Growth hormone axis

Hexarelin

Also called Examorelin, EP-23905

Hexarelin is a synthetic growth hormone-releasing peptide closely related to GHRP-6. It has been used in research to test how well the pituitary releases growth hormone. It is not an approved medicine and is banned in sport.

Early human dataSome small human studies exist; evidence is limited.

All printable flashcards

Illustrative chain. The exact sequence has not been published in a source we could verify.

Overview

How it works

Established for the class: activates the ghrelin receptor (GHS-R1a) to release growth hormone. Some research also describes binding to the cardiac receptor CD36 (proposed).

What research shows

Doses studied in people

Human diagnostic and research studies of hexarelin exist, but their doses were not verified from a primary source for this profile.

Read this first: these are the amounts given to participants in published studies or written on official prescribing labels, reported for reference. They are not recommendations. Trial doses were chosen for specific patients under medical supervision, and a dose that is safe in one person can be harmful in another.

Weekly protocol

How the schedule looks week by week. Each chart says where it comes from: a prescribing label, a clinical trial, or a protocol commonly reported online.

Long-term hexarelin study (Rahim 1998)

Clinical trial

One week

D1D2D3D4D5D6D7

Twice daily · Subcutaneous injection

Dose by week

1.5 mcg/kgwk 1–16

Course: 16 weeks
Note: Small study of the GH response during long-term use; the GH response faded during treatment and recovered after stopping.
Source: Rahim A, O'Neill PA, Shalet SM. Growth hormone status during long-term hexarelin therapy. J Clin Endocrinol Metab 1998;83(5):1644

Commonly reported protocol

Commonly reported, not studied

One week

D1D2D3D4D5D6D7

Two to three times daily, on an empty stomach · Subcutaneous injection

Syringe units (U-100)

Vial Water added

Dose by week

100–200 mcg per injectionwk 1–12

Supplies for one course (estimate)

Counts only. This site does not sell or link to supplies.

Course: 8–12 weeks on, then 4 weeks off
Note: Desensitization is reported within 1–2 weeks of continuous use, which is why cycling is advised.
Source: Peptide Protocol Wiki: Hexarelin dosing protocols

Reference only, not a recommendation. Charts marked "commonly reported" describe what public sources say people use. They have not been tested in trials, and their safety and effect are unknown. Label and trial schedules were set for specific patients under medical supervision. Use the calculator only to understand the arithmetic.

Vial math

Many research vials hold 5 or 10 mg of powder. This table shows how much ends up in each mark on a U-100 insulin syringe for common amounts of added liquid. It is arithmetic only, not a dose.

Vial	Liquid added	Concentration	Per unit (0.01 mL)
5 mg	1 mL	5 mg/mL	50 mcg	Open in calculator
5 mg	2 mL	2.5 mg/mL	25 mcg	Open in calculator
5 mg	3 mL	1.67 mg/mL	16.7 mcg	Open in calculator
10 mg	1 mL	10 mg/mL	100 mcg	Open in calculator
10 mg	2 mL	5 mg/mL	50 mcg	Open in calculator
10 mg	3 mL	3.33 mg/mL	33.3 mcg	Open in calculator

More sizes: all vial sizes · How this works: Syringes and units · Reconstitution guide.

Safety

Unknown long-term safety; no FDA safety review published.

Report side effects of any drug or product to the FDA through MedWatch. For a possible poisoning in the US, call Poison Control at 1-800-222-1222.

Legal status

FDA: Not FDA-approved
Compounding: Not on FDA's 503A (May 2026) or 503B (March 2025) nomination/category lists; not a component of an approved drug, so not eligible for compounding
Sports (WADA): Prohibited at all times (S2.2.4 GHRPs; examorelin/hexarelin named)

Rules change often. See Legal status of peptides for how these categories work.

History

Developed in the early 1990s as a more potent GHRP-6 analogue. It does not appear on FDA's 503A or 503B bulk-substance nomination lists.

Common questions

Is hexarelin FDA-approved or legal to compound?

It is not FDA-approved and does not appear on FDA's 503A or 503B compounding lists, so it is not eligible for compounding ²³.

What doses were studied?

Human diagnostic and research studies exist, but their doses could not be verified from a primary source for this profile.

Is hexarelin safe?

Long-term safety is unknown, and FDA has not published a safety review of it.

Is hexarelin banned in sport?

Yes. WADA prohibits it at all times and names it (as examorelin/hexarelin) in its growth hormone releasing peptide class ¹.

Related compounds

Growth hormone axisEarly human dataFlashcard

GHRP-6

Growth hormone releasing peptide-6 · SKF-110679

GHRP-6 is one of the first synthetic peptides found to release growth hormone through what was later named the ghrelin receptor.

Growth hormone axisEarly human dataFlashcard

GHRP-2

Pralmorelin · KP-102

GHRP-2 is a small synthetic peptide that strongly triggers growth hormone release by acting on the ghrelin receptor.

Growth hormone axisEarly human dataFlashcard

Ipamorelin

Ipamorelin acetate · NNC 26-0161

Ipamorelin is a small lab-made peptide (five building blocks) that copies the hunger hormone ghrelin to make the pituitary release growth hormone.

Sources

Last reviewed 2026-10-25 · How we research · Found an error? See our corrections policy.