Ipamorelin

NNC 26-0161, Ipamorelin acetate, "Ipa" (community shorthand); CAS 170851-70-4

Checked Oct 28, 2026

The short answer

No human evidence yet for body composition, recovery and sleep in healthy adults

For the uses people buy it for, grade D: animal data only, and no human trial has measured body composition, recovery or sleep.

Approved?: Not approved for any use.
Safety: C, thinly characterized: The one published trial called short IV courses well tolerated, but FDA's reviewers noted two deaths among patients given IV ipamorelin after bowel surgery and said it was unclear whether the deaths were related to the drug.

We tried it. This is what happened.

Tesamorelin and ipamorelin: water was the ceiling PausedI ran the growth-hormone pair with strict timing, cut the dose when the water came, and stopped when it would not leave.

The full answer: what it is for, the dose, the units

What people take it for: People take it to raise their own growth hormone for leaner body composition, faster recovery and better sleep, usually together with CJC-1295.

Does it work for body composition, recovery and sleep in healthy adults? D, no human evidence yet. Result: not tested in humans.

For the uses people buy it for, grade D: animal data only, and no human trial has measured body composition, recovery or sleep. The only human efficacy trials tested it for gut recovery after bowel surgery and did not show a benefit.

No approval for any use.

Highest evidence for any use: A for recovery of bowel function after bowel resection (two randomized placebo-controlled Phase 2 trials; the published one did not meet its primary endpoint).

Safety: C, thinly characterized. The one published trial called short IV courses well tolerated, but FDA's reviewers noted two deaths among patients given IV ipamorelin after bowel surgery and said it was unclear whether the deaths were related to the drug. There is no long-term human safety data at self-injected doses.

Do not use if: Reasonably avoided by anyone with active or prior malignancy, during pregnancy/breastfeeding, in children/adolescents (open growth plates), and used cautiously with diabetes/insulin resistance.

Could it be placebo? No controlled trial for body composition, recovery or sleep exists, so a placebo effect cannot be ruled out for those uses.

The dose people use, and the units to draw

Sources disagree: Andrew Huberman called 100 micrograms or less per night an interesting tool, a 2026 review lists forum use of 200 to 300 mcg subcutaneously 2 or 3 times a day, and the hospital trials gave 0.03 to 0.06 mg/kg by IV. None is a validated self-injection protocol.

Source	Dose	How often and how	Who it was for	Link
Beck et al. 2014, Phase 2 randomized placebo-controlled trial	0.03 mg/kg	Intravenous infusion twice daily from postoperative day 1 until day 7 or discharge	117 adults after small or large bowel resection; primary endpoint time to tolerate a solid meal (25.3 h ipamorelin vs 32.6 h placebo, p = 0.15)	Abstract, methods and results
NCT01280344, Phase 2 randomized double-blind placebo-controlled dose-finding trial (registry record)	0.03 mg/kg or 0.06 mg/kg per infusion	Intravenous; arms of 0.03 mg/kg twice daily, 0.06 mg/kg twice daily and 0.06 mg/kg three times daily, versus placebo	320 adults after small or large bowel resection; completed May 2014, no results posted or published that we found	Arms and interventions section
Gobburu et al. 1999, dose-escalation study in healthy volunteers	4.21, 14.02, 42.13, 84.27 and 140.45 nmol/kg	Single intravenous infusion over 15 minutes per dose level	8 healthy men per dose level; measured pharmacokinetics (half-life about 2 hours) and the GH response (peak at 0.67 hours), not any health outcome	Abstract
Andrew Huberman, Huberman Lab (host remark on guest episode)	100 mcg or less per night	Per night; no route or duration stated in the quote	General remark about the compound as a tool; not a trial population	Chapter 00:46:35 'Ipamorelin, GHRP-6, Sleep, Appetite'; auto-transcript segment near 54:01 of the audio file, verify by ear
Dominikowski et al., Front Endocrinol 2026, review Table 2 (forum-use entry)	200 to 300 mcg	Subcutaneous, 2 or 3 injections a day timed to mimic natural GH pulses, often with CJC-1295 (no DAC); cycles of 8 to 12 weeks on, 4 to 6 weeks off	Self-directed use reported on bodybuilding-related forums; the review states these regimens are not clinically validated	Table 2, ipamorelin row, bodybuilding-forums entry

Named sources range from 100 mcg or less per night (Huberman) to 200 to 300 mcg subcutaneously, 2 or 3 times a day (Frontiers review of forum use), and the only trials used 0.03 to 0.06 mg/kg intravenously in hospital patients.

Dr. Abud Bakri (Huberman Lab, June 2026) names ipamorelin in the secretagogue discussion at about 133:21 with no dose (auto-transcript). Peter Attia's April 2026 peptide AMA (show notes visible only in part, remainder members-only) gave no ipamorelin dose that we could see. Examine has no page we could open. The earlier once-daily bedtime schedule on the site had no named source, and the guest on the Huberman episode, Dr. Craig Koniver, also gave doses but runs a peptide practice, so his figures are not used.

Reported by the named source, never prescribed by us.

How many units do I draw?

Use the calculator: units on the syringe = (dose in mg divided by vial mg) times water mL times 100 for a U-100 syringe. Open the dose calculator

Why it might work

Subcutaneous injection
Ipamorelin (a synthetic pentapeptide
GHS-R1a receptor activation
The peptide selectively binds the ghre
Pulsatile GH release
GHS-R1a activation triggers a short
Hepatic IGF-1 elevation
Circulating GH reaches the liver
Downstream tissue effects (assumed)
Elevated GH and IGF-1 are assumed to p

Assumed pathway, not shown in people.

Assumed mechanism (not an approved drug): ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) that selectively activates the ghrelin / growth-hormone-secretagogue receptor (GHS-R1a), a G-protein-coupled receptor on the anterior pituitary. This triggers a short, pulsatile release of the body's own growth hormone, which in turn raises IGF-1. Its selling point is selectivity, in trials it did this without meaningfully raising cortisol, prolactin, or ACTH. The downstream body-composition and recovery benefits people seek are inferred from GH/IGF-1 biology, not directly demonstrated.

The trials, claim by claim

Result tags: the two bowel-surgery trials were randomized and placebo-controlled, so the claim is graded A; the published trial missed its main goal, and the second has no posted results.

Ipamorelin is a selective growth-hormone secretagogue that raises GH without significantly raising ACTH, cortisol, or prolactin, the core mechanistic claim.

Demonstrated in the foundational animal/in-vitro work (Raun et al., 1998, rat pituitary cells, rats, swine) and consistent with its receptor selectivity; GH-raising effect also observed in human PK/PD work. Selectivity is well-supported mechanistically but the cleanest data are preclinical.

Raun 1998, first selective GH secretagogue (PubMed)

Ipamorelin improves a clinically meaningful human outcome.

Result: did not work

The strongest human test (Phase 2 RCT for postoperative ileus, ~117 patients) was NEGATIVE: authors reported it 'did not shorten the time to first meal intake' and showed 'no significant difference in measurable colonic functions' vs placebo. A second, larger randomized placebo-controlled Phase 2 (n=320, NCT01280344) completed in 2014 with no results posted or published. This is a rare case where human RCT data exists and argues against efficacy for the tested endpoint.

Beck et al., Int J Colorectal Dis 2014, phase 2 ipamorelin for postoperative ileus (PMID 25331030)

Ipamorelin builds muscle, reduces fat, or slows aging in humans.

Result: not tested in humans

No controlled human trial has tested these outcomes. Body-weight/lean-mass effects are documented only in animals. The popular use case is an extrapolation from short-term GH pulses, not a measured human result.

Ipamorelin clinical trials registry (ClinicalTrials.gov)

Status

Ipamorelin is not FDA-approved and is not an established prescription therapy.

Ipamorelin is not FDA-approved for any indication. It is sold as a 'research peptide' and is in FDA's Category 2 for 503B outsourcing facilities (immunogenicity and serious-event concerns), and an FDA advisory committee voted 12 to 0 against adding it to the 503A bulks list in 2024. Any therapeutic use is off-label/gray-market.

FDA, certain bulk drug substances that may present significant safety risks (Category 2)

Status

In 2024 an FDA advisory committee voted 12 to 0, with one abstention, against adding ipamorelin (free base and acetate) to the 503A bulks list.

Regulatory fact from final summary minutes. Advisory vote, not a rule; it goes on the access axis, not a grade, and says nothing about efficacy.

FDA final summary minutes, PCAC Oct 29, 2024

Risks and the label warnings

Adverse events

In trials and clinic reports, adverse effects are usually mild: injection-site irritation, headache, transient dizziness/lightheadedness (possible brief blood-pressure dip), fatigue, nausea, and mild fluid retention (tingling/puffy hands or ankles) at higher GH exposure. The one published Phase 2 trial (117 post-surgery patients, IV dosing) described it as well tolerated, but FDA's review noted two deaths among treated patients, said it was unclear whether they were related to ipamorelin, and noted more low potassium, insomnia and high blood sugar at discharge. The larger 320-patient trial has no posted results.

Contraindications

Reasonably avoided by anyone with active or prior malignancy, during pregnancy/breastfeeding, in children/adolescents (open growth plates), and used cautiously with diabetes/insulin resistance. The FDA flagged immunogenicity (immune reaction to the peptide) as a concern for this class. The single largest practical risk is product quality: unregulated 'research-only' vials with uncertain purity, dose, sterility, or contaminants.

Theoretical concerns

Anything that repeatedly stimulates the GH/IGF-1 axis carries theoretical concerns: insulin resistance / impaired glucose tolerance, fluid retention, joint aches, and, over the long term and unstudied at these doses, the general worry that chronically elevated IGF-1 could promote growth of existing tumors. As a ghrelin-receptor agonist it can also influence appetite. None of this is established as harmful at reported microgram doses, but none of it is reassured by long-term human data either.

What nobody knows yet

No long-term human safety data at the doses people actually use; no human data at all for the body-composition/anti-aging use case; unknown effects of years of intermittent GH pulsing; and unknown real-world content of gray-market product. The honest unknown is large.

What else could explain the result

Ipamorelin is very rarely taken alone, it is almost always combined with CJC-1295 (and frequently alongside TRT/testosterone, tesamorelin, BPC-157, GLP-1 agonists, or an aggressive diet-and-training block). A bedtime routine also coincides with sleep, so 'better sleep/recovery' is hard to separate from simply having a nighttime routine. Attribution to ipamorelin specifically is therefore weak.

Is the vial what it says?

Cross-checked the foundational pharmacology (Raun 1998, PubMed 9849822), two Helsinn Phase 2 trials (NCT00672074 n=117; NCT01280344 n=320) on ClinicalTrials.gov, the negative proof-of-concept publication (Beck et al. 2014, Int J Colorectal Dis), and regulatory status (non-FDA-approved, compounding-restricted). Community/clinic dosing and side-effect reports were read against, and discounted relative to, the peer-reviewed and registry sources; vendor pages were treated as non-evidence.

Half-life and storage

Half-life: Terminal elimination half-life is approximately 2 hours in humans, with rapid clearance.

Once mixed: Supplied as a lyophilized powder; reconstituted with bacteriostatic water. Sensitive to handling: add diluent slowly down the vial wall, swirl gently, do not shake or vortex (agitation degrades peptide). Lyophilized vials are stable long-term frozen/cold; once reconstituted, refrigerate at 2-8 C and use within roughly 3-4 weeks. Avoid heat excursions and avoid re-freezing the reconstituted solution. Keep on an interior fridge shelf, not the door.

What I noticed, and what people report

Case study

Tesamorelin and ipamorelin: water was the ceiling PausedI ran the growth-hormone pair with strict timing, cut the dose when the water came, and stopped when it would not leave.

What people report

Volume of reports: moderate. A real body of reports, fairly consistent.

High volume of discussion, ipamorelin (usually as 'CJC-1295/Ipamorelin') is one of the most widely used and talked-about GH peptides across bodybuilding, biohacking, TRT, and anti-aging-clinic communities, with extensive forum threads and clinic marketing.

Moderately consistent on the subjective side: users commonly report better sleep and recovery, mild fat loss, and gradual lean-mass/skin improvements over weeks-to-months. But reports of dramatic effects are inconsistent, a meaningful minority report 'felt nothing,' and almost all positive reports come from people also running CJC-1295 and/or other compounds, so the consistency is in the narrative, not in clean attribution.

Mixed-to-low source credibility. A large share of favorable content is from peptide vendors, compounding pharmacies, and wellness clinics with a financial interest (discounted here). Independent, non-commercial user reports exist and skew 'mild, gradual, subtle' rather than transformative, and notably the one rigorous human readout (the postoperative-ileus RCT) was negative, which should anchor expectations more than forum sentiment.

Anecdote, not proof: the most common report is improved sleep quality and quicker workout recovery within the first few weeks, often described as subtle rather than dramatic.
Many users report gradual changes in body composition (slightly leaner, better skin, modest lean-mass gains) over 2-3+ months, almost always while also running CJC-1295 and usually alongside training/diet changes.
A recurring minority report little or no perceptible effect, and some note tolerance or diminishing returns over time.
Mild, transient complaints show up regularly: head-rush or lightheadedness right after injection, occasional water retention or tingling in the hands, and head/face flushing; most call it well tolerated at low doses.

Reports are anecdote, not proof.

Can you tell if it is working?

Partly trackable

Serial DEXA (lean/fat-free mass + VAT) is the single best objective readout, but ipamorelin's human efficacy is unproven, so expect small-or-null and treat any positive as the real signal; the wearable deep-sleep channel was cut as too speculative and too noisy to verify.

Bloodwork

Partly measurableConfidence: Plausible

A lab moves, but it's noisy, indirect, or off-target, treat it as a hint, not proof.

Ipamorelin is a selective GHS-R1a (ghrelin receptor) agonist that triggers pulsatile pituitary GH release. GH itself is too pulsatile and short-lived to catch on a spot draw, but it drives hepatic IGF-1, which integrates the GH signal into a more stable serum level that routine LabCorp/Quest assays measure. So the drug's action shows up indirectly via IGF-1, but only PARTIALLY: at the common low subcutaneous "peptide clinic" doses the integrated IGF-1 rise is often modest and can sit within assay/biologic noise, and there is no human trial establishing a reliable IGF-1 elevation for ipamorelin specifically. IGF-1 also tracks the drug's proximal hormonal action, not any clinical outcome.

IGF-1IGF-1 serum (routine, LabCorp/Quest)

A clear rise above the patient's own pre-dose baseline, ideally toward the upper end of the age/sex reference range. The only trustworthy signal is a within-person increase over a standardized baseline, no fixed target number, and a flat result at low doses does not rule out GH pulses.

GH secretagogues raise hepatic IGF-1, the standard integrated readout for the GH axis. It is the correct marker, but for short-acting, low-dose ipamorelin the movement is often small and noisy, so it is only a partial verifier of the drug's hormonal action, and not a verifier of muscle/fat/recovery benefit.

Draw baseline

before first dose (morning draw; standardize the clock time since IGF-1 is only mildly diurnal, and hold diet/fasting state constant)

Retest

6-8 weeks

Read this before you spend on labs

IGF-1 is the correct routine, integrated marker for a GH secretagogue, but treat it as a PARTIAL verifier, not proof. (1) Do NOT order a random/spot GH level, GH is pulsatile and short-lived, so a single draw is uninterpretable; IGF-1 is why you don't chase GH. (2) Ipamorelin is short-acting and selective, so at common low subcutaneous doses the IGF-1 bump is frequently modest and can fall within assay/biologic noise; only a change against a true, standardized pre-dose baseline is trustworthy, and a flat result does not prove the drug did nothing. (3) Human evidence is thin, the foundational data is animal-only and no human trials have measured body-composition or recovery outcomes for ipamorelin, so a rise in IGF-1 confirms only that the GH axis is being stimulated, not any downstream benefit. IGFBP-3 was dropped: it is GH-dependent but less sensitive and redundant, so if IGF-1 is borderline it adds nothing.

Raun et al. 1998, Eur J Endocrinol, Ipamorelin, the first selective growth hormone secretagogue (PMID 9849822)

Other ways to track it

DEXA scanIndirect / noisy

DEXA scan, total and appendicular lean/fat-free mass, plus fat mass and visceral adipose tissue (VAT)

If the GH -> IGF-1 axis does anything anabolic for you, it shows up here as a small gain in lean/fat-free mass and possibly a modest drop in fat/VAT over months. Two honest caveats: (1) early fat-free-mass gains on GH secretagogues are partly fluid retention, not muscle, so the first read can overstate the effect; (2) ipamorelin's own human body-composition data is animal-only, so a flat DEXA is common and expected, it does not mean the scan or the protocol failed. No reliable magnitude to promise.

Ipamorelin's marketed benefit is GH -> IGF-1 -> anabolic tone, and DEXA is the instrument sensitive enough to catch lean-mass and VAT change if that pathway works for you. Class precedent, not proof: the same-class oral ghrelin mimetic MK-677 raised fat-free mass by ~1.1 kg vs placebo on DEXA at the 1-year body-composition endpoint of a randomized trial (Nass 2008, Ann Intern Med; the 2-year arm was a safety continuation), but that is a related compound, not ipamorelin, and the same trial showed rising fasting glucose/HbA1c, a metabolic cost rather than a benefit.

Baseline before starting, retest at 12-16 weeks (DEXA precision needs a real interval; sooner is dominated by fluid and measurement noise). Same scanner, same fasted/hydration state each time.How to do it right

Bottom line

Ipamorelin has no controlled human trial proving it changes body composition, sleep, or recovery, those uses rest on mechanism plus anecdote (Ground Truth grade D), and its only rigorous human RCTs (postoperative ileus) were negative. So nothing here is a validated direct proof. The honest play is to define objective baselines you can actually verify, serial DEXA for lean mass/VAT (strongest, backed only by same-class MK-677 data) plus IGF-1 on blood (partial), then judge on a pre-set threshold over 12-16 weeks and accept that a flat result is the most likely outcome. Wearable deep-sleep was dropped: there is no controlled ipamorelin sleep data, the physiology runs slow-wave-sleep -> GH rather than clearly the reverse, and consumer deep-sleep staging is too noisy to count as evidence. Note that a rising fasting/CGM glucose in this class is a side effect, not efficacy, so do not read it as the peptide 'working.'

Logging baseline vs retest is the whole game. The Truth Tracker is our free log for bloodwork, DEXA, genetics, and wearable data, bring your own numbers.

How to track it

History

First documented human use: Human pharmacokinetic/pharmacodynamic dosing was characterized in healthy volunteers by 1999 (Gobburu et al.), and the first published randomized controlled human trial was Helsinn Therapeutics' Phase 2 postoperative-ileus study (NCT00672074, results published Beck et al., Int J Colorectal Dis, December 2014). Critically, NO controlled human trial has ever tested ipamorelin for the body-composition, recovery, sleep or anti-aging outcomes for which it is actually marketed.

1998Raun et al. (Novo Nordisk) publish ipamorelin as 'the first selective growth hormone secretagogue' (NNC 26-0161) in animal/in-vitro models. European Journal of Endocrinology.
Late 1990s-2000sHuman PK/PD dosing characterized; terminal half-life ~2 hours. Novo Nordisk does not advance it as an approved GH product.
2008-2014Helsinn Therapeutics runs Phase 2 trials for postoperative ileus: NCT00672074 (~117 patients) and the larger NCT01280344 (~320 patients), IV dosing.
December 2014Beck et al. publish the proof-of-concept RCT: ipamorelin did NOT significantly improve bowel-function recovery vs placebo (Int J Colorectal Dis).
~2015 onwardNo further clinical development is published after the failed ileus trial; ipamorelin migrates into the gray-market 'research peptide' / wellness-clinic space, usually stacked with CJC-1295.
2023-2026FDA lists ipamorelin acetate in Category 2 (significant safety risk) for outsourcing facilities. Its advisory committee voted 12 to 0, with one abstention, against adding it to the 503A bulks list on Oct 29, 2024. It was not among the peptides reviewed in July 2026.

All sources

Raun et al. 1998, 'Ipamorelin, the first selective growth hormone secretagogue' (PubMed 9849822)(Foundational pharmacology; animal/in-vitro; establishes GH selectivity vs ACTH/cortisol/prolactin.)
Beck et al., Int J Colorectal Dis 2014, phase 2 ipamorelin for postoperative ileus (PMID 25331030)(Proof-of-concept Phase 2 RCT in bowel-resection patients; NEGATIVE on primary endpoint.)
Ipamorelin Phase 2 trial NCT00672074 (ClinicalTrials.gov)(Helsinn, ~117 patients, IV, postoperative ileus; completed, no results posted; program later discontinued.)
Ipamorelin Phase 2 trial NCT01280344 (ClinicalTrials.gov)(Helsinn, ~320 patients, multiple IV dose arms, GI dysmotility; completed 2014, no results posted.)
All ipamorelin trials (ClinicalTrials.gov search)(Confirms human trials are limited to GI-motility indications; none for body composition/anti-aging.)
Gobburu et al., Pharm Res 1999, PK/PD of ipamorelin in human volunteers (PMID 10496658)(Human pharmacokinetics and pharmacodynamics in healthy volunteers; IV infusions.)
FDA, certain bulk drug substances that may present significant safety risks (Category 2)(Lists ipamorelin acetate in Category 2 for 503B outsourcing facilities.)
FDA final summary minutes, PCAC Oct 29, 2024(Advisory committee voted 12 no, 0 yes, 1 abstention on listing ipamorelin for 503A.)
Huberman Lab, 'Dr. Craig Koniver: Peptide & Hormone Therapies for Health, Performance & Longevity', Oct 7, 2024. Huberman: 'ipamorelin at a 100 micrograms dosage or less per night sounds like it's an interesting tool.'(dose table)
Dominikowski A, et al. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis. Front Endocrinol 2026;17:1822475. doi:10.3389/fendo.2026.1822475, PMID 42395176(dose table)
Beck DE, et al. Int J Colorectal Dis 2014. PMID 25331030(dose table)
ClinicalTrials.gov NCT01280344, arm group descriptions(dose table)
Gobburu JV, et al. Pharm Res 1999. PMID 10496658(dose table)

Not medical advice. Grades reflect the evidence as of the date above and will change as data arrives. Reports from users are anecdote, not proof. Talk to a licensed clinician before you act on anything here.