Comparison
The two older GHRP-class secretagogues, compared on strength, hunger, and what each one's evidence actually shows.
Both raise growth hormone in human challenge studies and both raise ACTH and cortisol alongside it. The practical differences are potency per microgram, hunger stimulation, and GHRP-2's Japanese diagnostic approval as pralmorelin.
GHRP-2 is generally described as the stronger secretagogue per microgram, with less hunger stimulation than GHRP-6. Both are less selective than ipamorelin: comparative endocrine work found both raise ACTH and cortisol at GH-effective doses.
GHRP-6's hunger effect is direct ghrelin-receptor pharmacology, not a side quirk: the same receptor drives appetite signaling. That makes GHRP-6 the one discussed for eating support and the worse choice when appetite stimulation is unwanted.
GHRP-2 is approved in Japan as a diagnostic agent (pralmorelin) for growth-hormone secretion testing: a real but narrow standing that says nothing about physique use. GHRP-6 has no such approval anywhere, and both are WADA-prohibited.
| Dimension | GHRP-2 | GHRP-6 |
|---|---|---|
| Overall evidence grade | C | D |
| Evidence label | Limited human evidence | Limited human evidence |
| Regulatory status | Varies by product and jurisdiction | Not FDA-approved for listed uses |
| Editorial confidence | Moderate confidence | Low confidence |
| Efficacy | 0/5 not mapped | 0/5 not mapped |
| Safety | 0/5 not mapped | 0/5 not mapped |
| Regulatory risk | 3/5 moderate | 3/5 moderate |
| Product quality risk | 3/5 moderate | 3/5 moderate |
| Primary claim categories | Growth hormone and secretagogues, Muscle growth and performance | Growth hormone and secretagogues, Muscle growth and performance |
WADA. The 2026 Prohibited List 2026.
Accessed 2026-06-08.
WADA states that S0 non-approved substances are prohibited at all times when they have no current approval by a governmental regulatory health authority for human therapeutic use.
FDA. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks 2026.
Accessed 2026-06-08.
FDA summarizes potential significant safety risks and missing safety information for several nominated peptide bulk substances.