Ipamorelin

The Ipamorelin evidence base cited here is 6 sources — 2 clinical, 2 preclinical, 1 review. Its strongest evidence is human — 2 clinical studies, most recently 2014 ("Ipamorelin for Post-Operative Ileus — Phase II Trial"). Regulatory status: Not FDA-approved.

• Ipamorelin is a five-amino-acid growth hormone secretagogue (GHRP) that triggers GH release by acting on the ghrelin receptor (GHS-R1a) — not by adding GH directly.
• Its signature trait is selectivity: unlike older GHRPs (GHRP-6, GHRP-2), it raises GH without meaningfully spiking cortisol, prolactin, aldosterone, or appetite-driving ghrelin at therapeutic doses.
• It amplifies the body's natural pulsatile GH rhythm and is most effective dosed at bedtime, riding the natural nocturnal GH surge; pairs synergistically with a GHRH analog (CJC-1295 / Mod GRF 1-29).

Ipamorelin is a synthetic pentapeptide in the growth-hormone-secretagogue (GHRP) class, first developed by Novo Nordisk in the 1990s for growth-hormone-deficiency research. It's one of the most popular GH-optimization peptides, used for recovery, body composition, sleep, and anti-aging goals.

Its claim to fame is a clean selectivity profile — it nudges GH up without the cortisol, prolactin, and hunger surges that dog earlier GHRPs. Worth keeping in perspective, though: the mechanism is well-characterized, but rigorous human efficacy data for the body-composition uses people actually buy it for is limited. It's not FDA-approved and is banned in sport. Everything below is research context, not medical advice.

Ipamorelin is a five-residue peptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2, ~712 Da) that mimics ghrelin to stimulate GH release. It belongs to the GHRP family, but is distinguished by how narrowly it acts. Pharmacokinetically it peaks around 40 minutes after a subcutaneous dose, has a ~2-hour half-life, and is largely cleared within ~10 hours (Raun et al., 1998).

Where GHRP-6 and GHRP-2 also drive appetite (via ghrelin activity) and can raise cortisol and prolactin, ipamorelin largely sticks to GH release alone at normal doses. That cleaner profile is the main reason it became the go-to GHRP for people pairing a secretagogue with a GHRH analog.

No FDA-approved dosing exists. The figures below come from research rationale and community use, included for research context only. The only published human trial used 7 days of continuous dosing — the longer cycles below are extrapolated.

• Standard range: 100–200 mcg per dose, once or twice daily.
• Beginner: 100 mcg once daily before bed for 8–12 weeks (bedtime is the single most effective window).
• Intermediate: 100–200 mcg twice daily (morning + bedtime) for 8–12 weeks.
• Advanced: 200 mcg 2–3× daily, often with a GHRH analog (CJC-1295), for 8–12 weeks.
• Cycling: commonly 8–12 weeks on, 4–8 weeks off to limit receptor desensitization.

Take on an empty stomach (≥30 min before food or ~2 hours after) — elevated glucose and insulin blunt the GH response. The pre-bed dose rides the natural nocturnal GH surge. Note a saturation effect: GH release is roughly maximal around ~100 mcg, so larger single doses add little — which is why split dosing (2–3×/day) is preferred over one big shot.

Given by subcutaneous injection — abdomen, thigh, or deltoid, with sites rotated to avoid lipodystrophy. Abdominal SC is usually the most convenient and least painful.

• Reconstitute the lyophilized powder with bacteriostatic water; draw the dose into a fine insulin syringe (29–31 g).
• Pinch a skin fold, insert at 45–90°, depress slowly, withdraw, dispose of the needle safely.
• Rotate injection sites each time.

• Weeks 1–2: improved sleep quality and mild energy increase; some report more vivid dreams (enhanced REM).
• Weeks 3–4: noticeably better exercise recovery and reduced muscle soreness.
• Weeks 6–8: gradual body-composition shifts (less subcutaneous fat, fuller muscle), reported skin-quality gains.
• Weeks 10–12: more pronounced composition changes, strength gains, improved joint comfort.
• Weeks 12–16+: cumulative benefits peak; some note hair/nail improvements.

These are user reports — response varies widely with age, baseline GH levels, diet, training, and genetics. Not validated in controlled human body-composition trials.

The mechanistic and selectivity science is solid; human efficacy data for the popular uses is the weak point.

• Selectivity (the landmark finding): in the original work, ipamorelin released GH dose-dependently without affecting ACTH, cortisol, prolactin, or TSH — even at doses up to 100 mcg/kg.
• Bone: aged-rat studies showed increased bone mineral content and bone-formation markers.
• Comparative GHRP studies confirmed it produced the most specific GH release with the fewest off-target hormone effects.

Combinations aren't formally studied. Research context, not protocol advice. Usual approach: keep standard ipamorelin dosing and add complementary peptides.

• Ipamorelin + CJC-1295 (no DAC) / Mod GRF 1-29 — the most popular pairing; GHRH primes, ipamorelin amplifies, for greater combined GH release. Often equal amounts (e.g. 100 mcg each) dosed together.
• Ipamorelin + BPC-157 — systemic GH-driven recovery plus localized tissue repair.
• Ipamorelin + Tesamorelin — pairs a GHRP with an FDA-approved GHRH analog, aimed at enhanced abdominal-fat reduction.

• Reconstitute lyophilized powder with bacteriostatic water added slowly down the vial wall; swirl gently, never shake. Solution should be clear and colorless.
• Example: 5 mg + 5 mL BAC water = 1 mg/mL (1000 mcg/mL); a 200 mcg dose = 0.2 mL (20 units on an insulin syringe).
• Unreconstituted: stable 12+ months at room temp or refrigerated. Reconstituted: 2–8°C, use within ~4–6 weeks; never freeze; protect from light/heat.
• Use bacteriostatic (not sterile) water for multi-dose vials to inhibit bacterial growth.

Generally well-tolerated; most effects are mild and transient, and the selectivity profile means fewer hormone-driven side effects than other GHRPs.

Most effects fade as the body adjusts; starting low and titrating up minimizes early discomfort.

• Not FDA-approved for any indication; classified as a research chemical in the US, legal to buy 'for research' but not for human consumption.
• The FDA has sent warning letters to companies marketing peptides like ipamorelin for human use; selling it as a supplement or therapeutic is prohibited.
• Possession for personal use isn't explicitly criminalized in most US states.
• International: prescription-only (Schedule 4) in Australia; sale restricted in the UK though possession isn't criminalized. Verify your jurisdiction — rules evolve.

Ipamorelin is banned by WADA under S2 (peptide hormones, growth factors, mimetics), both in- and out-of-competition. It applies to Olympic, professional, collegiate, and many amateur athletes, with detection windows extending several days post-dose. Any tested athlete should assume use will produce a positive test and sanctions — treat it as strictly off-limits.

On the Huberman Lab podcast, Dr. Abud Bakri grouped ipamorelin among the higher-fidelity GH secretagogues — cleaner than older GHRPs, with less of the hunger, prolactin, and cortisol activity seen with ghrelin agonists like MK-677. He noted that a tesamorelin + ipamorelin combination can drive IGF-1 into puberty-level ranges, which is also why appetite and insulin-sensitivity effects (and the general GH cautions) still apply.

He repeatedly stressed that GH secretagogues are inexpensive (under ~$100) relative to growth hormone itself, which fuels their popularity — while the long-term safety of chronically elevating GH/IGF-1 remains genuinely unknown (his recurring 'is there a free lunch?' question).

Expert commentary; the secretagogue category is not FDA-approved and the long-term GH/IGF-1 safety question is unresolved.

All citations link to the original source (PubMed, journal site, or regulatory filing). Independent research database — no vendor influence on what's cited.