Hexarelin (Examorelin): Identity, Human Research, and FDA Status

Last evidence review: August 27, 2026

Hexarelin is a synthetic six-residue growth-hormone secretagogue. FDA’s substance record uses examorelin as the preferred name and lists hexarelin as a synonym. The defining structure includes non-natural amino-acid features and a C-terminal amide, so a generic name alone is not enough to establish material identity.

Early human studies reported acute changes in growth hormone or selected cardiovascular measurements. Those studies were small, short, and designed around physiological endpoints. They do not establish changes in body composition, performance, recovery, aging, disease outcomes, or long-term safety.

This page separates receptor, animal, and human evidence. It contains no use instructions and does not establish that any catalog material is equivalent to the material used in a cited experiment.

Identity at a glance

FDA’s UNII record states that an identifier does not imply regulatory review or approval.[1]

Is Hexarelin a ghrelin analogue?

Hexarelin and ghrelin can act through the growth-hormone secretagogue receptor, but sharing a receptor does not make two peptides structurally interchangeable. A more precise description is synthetic peptidyl growth-hormone secretagogue studied as an agonist at the growth-hormone secretagogue receptor.

The accepted examorelin structure includes 2-methyl-D-tryptophan, D-phenylalanine, and a C-terminal lysinamide. Those details, plus the salt or counterion, must be verified before connecting a material to the literature.[1]

What do receptor studies show?

A primary 1996 study characterized a G-protein-coupled receptor for structurally diverse growth-hormone secretagogues and included hexarelin in its binding and activity work.[2] Later experiments described binding sites in human pituitary and brain membranes using a labeled hexarelin derivative.[3]

These studies support a receptor-pharmacology description. They do not establish a clinical benefit.

What has been studied in animals?

Animal work has examined growth-hormone signaling and cardiovascular models. In rat experiments, selected hemodynamic or injury-model measurements changed under the study conditions.[4][5]

Animal physiology cannot establish human cardiovascular protection, treatment of heart disease, exercise performance, body-composition change, or safety.

What has been studied in people?

Acute hormone response

A double-blind placebo-controlled study in 12 adult men reported a transient, exposure-related increase in circulating growth hormone after a single challenge.[6] The study followed hormone measurements over hours. It did not study growth, muscle, fat, recovery, symptoms, disease outcomes, or long-term safety.

Repeated endocrine challenge

A controlled study compared hormone responses after repeated challenges with hexarelin, GHRH, and their combination.[7] It was designed to investigate secretory physiology, not clinical effectiveness.

Short-term cardiac measurements

Small acute studies measured ejection fraction and hemodynamic variables. One report studied seven healthy adults, seven people with severe growth-hormone deficiency, and 12 people with severe dilated cardiomyopathy. The ejection-fraction measure changed in the healthy and growth-hormone-deficient groups but not in the dilated-cardiomyopathy group.[8]

Another study compared acute measurements in 24 men undergoing bypass surgery.[9] These experiments were too small and brief to establish durable clinical benefit, hospitalization effects, or survival.

Are there registered Hexarelin trials?

An exact-intervention search of the ClinicalTrials.gov v2 API returned no “Hexarelin” study records on August 27, 2026. Older peer-reviewed human studies clearly exist, so this should be understood only as a result of the current exact-name registry search.

What is Hexarelin’s current FDA status?

FDA’s substance system recognizes examorelin/hexarelin, but the record is not an approval. Exact-name searches for both names across the brand-name, active-ingredient-name, and generic-name fields of FDA’s approved-application dataset returned no matching product on August 27, 2026.[1][10]

A 2025 FDA warning letter described a separate firm’s “Hexarelin Acetate” drug listing as misbranded because the named product did not match the active ingredient in its structured submission.[11] That action does not determine the identity of Serum Research material. It illustrates why a label name and registration entry cannot substitute for verified ingredient identity.

Important evidence limits

• Most human evidence is old, small, and based on acute physiological measurements.
• A temporary hormone measurement is not a patient-centered outcome.
• Short-term ejection-fraction or hemodynamic changes do not establish cardioprotection or treatment.
• Hexarelin/examorelin is not structurally identical to ghrelin merely because both interact with GHS-R.
• No current exact-name ClinicalTrials.gov record was returned by the search.
• No cited source validates the sequence, salt form, content, purity, stability, or activity of a Serum Research vial.

Frequently asked questions

Are Hexarelin and Examorelin the same name?

FDA’s substance record uses examorelin as the preferred name and lists hexarelin as a synonym.

What is the defining Hexarelin sequence?

The FDA record represents the peptide as His–2-methyl-D-Trp–Ala–Trp–D-Phe–Lys-NH2. The non-natural residues and terminal amide are part of the identity.

Do human studies show that Hexarelin builds muscle or reduces fat?

No. The cited human studies measured acute hormone or cardiovascular physiology. They did not establish body-composition or performance outcomes.

Is Hexarelin FDA approved?

No matching approved product was identified in the official FDA application dataset search. A UNII is not approval.

Why does free base versus acetate matter?

A salt form changes the complete material description and can affect physical and chemical properties. The exact form and counterion must be stated and supported by analytical records.

Primary and official sources

1. FDA Examorelin/Hexarelin UNII record
2. Growth-hormone-secretagogue receptor study, PMID 8838145
3. Human brain and pituitary binding study, PMID 9614363
4. Rat ischemia-reperfusion study, PMID 10465272
5. Rat post-myocardial-infarction study, PMID 10614623
6. Double-blind placebo-controlled human physiology study, PMID 7957536
7. Repeated-challenge physiology study, PMID 8762732
8. Small acute cardiac study, PMID 11322491
9. Bypass-surgery hemodynamic study, PMID 12144941
10. FDA Drugs@FDA search portal, searches for Hexarelin and Examorelin across brand, active-ingredient, and generic-name fields documented above
11. FDA 2025 warning letter discussing a mismatched Hexarelin Acetate listing