Head to head

GHRP-2 vs Hexarelin

GH secretagogue

Side-by-side on muscle growth, dosing, kinetics and evidence — with an honest verdict at the end.

Verdict

No winner in this data

The evidence tiers match and the goal overlap is real, so nothing here supports calling one better. What separates them is practical: once daily on 12 weeks for GHRP-2 against once daily on 4 weeks for Hexarelin. Pick the one you will actually run correctly.

What you are actually choosing between

Both are classed here as growth hormone secretagogues, so this is a within-class choice: the mechanism is broadly shared and what separates them is kinetics, route, and how much has actually been tested.

The overlap is muscle growth and recovery and sleep. On this site's goal weighting — an editorial priority score, not a measure of effect size — GHRP-2 rates 3/5 for muscle growth and Hexarelin rates 4/5. Outside that overlap only GHRP-2 goes further, carrying weight for appetite control; Hexarelin's declared goals stop at the overlap.

The evidence

GHRP-2 sits one step firmer: approval from a regulator somewhere, though not a current FDA or EMA label — registered in Japan as pralmorelin for a single-dose diagnostic test, not chronic use. Hexarelin has controlled human trials behind it, without an approval — human GH-response data is real, but the response blunts within weeks. One tier is a real difference but not a decisive one; it should not on its own settle the choice.

How they differ in practice

Half-lives are close — 1 h for GHRP-2, 1 h for Hexarelin — and both are dosed once daily, so the rhythm of actually running them is the same.

Committed time differs: GHRP-2 runs 12 weeks, Hexarelin runs 4 weeks.

Risk and difficulty

GHRP-2 is rated intermediate here and Hexarelin advanced. That rating is about how much can go wrong in handling, dosing and monitoring, not about how well either works.

Source notes

What the evidence actually says

Verbatim, so you can check the verdict above against what it was built from.

GHRP-2

Synthetic hexapeptide ghrelin receptor (GHS-R1a) agonist. Unusually for this corner of the market it has real human data: it has been studied as a growth hormone secretagogue in published dose-response work, and the same molecule is registered in Japan as pralmorelin for use as a single-dose diagnostic test of growth hormone deficiency. That diagnostic use is a one-off intravenous challenge, not a chronic subcutaneous protocol, so the human evidence supports the fact that it releases growth hormone rather than the community habit of dosing it daily for months. It is not approved for physique or anti-ageing use anywhere. It is less selective than ipamorelin: expect measurable prolactin and cortisol elevation, which is the usual reason people switch away from it. The 100-300 mcg per dose range, often split into two or three doses a day, comes from practice rather than from a label.

Hexarelin

Synthetic hexapeptide ghrelin receptor (GHS-R1a) agonist and one of the most potent GH secretagogues studied in humans, with additional cardiac data. Its defining practical problem is tachyphylaxis: repeated dosing blunts the GH response over roughly two to four weeks, which is why it is cycled short rather than run continuously. It also lacks the selectivity of ipamorelin, so prolactin and cortisol elevation are expected at higher doses.

Side by side

The numbers

GHRP-2 compared with Hexarelin
Attribute	GHRP-2	Hexarelin
Class	GH secretagogue	GH secretagogue
Routes	Subcutaneous, Intramuscular	Subcutaneous, Intramuscular
Dose range	100 mcg–300 mcg (typical 200 mcg)	50 mcg–200 mcg (typical 100 mcg)
Frequency	Once daily	Once daily
Half-life	1 h	1 h
Cycle length	12 weeks	4 weeks
Experience	Intermediate	Advanced
Evidence	Approved elsewhere	Controlled human trials
Contraindications	Pregnant / nursing Active malignancy Under 18	Pregnant / nursing Active malignancy Under 18
Side effects	Raises prolactin and cortisol more than ipamorelin does — this is its main practical drawback, and it scales with dose, so pushing past roughly 300 mcg per injection buys little extra growth hormone while making the hormonal spillover worse Hunger spike within about half an hour of dosing, which works against a cut Water retention, morning puffiness, and numb or tingling hands Head rush, flushing or brief light-headedness just after injection Blunted response over months of uninterrupted daily use, so it is usually cycled Injection site redness or itching	Marked receptor desensitisation — the GH response falls off within a few weeks of continuous daily use, so cycles are kept short with washout periods Raises prolactin and cortisol more than ipamorelin does Strong hunger spike within 20 to 30 minutes of dosing Water retention, puffiness and numb or tingling hands Head rush, flushing or transient light-headedness after injection Injection site irritation

Turn a typical dose into a mark on the syringe: GHRP-2Hexarelin

Goals

Where they overlap, and where they do not

Goal	GHRP-2	Hexarelin
muscle growth	GHRP-2: 3/5	Hexarelin: 4/5
recovery and sleep	GHRP-2: 3/5	Hexarelin: 3/5
injury repair	GHRP-2: 2/5	Hexarelin: 3/5
fat loss	GHRP-2: 2/5	Hexarelin: 2/5
longevity	GHRP-2: 1/5	Hexarelin: 1/5
appetite controlone only	GHRP-2: 3/5	Hexarelin: —

They overlap on 5 goals and diverge on 1. Weights are this site’s editorial priority score out of 5 — how central a goal is to why people use a compound. They are not effect sizes and two 5s do not mean two equal results.

Go deeper

MonographGHRP-2Mechanism, protocol, storage, sources.MonographHexarelinMechanism, protocol, storage, sources.ToolReconstitution calculatorTurn either dose above into a mark on the syringe.

Other comparisons with these two

Educational information only, not medical advice. Talk to a licensed clinician before starting, changing, or stopping anything.