Growth Hormone Secretagogue

Ipamorelin

Selective GH secretagogue with a cleaner side-effect profile than GHRP-6.

GHS-R1a signalingGH/IGF-1 axisGhrelin receptor modulationGHRH synergy pathways

52 C+

Evidence Score

ⓘ For informational purposes only — not medical advice.

Score Breakdown

Overview

Ipamorelin is a synthetic pentapeptide growth hormone secretagogue that selectively stimulates growth hormone (GH) release without significantly affecting cortisol, prolactin, or ACTH levels. It has undergone Phase II clinical trials for post-operative ileus but is primarily used off-label in anti-aging and performance contexts.

Mechanism of Action

Ipamorelin binds the growth hormone secretagogue receptor (GHS-R1a, the ghrelin receptor) in the pituitary, triggering pulsatile GH release. Its selectivity for GH over other pituitary hormones distinguishes it from earlier secretagogues like GHRP-6. GH then stimulates hepatic IGF-1 production, driving downstream anabolic effects.

Evidence Base

Phase II clinical trials were conducted for post-operative ileus recovery (Helsinn Healthcare). These trials demonstrated GH elevation and safety data in hospitalized patients. No FDA approval was obtained. Additional published pharmacokinetic studies exist. Off-label use in anti-aging clinics is widespread.

Gene Pathway Detail

GHS-R1a activation stimulates the GH/IGF-1 axis, driving hepatic IGF-1 gene expression and downstream anabolic gene programs including IGFBP-3, ALS, and tissue-specific IGF-1 receptor signaling. Biomeme could monitor IGF-1 axis gene expression to confirm GH secretagogue activity.

mRNA Monitoring Insight

IGF-1 and IGFBP gene expression changes are monitorable and provide functional readout of GH axis activation. This is valuable because serum GH levels are pulsatile and difficult to interpret from single blood draws, while mRNA changes reflect sustained pathway engagement.

Safety Considerations

Phase II trial data showed acceptable safety profile. Fewer off-target effects than earlier GH secretagogues (no significant cortisol/prolactin increase). Long-term safety data is limited. Theoretical concerns around sustained GH elevation include insulin resistance and potential tumor promotion.

FAQ

How is ipamorelin different from HGH?

Ipamorelin stimulates your body to release its own growth hormone in natural pulses, rather than injecting synthetic GH directly. This preserves the natural pulsatile pattern and feedback regulation.

Quick Facts

Category: Growth Hormone Secretagogue
Score: 52/100 (C+)
Gene Pathways: 4 characterized

Sources

[1] Ipamorelin Phase II — J Clin Endocrinol Metab 2006

Compare Others

Monitor Your Peptide Response.

Biomeme's transcriptomic platform tracks molecular pathway engagement so you know if your therapy is working.