):569-77. Rat study. View study

Ipamorelin has been shown to do one thing in humans, which is release a pulse of growth hormone. Everything past that is borrowed, and borrowed does not mean false. What is missing is any measure of how large the effects are or how many people get them. For what realistic change looks like with the paired product, see the CJC-1295/Ipamorelin guide Read nextCJC-1295 Ipamorelin: The Complete GuideCJC-1295 Ipamorelin pairs a GHRH signal that primes growth hormone release with a clean pulse trigger that fires it. After age 30, your body produces roughly 15% less growth hormone every decade. This stack doesn't replace what you've lost with synthetic hormones. It tells your body to start making more of its own again. Together, the two peptides form the most popular growth hormone optimization protocol in peptide therapy.Read article .

Why We Only Prescribe Ipamorelin Paired

If you came here hoping to buy ipamorelin alone, we do not carry it. The reason is physiological. A ghrelin-receptor agonist triggers release, but how much growth hormone is ready to be released depends on the GHRH signal. Work one accelerator and you get a pulse. Work both and the pulse is larger than the two added together.

The evidence for that synergy is real, and it comes with a caveat. In 1990 Bowers and colleagues gave 18 healthy men a growth hormone-releasing peptide, GHRH, or both. Low doses of the two together released more growth hormone than the sum of each alone. The peptide in that study was GHRP-6, ipamorelin's predecessor at the same receptor. No published human study has tested ipamorelin alongside a GHRH analog, so the pairing rests on a shared mechanism and on clinical experience.

Bowers CY, Reynolds GA, Durham D, Barrera CM, Pezzoli SS, Thorner MO. "Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone." Journal of Clinical Endocrinology and Metabolism. 1990;70(4):975-82. Study of GHRP-6, not ipamorelin. View study

We offer two pairings. CJC-1295/Ipamorelin Read nextCJC-1295 Ipamorelin: The Complete GuideCJC-1295 Ipamorelin pairs a GHRH signal that primes growth hormone release with a clean pulse trigger that fires it. After age 30, your body produces roughly 15% less growth hormone every decade. This stack doesn't replace what you've lost with synthetic hormones. It tells your body to start making more of its own again. Together, the two peptides form the most popular growth hormone optimization protocol in peptide therapy.Read article uses the short-acting, no-DAC form of CJC-1295 as the GHRH half, a choice explained in our CJC-1295 guide Read nextCJC-1295 Peptide: What It Is, DAC vs No DACCJC-1295 is a lab-made version of the hormone that tells your pituitary to release growth hormone. The complication is that two different molecules are sold under that one name, one built to last a week and one built to clear quickly, and almost every published human result belongs to only one of them. This guide sorts out which is which, what the evidence covers, and why we had to pick a side.Read article and in why we pair the two Read nextWhy We Pair CJC-1295 With Ipamorelin (No-DAC)CJC-1295 and Ipamorelin act on two different receptors, so together they produce a bigger, cleaner growth-hormone pulse than either one alone. The detail most people miss: we use the no-DAC version of CJC-1295 on purpose. That choice is what keeps the release pulsatile and physiologic instead of a flat, all-day elevation. Here is the reasoning behind the pairing.Read article . Tesamorelin/Ipamorelin Read nextTesamorelin/Ipamorelin: Dosage and Cost (2026)Tesamorelin is the only FDA-approved GHRH analog, and the only GH peptide with Phase 3 trial data on visceral fat. This guide pairs it with Ipamorelin and focuses on what tesamorelin is actually proven to do: shrink deep abdominal fat, lower liver fat, and drive metabolic recomposition. If you want a general GH-support stack, the CJC-1295/Ipamorelin guide covers that. This page is about the FDA-approved, visceral-fat side of the GH peptide world.Read article swaps in tesamorelin Explore PeRxTesamorelinMetabolic Optimization PeptideView peptide , the GHRH analog with Phase 3 trials behind it for abdominal fat in HIV-associated lipodystrophy. For the single-pathway alternative, see ipamorelin vs sermorelin Read nextIpamorelin vs Sermorelin 2026: Which GH Peptide Wins?Both peptides stimulate your pituitary gland to release growth hormone. But they work through different receptors, peak at different speeds, and suit different patients. Here is a direct comparison based on the pharmacology, not marketing.Read article .

Safety and Screening

Day to day, people report the effects that follow from more growth hormone: water retention, tingling or puffy hands, mild headache, and sometimes hunger shortly after a dose. FDA reviewers noted that nothing shows ipamorelin is free of the risks printed on approved growth hormone products, glucose intolerance and fluid retention among them. The blood sugar readings in the surgical trial fit that pattern.

Three unknowns get taken seriously at screening. FDA found no published genotoxicity, reproductive, or carcinogenicity studies of ipamorelin, and called the animal toxicity work that does exist too limited in scope and duration to inform safety. That is why active or recent cancer excludes you, as it does for every peptide that raises GH and IGF-1, and why pregnancy and breastfeeding do too. Separately, because ghrelin receptors also sit in the brain's reward circuits, FDA pharmacologists raised the theoretical possibility of reinforcing effects while noting that no study has shown it. The agency's adverse event database held two non-serious reports through September 2023, which says more about how rarely compounded products get reported than about safety.

FDA and Anti-Doping Status

Where that leaves things: the FDA category document updated May 14, 2026 lists ipamorelin in no 503A category at all, while ipamorelin acetate remains in Category 2 for 503B outsourcing facilities. Its status for pharmacy compounding is unsettled, and we would rather say so plainly. Ipamorelin was not part of the April 2026 action on twelve other peptides and was not on the July 2026 committee agenda. CJC-1295 went through the same process five weeks later with a similar outcome, covered in our CJC-1295 guide Read nextCJC-1295 Peptide: What It Is, DAC vs No DACCJC-1295 is a lab-made version of the hormone that tells your pituitary to release growth hormone. The complication is that two different molecules are sold under that one name, one built to last a week and one built to clear quickly, and almost every published human result belongs to only one of them. This guide sorts out which is which, what the evidence covers, and why we had to pick a side.Read article . Related reading: is CJC-1295/Ipamorelin FDA approved Read nextIs CJC-1295/Ipamorelin FDA Approved? (2026 Answer)The short answer is no. CJC-1295 and Ipamorelin are not FDA-approved drugs. They are compounded medications, prescribed by licensed providers and prepared by regulated pharmacies. Here is what that actually means for you, how it compares to FDA-approved peptides, and why the distinction matters less than most people think.Read article .

US Food and Drug Administration. Summary minutes, Pharmacy Compounding Advisory Committee meeting, October 29, 2024. View study

Anti-doping is clear-cut. The 2026 World Anti-Doping Agency Prohibited List names ipamorelin in section S2.2.4 among the growth hormone secretagogues, next to ibutamoren (MK-677) and ghrelin itself, prohibited at all times. If you compete under WADA, USADA, or a league policy built on that list, ipamorelin is not an option in any blend. Peptide therapy for athletes Read nextPeptide Therapy for Athletes: WADA Rules & UseAthletes were among the earliest adopters of peptide therapy, and for good reason. Faster recovery between training sessions, accelerated injury repair, and improved body composition are directly relevant to athletic performance. But there are rules, and understanding the competitive landscape matters as much as the pharmacology.Read article covers what is and is not permitted.

How to Get Ipamorelin

Ipamorelin reaches people through two channels. Research-chemical sites sell it marked not for human use, with no prescription and no check on what is in the vial. The prescription route runs through a health intake, review by a licensed provider, and a labeled vial from a US 503A compounding pharmacy. Research peptides vs prescription peptides Read nextResearch Peptides vs Prescription Peptides (2026)An honest comparison for the patient who already uses peptides, what the 'Not for Human Use' label actually means, the real quality differences, and the practical steps to switch from research-chemical sourcing to a prescription supply.Read article covers the gap between the two.

CJC-1295/Ipamorelin

No-DAC CJC-1295 at 1.2 mg/mL with ipamorelin at 2 mg/mL in one 5 mL vial, taken as a single evening injection under the skin. From $299 for a one-month supply.

Ipamorelin with a short-acting GHRH analog.

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Tesamorelin/Ipamorelin

Tesamorelin at 3 mg/mL with ipamorelin at 2 mg/mL in one 5 mL vial, the pairing built around the GHRH analog studied for abdominal fat. From $299 for a one-month supply.

Ipamorelin with the GHRH analog that has Phase 3 data.

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Both vials ship fully reconstituted and ready to use, in cold packaging, with insulin syringes and alcohol swabs included. Nothing is charged at checkout. The card on file is billed only after a provider approves the prescription. See where to inject CJC-1295/Ipamorelin Read nextWhere to Inject CJC-1295/Ipamorelin: Sites, TimingCJC-1295/Ipamorelin is a single subcutaneous injection, and for this stack the two decisions that matter most are where you put it and when. The four standard sites all work, but bedtime timing and an empty stomach change the result more than site choice does. Here is the practical guide patients ask for after their first vial arrives.Read article for technique, or the sermorelin, ipamorelin, and tesamorelin comparison Read nextSermorelin vs Ipamorelin vs Tesamorelin: Which Fits?All three raise your own growth hormone, but they pull different levers, last for different amounts of time, and suit different goals. This is a decision guide, not a spec sheet: match the peptide to what you actually want.Read article if you are still choosing.

Ipamorelin: Common Questions

Frieboes RM, Antonijevic IA, Held K, et al. "Hexarelin decreases slow-wave sleep and stimulates the secretion of GH, ACTH, cortisol and prolactin during sleep in healthy volunteers." Psychoneuroendocrinology. 2004;29(7):851-60. Study of hexarelin, not ipamorelin. View study