Growth Hormone Secretagogue (GHRP)

Ipamorelin: Overview, Dosage, Side Effects & Research

A selective growth hormone secretagogue that boosts GH release with minimal side effects — popular for anti-aging and body composition.

Also known as: NNC 26-0161

What is Ipamorelin?

Ipamorelin is a pentapeptide that selectively stimulates growth hormone (GH) secretion from the pituitary gland by activating ghrelin receptors (GHS-R1a). Unlike older GHRPs, it does not significantly increase cortisol or prolactin. This selectivity makes it favorable for body composition improvements, fat loss, muscle preservation, and recovery without the cortisol-related side effects of earlier secretagogues.

Typical Dose
200-300 mcg
Frequency
1–3 times daily (often before bed and/or around workouts)
Half-Life
~2 hours
Administration
Subcutaneous injection
Approval Status
No FDA approval. Research use only.
Legal Status
Research chemical in the US. Not FDA approved. Available through peptide research suppliers.

Dosage Overview

LevelDose
Starting / Low100 mcg
Typical / Maintenance200-300 mcg
Maximum (studied)500 mcg

Commonly dosed at 200–300mcg per injection, 1–3 times daily. Best taken on an empty stomach to maximize GH pulse. Frequently combined with CJC-1295 or GHRH peptides for synergistic effect.

Full dosage guide with titration schedule →

Side Effects

Side EffectFrequency
Transient headacheuncommon
Flushing (face/neck)uncommon
Injection site irritationcommon
Water retention (mild)uncommon
Hunger increase (short-term)uncommon
Dizziness on first doserare
Full side effects guide with management tips →

Clinical Research

Phase 2
GH secretion dose-response

Ipamorelin reliably stimulates GH secretion in a dose-dependent manner with high selectivity, producing minimal cortisol or prolactin elevations compared to GHRP-6 or GHRP-2.

Source: Raun et al., European J Endocrinology 1998
Phase 2 (postoperative ileus)
Gut motility restoration after bowel surgery

Ipamorelin accelerated return of gut motility compared to placebo, suggesting utility beyond body composition.

Source: Greenwood-Van Meerveld et al., 2012

Best Used For

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Frequently Asked Questions

What does Ipamorelin do?

Ipamorelin stimulates the pituitary gland to release growth hormone in natural pulses. Over time, elevated GH levels support fat loss, lean muscle preservation, improved recovery, deeper sleep, and various anti-aging effects.

Is Ipamorelin better than HGH injections?

Ipamorelin stimulates your body's own GH production rather than replacing it externally. This is considered safer by many practitioners since it maintains the natural pulsatile GH pattern and does not suppress endogenous production the way exogenous HGH can.

What is the Ipamorelin + CJC-1295 stack?

This is a popular combination: Ipamorelin (GHRP) + CJC-1295 (GHRH analog) work synergistically. The GHRH amplifies the magnitude of the GH pulse while ipamorelin triggers the pulse. Many peptide protocols combine both for enhanced GH secretion.

How long should you take Ipamorelin?

Common protocols run 3–6 months continuously. Some practitioners cycle it (e.g., 3 months on, 1 month off) to prevent receptor desensitization, though evidence for this practice in humans is limited.

What is the correct Ipamorelin dosage?

Research protocols typically use 200–300 mcg per injection, 1–3 times daily. Best taken on an empty stomach, with one dose before bed to coincide with natural GH pulsing during sleep. There is no FDA-approved dose — these ranges come from animal studies and clinical practice reports.

Does Ipamorelin help with fat loss?

Indirectly, yes. Growth hormone stimulates lipolysis (fat breakdown), particularly from visceral fat depots. Over a multi-month protocol with concurrent resistance training, some users see modest improvements in body composition — reduced fat, maintained or slightly increased lean mass. Ipamorelin is not a direct fat-loss drug.

Does Ipamorelin increase cortisol or prolactin?

Unlike older GHRPs (GHRP-6, GHRP-2), Ipamorelin does not significantly raise cortisol or prolactin. This selectivity is one of its key advantages — other secretagogues that raise cortisol can partially negate the anabolic benefits of GH release. Ipamorelin's clean GH pulse is why many practitioners prefer it.

Is Ipamorelin FDA approved?

No. Ipamorelin is not FDA approved for any indication. It is classified as a research chemical. It was studied pharmaceutically (Ferring Pharmaceuticals developed it), but it never advanced to an approved drug product. It remains available from research suppliers as a research chemical.

What are the side effects of Ipamorelin?

Reported side effects are generally mild: transient water retention (common), headache shortly after injection (common, resolves within 30 minutes), tingling or numbness (less common), and fatigue if dosed too high. At high doses, elevated GH can temporarily worsen insulin sensitivity. Serious adverse effects have not been documented in human use reports, though formal safety trials do not exist.

Can Ipamorelin be used for anti-aging?

GH levels naturally decline with age (somatopause), contributing to reduced lean mass, increased body fat, impaired recovery, and reduced energy. Ipamorelin attempts to partially restore youthful GH patterns without the risks of exogenous HGH. Whether this translates to meaningful anti-aging effects in healthy adults is not established by controlled trials. It is used in some longevity medicine practices for this purpose.

Where to Source Ipamorelin

Sourcing guidance, supplier vetting criteria, and price benchmarks.

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