Ipamorelin side effects: what the trials, the FDA and the TGA recorded

Evidence limits

What do the safety records for ipamorelin not show?

The FDA's summary says that Gobburu et al. (1999), a study in eight healthy men at each of five infusion rates that measured hormone levels, did not state whether adverse events occurred; that reporting gap does not establish that none occurred (FDA briefing document, 29 October 2024).

A 2020 review of this class of compounds names the same limit. It describes a 'paucity of data' on their clinical effects, and it ran no new trial (Sinha et al., Translational Andrology and Urology, 2020).

What side effects have been recorded in people given ipamorelin?

In the placebo-controlled Phase 2 trial in 114 analysed bowel-surgery patients, any treatment-emergent adverse event occurred in 87.5 percent of patients given ipamorelin and 94.8 percent given placebo, and the authors said most events were mild to moderate and generally related to surgery or the underlying disease (Beck et al., 2014). In those 114 patients, nausea, vomiting and abdominal swelling were the most common events and were similar between groups, in one small trial in postoperative patients (Beck et al., 2014). In the same 114 bowel-surgery patients, low potassium (12.5 against 3.4 percent), sleeplessness (10.7 against 5.2 percent) and high blood sugar at discharge (14.3 against 8.6 percent) were more common with ipamorelin than with placebo, and one small postoperative trial cannot separate a drug effect from surgery (Beck et al., 2014; FDA briefing document, 29 October 2024). In that trial of 114 bowel-surgery patients, three patients on each arm stopped treatment because of an adverse event; a small postoperative trial cannot separate a drug effect from surgery (FDA briefing document, 29 October 2024, describing Beck et al.).

In the 2014 trial of 114 analysed patients who had just had bowel surgery, the authors concluded that ipamorelin was well tolerated over up to 7 days and did not differ significantly from placebo on the key and secondary efficacy measures; that conclusion is the authors' own and applies to postoperative patients only (Beck et al., 2014).

The comparison table below sets out the full set of figures the FDA reported from this trial.

What serious adverse events did the trial record?

In the Phase 2 trial in 114 analysed bowel-surgery patients, serious adverse events occurred in 10 patients (17.9 percent) given ipamorelin and 9 (15.5 percent) given placebo, including infection, anastomotic leak (where a surgical join between bowel ends fails) and readmission within 30 days; a small postoperative trial cannot separate a drug effect from surgery (FDA briefing document, 29 October 2024, describing Beck et al., 2014). In that trial of 114 bowel-surgery patients, two patients given ipamorelin died, both after bowel resection for colon cancer with postoperative complications, and the FDA said it is unclear whether the deaths were related to ipamorelin (FDA briefing document, 29 October 2024). The FDA said the deaths, together with the higher rates of low potassium and high blood sugar in the small trial of 114 analysed bowel-surgery patients, weighed in its safety concern, although it was unclear whether ipamorelin played a part in the deaths (FDA briefing document, 29 October 2024).

The FDA's account of the trial of 114 analysed bowel-surgery patients gives the primary causes of death as high potassium (in a patient with aortic clots), sepsis, a perforated ulcer, and renal failure with sepsis (in a patient with pneumonia), and says most serious events occurred after patients had finished therapy; a trial of 114 patients cannot separate a drug effect from the surgery (FDA briefing document, 29 October 2024).

What did the FDA conclude about the safety of compounded ipamorelin?

The FDA concluded in its August 2024 review that compounding with ipamorelin may raise safety concerns. The review lists the adverse events from the one surgery trial, flags a risk that peptide impurities or clumping could provoke an immune response, and notes that ipamorelin contains unnatural amino acids that complicate characterisation. It found no safety data for the subcutaneous route, and it could not conclude that ipamorelin avoids concerns seen with approved products that raise growth hormone, such as glucose intolerance and diabetes (FDA briefing document, 29 October 2024).

The review also says that, because ipamorelin acts on the ghrelin receptor, it may have behavioural reinforcing properties that can contribute to addiction, and may negatively affect reproductive health and pregnancy outcomes. These are the FDA's concerns from the mechanism and nonclinical data, not harms measured in a trial (FDA briefing document, 29 October 2024).

Two adverse event reports reached the FDA through 30 September 2023. One followed a nasal spray product, with increased tear production and headache that the report assumed related to a product quality issue (FDA briefing document, 29 October 2024). The other followed a compounded product that also contained sermorelin, with joint pain that the FDA could not link to ipamorelin specifically (FDA briefing document, 29 October 2024).

The FDA's advisory committee voted 0 yes, 12 no, 1 abstain on adding ipamorelin to the 503A bulks list on 29 October 2024 (FDA final summary minutes). Is ipamorelin legal in Australia? covers the regulatory records.

What does the FDA say about ipamorelin, GHRP-6 and similar compounds?

The FDA's category 2 page lists ipamorelin acetate and GHRP-6 for the 503B pathway, both added on 29 September 2023. For GHRP-6 the FDA cites immunogenicity risk plus 'potential effect on cortisol and increase in blood glucose due to decreases in insulin sensitivity'. For ipamorelin acetate it cites immunogenicity risk, unnatural amino acids, and a published study of intravenous ipamorelin in a gastric-motility setting. The trial figures in the FDA's briefing document, from 114 analysed bowel-surgery patients, are in the sections above. The FDA adds that it lacks information on harm by other routes (FDA category 2 page, content current as of 22 April 2026).

The same page lists GHRP-2 and ibutamoren mesylate. The FDA lists them as category 2 substances, and this page reports no trial result for either one (FDA category 2 page). The tesamorelin, sermorelin, GHRP-6 and ipamorelin comparison sets the class side by side. A listing here is a regulator's safety flag, not a measured rate of harm.

Is ipamorelin safer than HGH?

No comparison of the safety of ipamorelin with human growth hormone was found in the sources read for this page, so none supports calling it safer. In a pig study with no count in the abstract, ipamorelin released growth hormone without raising ACTH or cortisol above the GHRH level, which is an animal result that does not establish a human result and is not a safety finding in people (Raun et al., European Journal of Endocrinology, 1998). In the FDA's view, no data show that ipamorelin avoids concerns seen with approved products that raise growth hormone, such as glucose intolerance and diabetes (FDA briefing document, 29 October 2024). The TGA delegate noted in 2015 that risks from misuse of these substances are considered similar to those of growth hormone misuse (TGA, March 2015).

In eight healthy men at each of five infusion rates, growth hormone rose to a single short peak and then fell to negligible levels; the study measured hormone levels, not safety (Gobburu et al., 1999). The FDA flagged that prolonged exposure might run down growth hormone stores in people with partial deficiency, which is a concern drawn from that model and not a measured harm (FDA briefing document, 29 October 2024). Neither point is a safety comparison with the hormone itself.

What are the side effects of tesamorelin, and is there safety data on a tesamorelin and ipamorelin blend?

No safety data on a tesamorelin and ipamorelin blend were found: a PubMed search on 14 October 2026 returned seven records for both names, all review articles, and ClinicalTrials.gov returned no study that lists both. Tesamorelin has its own record. The Egrifta WR label, revised March 2025, lists warnings for neoplasms (new tissue growth), raised IGF-1, fluid retention, glucose intolerance, hypersensitivity and reactions where the medicine is given, and lists joint pain, pain in the limbs and peripheral swelling among its most commonly reported adverse reactions; its initial US approval year is 2010 (Egrifta WR label, March 2025). In a 26-week trial in 412 adults with HIV, adverse events did not differ significantly from placebo, though more people on tesamorelin withdrew because of one; that result applies to tesamorelin alone in that group and not to a blend (Falutz et al., New England Journal of Medicine, 2007).

That makes the evidence uneven. Tesamorelin has a 26-week trial in 412 adults with HIV (Falutz et al., 2007) and an approved label for one condition (Egrifta WR label, March 2025). The published ipamorelin trial with quantified adverse-event results found in the searches for this page followed 114 analysed bowel-surgery patients for up to 7 days (Beck et al., 2014). Neither record covers the two together, and a combined product also carries the manufacturing and purity questions the FDA raised for compounded peptides. How tesamorelin and ipamorelin differ sets out the comparison.

What does PubMed show about ipamorelin clinical trial safety?

A PubMed search for ipamorelin on 14 October 2026 returned 55 records, and only two are indexed as clinical trials: the 1999 volunteer study and the 2014 surgery trial. The FDA's review says Gobburu et al. (1999), a hormone-level study in healthy male volunteers, did not state whether adverse events occurred; that reporting gap does not establish safety (FDA briefing document, 29 October 2024). Beck et al. (2014), a trial in 114 analysed bowel-surgery patients, is the only source of adverse-event rates found in these searches. A second Phase 2 trial, NCT01280344, enrolled 320 patients and shows no posted results on ClinicalTrials.gov, so its safety findings are unpublished in the sources opened for this page (PubMed and ClinicalTrials.gov, 14 October 2026).

The rest of the PubMed record is animal work, laboratory studies and reviews. A 2026 review states that the clinical evidence for ipamorelin remains minimal, and it ran no new trial (Dominikowski et al., Frontiers in Endocrinology, 2026). The record can change, and the search date above is the one that applies.

What adverse events has the TGA recorded for unapproved peptide products?

The TGA's advisory of 13 April 2026 lists adverse events and other concerns it has received for unapproved peptide products as a group: severe allergic reactions needing adrenaline and hospital care, a severe whole-body inflammatory response needing hospital management, itching, palpitations, pain and sweating, insomnia, blurred vision, extreme tiredness, flu-like illness, joint pain, skin sensitivity, musculoskeletal injuries including plantar fasciitis and Achilles tendinitis, and poor product quality. The advisory names BPC-157, GHK-Cu, TB-500, retatrutide and CJC-1295 as examples and does not name ipamorelin in the text read, so the list is not a rate for ipamorelin (TGA safety advisory, 13 April 2026).

That makes this a record about a category, not a rate for ipamorelin. The TGA says unapproved peptide products have not been assessed for safety, quality or effectiveness, and that important information about them remains unknown. Peptide side effects in general covers the wider evidence.