Growth hormone
GHRP-2
A growth-hormone secretagogue with direct human evidence for increased appetite, distinct from evidence of muscle gain.
Experimental / study-specific evidence
Also known as: pralmorelin
Practical use
Applying the explained evidence
- Where it fits
- A growth-hormone secretagogue with direct human evidence for increased appetite, distinct from evidence of muscle gain.
- Put the information into practice
- An acute hormone response, a larger meal and a sustained change in body composition are different outcomes. Only the first two were directly established in these experiments.
- Outcome versus a marker
- Separate a change in a hormone measurement or body-composition estimate from the outcome you actually care about. Look for direct measurement of function, symptoms and adverse events.
- Keep this limit in view
- A seven-person acute study cannot establish sustained weight or muscle gain. The reported uncertainty is a standard error, not an interval containing most individual responses.
Overview
GHRP-2 stimulates the ghrelin-receptor pathway. Human experiments show effects on both growth-hormone secretion and eating behavior, rather than an isolated increase in a single hormone.
Risks and limitations
Increased appetite is a demonstrated effect and can be undesirable depending on the clinical goal. The short experiments below cannot estimate long-term metabolic, cardiovascular or cancer outcomes.
How to read this
An acute hormone response, a larger meal and a sustained change in body composition are different outcomes. Only the first two were directly established in these experiments.
Research explained
Acute eating experiment in lean men
Who was studied
Seven healthy lean men received GHRP-2 or saline during 270-minute study sessions.
What was found
Energy intake at a buffet meal increased by an average 35.9% ±10.9% with GHRP-2 versus saline. Growth-hormone exposure also increased. Meal macronutrient proportions did not differ.
What it cannot establish
A seven-person acute study cannot establish sustained weight or muscle gain. The reported uncertainty is a standard error, not an interval containing most individual responses.
Read the original studyFollow-up experiment across body sizes
Who was studied
19 weight-stable participants: ten lean and nine with obesity; randomized double-blind three-visit comparison.
What was found
Food intake rose 10.2% ±3.9% and 33.5% ±5.8% under the lower and higher active research conditions versus placebo. Obesity did not eliminate the response.
What it cannot establish
These are meal-level results under controlled infusions. They are not a long-term weight-management study or a home-use regimen.
Read the original studyWhy appetite belongs in the mechanism discussion
The ghrelin-related pathway influences more than pituitary growth-hormone release. A compound marketed only by its effect on GH may omit a practically important appetite effect. The small human feeding studies make that distinction measurable.
Supporting sourceSources
Acute eating experiment in lean men
Follow-up experiment across body sizes
Sources checked 2026-09-28.
General education; not a personal treatment plan.