The Clean Pulse

Ipamorelin

Also known as GHRP (ghrelin mimetic)

Summary coverage

At a glance

What it is: Described in our sources as the most selective GH secretagogue: no cortisol, prolactin or appetite spike.

Evidence: Small human studiesHow the tiers workPhase 2 studies confirmed selective GH release without cortisol or prolactin increases, and it has been studied for post-operative ileus recovery, but there are no large trials of the stacks it is normally used in. Why this tier

Half-life: About 2 hours, when given into a vein; From Gobburu et al., Pharmaceutical Research, 1999
Routes: Subcutaneous
Category: Growth hormone
FDA: FDA Category 2; As of 3 August 2026. What that means
WADA: Prohibited (S2.2.4)

Putting Ipamorelin on a schedule, with the vial it comes from and a log of each dose, happens in the app: Claritide for iPhone.

Evidence

Why this tier

Phase 2 studies confirmed selective GH release without cortisol or prolactin increases, and it has been studied for post-operative ileus recovery, but there are no large trials of the stacks it is normally used in.

Overview

What it is

Ipamorelin is a growth hormone-releasing peptide that works as a ghrelin receptor agonist, stimulating GH release through a completely different pathway than GHRH analogs. It is described in our sources as the cleanest GH secretagogue available: it triggers GH release without raising cortisol or prolactin and without stimulating appetite, unlike older GHRPs such as GHRP-6.

Mechanism

How it works

Ipamorelin activates the ghrelin receptor (GHS-R) on the pituitary. Ghrelin is the hunger hormone, and its receptor also sits on the GH release pathway, which is why this class works at all. The functional effect is suppression of somatostatin, the hormone that normally brakes GH release. Pairing it with a GHRH analog produces a larger pulse than either alone, because one compound is signalling for release while the other removes the restraint. Ipamorelin's distinguishing feature is selectivity: it hits the GH pathway without the cortisol, prolactin and appetite effects that older ghrelin mimetics produce.

Dosing

Commonly researched ranges

These are figures reported in published literature and practitioner protocols: a commonly researched range, not a recommendation. Claritide does not tell you what to take.

With a GHRH analog100–300 mcg
Once daily · Bedtime, empty stomach, the same injection window as tesamorelin
Our tesamorelin page gives 100–300 mcg at bedtime; our comparison page gives 100–200 mcg per injection, 1–3 times daily.
Fat-loss stack protocol200–300 mcg
2–3 times daily · Commonly morning and before bed, empty stomach 2+ hours after a meal
The schedule our weight-loss guide describes alongside tesamorelin.

Phase	Amount	Frequency	Timing	Note
With a GHRH analog	100–300 mcg	Once daily	Bedtime, empty stomach, the same injection window as tesamorelin	Our tesamorelin page gives 100–300 mcg at bedtime; our comparison page gives 100–200 mcg per injection, 1–3 times daily.
Fat-loss stack protocol	200–300 mcg	2–3 times daily	Commonly morning and before bed, empty stomach 2+ hours after a meal	The schedule our weight-loss guide describes alongside tesamorelin.

Cycle guidance: 8–12 weeks on, 4 weeks off alongside tesamorelin or CJC-1295.
Goals: Muscle, Sleep, Recovery, Fat loss

Legal standing

Where this sits with the FDA

Dated, sourced, and separate from whether it works. Removal from a warning list is not permission to compound.

FDA Category 2as of 3 August 2026 · US

503B Category 2 · bulk substances that may present significant safety risks; the separate 503A nomination was withdrawn

Both facts matter and most write-ups carry only one. Ipamorelin holds a live FDA “significant safety risk” designation for 503B outsourcing facilities, and its 503A nomination was withdrawn. Neither route makes it lawfully compoundable.

Last change · 22 April 2026 · The 503A nomination was withdrawn. The 503B Category 2 designation was not affected and is still live.

Primary source

Sport

WADA status

The 2026 Prohibited List entered force on 1 January 2026.

Prohibited (S2.2.4)

Named on the 2026 List under S2.2.4, growth hormone secretagogues and GHRPs. Prohibited at all times.

Reconstitution

Mixing recipes our sources document

Concentration (mg/mL) = vial mg ÷ diluent mL. On a U-100 barrel, 1 unit = 0.01 mL.

Not established in available literature. Use the calculator with the figures printed on your own vial.
Open the calculator

Expectations

Week by week

What our material describes people reporting. Individual responses vary widely.

1
Early weeks
Improved sleep and recovery are the first effects our sources describe, driven by amplified GH pulses during deep sleep.
2
Week 4–8
Our tesamorelin page describes stack users reporting significant fat reduction beginning in this window.

Tolerability

Side effects

Grouped by how often our sources report them. Percentages appear only where a published trial figure exists.

Uncommon

HeadacheMild, typically early in use.
Flushing or warmth
Injection site irritationMild.
Water retentionMild, usually transient.

Safety

Contraindications and interactions

Do not use if

Active cancer: GH promotes cell proliferation
Stacking with other GH secretagogues or exogenous GH without medical guidance
Pregnancy or nursing: no safety data in our sources

Interactions

Other GH secretagogues and exogenous GHcaution
Cumulative GH-axis load. Tesamorelin plus ipamorelin is the one pairing our sources describe as intentional and mechanistically complementary, but it is still two GH-axis compounds.
Cancer therapiesavoid
Growth-promoting pathways.

Absence from this list does NOT mean safety. It means lack of research.

Handling

Storage and cost

Storage: Lyophilized powder: refrigerator 2–8°C, freezer −20°C for long-term storage. Reconstituted with bacteriostatic water: refrigerate and discard after 28 days.
Cost: Not established in available literature

Combinations

Stacks with

Only pairings our own material actually documents. Stacking is the least evidence-based part of this field.

TesamorelinThe GH Optimizer CJC-1295 (no DAC)The Short Pulse

Curated stacks including it

Deep dive

Ipamorelin in full

Limited coverage

Ipamorelin appears throughout our material as the second half of a stack rather than as a standalone guide. This record reflects only what our sources state.

What it is

A growth hormone-releasing peptide and ghrelin receptor agonist. It stimulates GH release through the GHS-R receptor, a completely separate pathway from the GHRH receptor that tesamorelin and CJC-1295 use.

The selectivity that defines it

Older ghrelin mimetics have a problem: hitting the ghrelin receptor tends to drag other things along with it. GHRP-6 produces a strong GH release but also spikes cortisol and prolactin and stimulates appetite. GHRP-2 is more selective but still less clean.

Ipamorelin is described in our sources as the cleanest GH secretagogue available: selective GH release with no cortisol increase, no prolactin increase, and no appetite stimulation. Phase 2 studies confirmed this profile. That is the entire reason it displaced the older GHRPs in practice.

Why it pairs with a GHRH analog

Tesamorelin or CJC-1295 signals the pituitary to release growth hormone. Ipamorelin suppresses somatostatin, the hormone that brakes that release. Our tesamorelin page puts it plainly: one pushes the gas, the other releases the brake, and the combined pulse is significantly greater than either alone. Pre-blended tesamorelin/ipamorelin vials at 10 mg / 3 mg exist for exactly this reason.

What our sources give as dosing

100–300 mcg subcutaneously at bedtime alongside tesamorelin, on an empty stomach. Our comparison page gives 100–200 mcg per injection, one to three times daily. Our weight-loss guide describes 200–300 mcg two to three times daily in the tesamorelin stack. Cycles of 8–12 weeks on, 4 weeks off.

The cautions our sources raise

Active cancer is a contraindication for any GH-axis compound. The Playbook's stacking warning applies: combining GH-releasing peptides can cause unpredictable spikes in cortisol, prolactin or blood glucose depending on the compounds involved, and the tesamorelin/ipamorelin pairing, however well-reasoned, is still two GH-axis compounds running at once. IGF-1 monitoring is the standard recommendation.

References

Sources

1
Raun et al., 1998 · Ipamorelin, the first selective growth hormone secretagogue, Eur J Endocrinol 139(5)

Every record in this library is free to read, and it stays free. Your own schedule, vials and log live in the app: Claritide for iPhone.