Lower numbers = closer to natural. Higher numbers = more enhanced.
Why this rating?
Per Raun et al. 1998 (PMID 9849822), Ipamorelin is the first truly selective GH secretagogue, unlike GHRP-2/6, it does not significantly raise ACTH or cortisol even at doses 200x the effective GH-releasing dose, and has no meaningful effect on prolactin, FSH, LH or TSH. EC50 = 1.3 nmol/L with Emax = 85% (vs. GHRP-6). It is synergistic with GHRH analogs like CJC-1295 (no-DAC)/Mod GRF via the classic complementary GHRP+GHRH mechanism, though the "2-10x GH / 1.5-3x IGF-1" figures sometimes quoted for that stack actually come from a study of the different, long-acting CJC-1295 WITH DAC used alone (Teichman et al. 2006, PMID 16352683), not the Ipamorelin pairing. WADA-prohibited (S2), confirming performance relevance. Rated 4, consistent with the other GH secretagogues in this scale. It enhances natural GH with the cleanest side effect profile of all GHRPs, but stays ceilinged by what the pituitary can produce.
Overview
A synthetic pentapeptide and the first truly selective growth hormone secretagogue. Unlike GHRP-2 and GHRP-6, ipamorelin does not significantly raise cortisol, ACTH, or prolactin - even at doses 200x higher than the effective dose for GH release. This makes it the "cleanest" GHRP with the best side effect profile, commonly stacked with CJC-1295 for synergistic GH elevation.
Important Warnings
- •Not FDA approved for any human use
- •WADA prohibited - will cause positive drug test
- •Must inject on empty stomach - food blunts GH release
- •Research chemical status means quality varies between sources
- •Helsinn Therapeutics' Phase II trial of Ipamorelin for postoperative ileus was discontinued due to lack of efficacy
- •FDA placed Ipamorelin in Category 2 of its bulk drug substances list in 2023, restricting licensed compounding pharmacies from producing it; in April 2026 the FDA removed it from Category 2 after the original safety-concern nomination was withdrawn, referring it for further Pharmacy Compounding Advisory Committee review - it remains unapproved for human use, some state pharmacy boards continue to restrict it, and most supply still comes from unregulated research-chemical vendors
- •Limited peer-reviewed data on bodybuilding/performance outcomes. Human data is largely limited to short pharmacokinetic studies, not chronic dosing trials
Purpose & Use Cases
Growth Hormone Release
Stimulates pulsatile GH release with a single peak at ~40 minutes post-injection (Gobburu et al. 1999, PMID 10496658). Synergistic with GHRH analogs like CJC-1295 (no-DAC)/Mod GRF 1-29 through complementary receptor mechanisms, amplifying the GH pulse well beyond either peptide alone.
Fat Loss
Enhanced lipolysis through increased GH, particularly effective for visceral/abdominal fat. Noticeable results at 6-8 weeks.
Recovery Enhancement
Stimulates IGF-1 production for muscle hypertrophy, protein synthesis, and connective tissue regeneration. Often stacked with BPC-157 or TB-500 for injuries.
Anti-Aging
Improved skin elasticity, better sleep quality, increased energy. Significant results at 3-6 months.
Benefits
- Most selective GHRP - does NOT raise cortisol, ACTH, or prolactin
- Minimal appetite stimulation (unlike GHRP-6)
- Cleanest side effect profile of all GHRPs
- GH peak at ~40 minutes post-injection
- Synergistic with CJC-1295 (GHRH analog)
- Improves sleep quality when dosed pre-bed
- Supports fat loss and body recomposition
- Well-tolerated even at high doses
Good to Know
The cleanest, most selective GHRP
Ipamorelin's defining feature: unlike GHRP-2 and GHRP-6, it does not meaningfully raise cortisol, ACTH or prolactin, even at doses far above what is needed for GH release. That selectivity is why it is the default GHRP for most modern protocols.
A secretagogue: stimulates your own GH
It binds the GHS-R1a (ghrelin) receptor to trigger a pulsatile GH release from your own pituitary and a downstream IGF-1 rise. It is not exogenous GH, works within physiological feedback, and does not suppress the testosterone axis.
Minimal appetite: good for cutting
Because it is far less ghrelin-active on hunger circuits than GHRP-6 (the 'hunger peptide'), Ipamorelin causes little appetite spike, making it the preferred GHRP when dieting.
Synergistic with a GHRH analog
Paired with CJC-1295 (no DAC)/Mod GRF 1-29, GH release is synergistically amplified well beyond either peptide alone, because GHRH and GHRP act through complementary mechanisms. (The often-cited "2-10x GH / 1.5-3x IGF-1 for 6-11 days" figures actually describe the different, long-acting CJC-1295 WITH DAC used ALONE, Teichman et al. 2006, PMID 16352683: not this typical no-DAC pairing.)
Inject fasted, no PCT
Food and the insulin it raises blunt the GH pulse, so dose on an empty stomach (pre-bed dosing also aligns with the largest natural nocturnal pulse). No PCT is ever required.
Dosage Guidelines
| Experience Level | Dosage Range |
|---|---|
| Beginner | 100 – 200 mcg/day |
| Intermediate | 200 – 300 mcg/day |
| Advanced | 300 – 300 mcg/day |
Standard protocol: 200-300mcg per injection, 1-3x daily. Space injections 6-8 hours apart. Commonly stacked with CJC-1295 (100-150mcg) per injection. Inject fasted - food blunts GH release. 4-week break between cycles recommended.
Side Effects
Headaches
uncommonOccasional headaches reported, usually transient.
Stay hydrated. Usually resolves with continued use.
Flushing
uncommonTemporary facial flushing or warmth after injection.
Normal response, resolves within minutes.
Injection Site Irritation
uncommonRedness or mild irritation at injection site.
Rotate injection sites.
Water Retention
rareMinimal compared to other GHRPs. Related to GH/IGF-1 elevation.
Usually minor and transient.
Numbness/Tingling
rareTransient numbness or tingling occasionally reported.
Typically resolves on its own.
General Mitigation Strategies
Ipamorelin has the cleanest side effect profile of all GHRPs. Unlike GHRP-2 and GHRP-6, it does NOT increase cortisol, ACTH, or prolactin - even at very high doses. Minimal appetite stimulation makes it suitable for cutting. Most users experience very few side effects.
Post Cycle Therapy (PCT)
Does not affect HPT axis. No PCT required.
How It Works
Ipamorelin selectively binds to and activates GHSR-1a (ghrelin/GHS receptor 1a) in the pituitary gland. This triggers enhanced cyclic adenosine monophosphate (cAMP) production, stimulates GHRH neurons, and directly activates pituitary somatotroph cells to release GH. Unlike other GHRPs, it shows selectivity for GH release similar to GHRH itself - it does not significantly affect ACTH, cortisol, prolactin, FSH, LH, or TSH. EC50 = 1.3 nmol/L with Emax = 85%.
Fundamentals
Reference on the practices relevant to Ipamorelin: how they are done and where they go wrong. Not a recommendation to use it.
Common Stacks
- Ipamorelin + CJC-1295 (no DAC) - Synergistic GH release, most popular stack
- Ipamorelin + Tesamorelin - Tesamorelin as "on switch," Ipamorelin as "volume dial"
- Ipamorelin + BPC-157 + TB-500 - Recovery/healing stack
- Do NOT stack with MK-677 - redundant, increases side effects
Legal Status
Not FDA-approved; sold as a research chemical (USA). WADA prohibited (S2 - GH secretagogue).
Legal status varies by country and changes over time. This is a general summary, not legal advice.
WADA Status
Ipamorelin is prohibited at all times under WADA category S2 as a growth hormone secretagogue.