Hexarelin vs Ipamorelin vs GHRP-2: GH Secretagogue Showdown

How GH Secretagogues Work

All three of these peptides work by binding to the ghrelin receptor (GHSR-1a) on the pituitary gland. When they bind, the pituitary releases growth hormone into the bloodstream. It’s a simple signal — but the strength and specificity of that signal varies significantly between these three compounds.

They’re often paired with a GHRH (growth hormone releasing hormone) like CJC-1295 to create a “pulse” of GH that mimics natural physiological release more closely than either compound alone.

Potency: How Much GH Do They Release?

In head-to-head research studies, the GH release hierarchy is generally:

Hexarelin > GHRP-2 > Ipamorelin

Hexarelin produces the largest GH pulse of the three at equivalent doses. GHRP-2 comes in second. Ipamorelin produces a smaller but cleaner pulse.

More GH isn’t always better in research — it depends on what you’re studying and what side effects matter for your protocol.

Selectivity: What Else Do They Stimulate?

This is where the three diverge most meaningfully.

Hexarelin: Least selective. It releases GH strongly, but also significantly raises cortisol and prolactin. It also binds to CD36 receptors and shows cardioprotective effects unrelated to GH — an interesting side effect that’s become its own research area.

GHRP-2: Moderately selective. It produces a strong GH pulse with moderate cortisol and prolactin increases. Also known to strongly stimulate appetite via ghrelin pathways.

Ipamorelin: Most selective. It produces a GH pulse with minimal cortisol, prolactin, or appetite stimulation. The cleanest GHRP for GH-specific research where you don’t want confounding variables.

View Hexarelin →
View GHRP-2 →

Desensitization: How Quickly Does the Response Drop?

Desensitization occurs when continuous stimulation causes the pituitary to become less responsive over time.

Hexarelin desensitizes the fastest — continuous daily use shows significant GH pulse attenuation within weeks in some studies. Researchers typically cycle it to maintain response.

GHRP-2 desensitizes more slowly. Ipamorelin shows the least desensitization, making it more suitable for longer continuous protocols in research settings.

Hexarelin’s Unique Cardioprotective Research

Hexarelin has attracted separate research interest for its cardioprotective properties — independent of GH release. It appears to act on CD36 receptors in heart tissue, reducing ischemia-reperfusion injury and protecting cardiac function in animal models.

This makes Hexarelin relevant to two separate research areas: GH axis studies and cardiovascular protection studies.

Head-to-Head Comparison Table

Which to Choose for Research?

• Maximum GH release study: Hexarelin or GHRP-2
• GH-specific study without cortisol/prolactin confounders: Ipamorelin
• Long-duration GH protocol without desensitization: Ipamorelin
• Appetite/ghrelin signaling research: GHRP-2
• Cardiac protection research: Hexarelin

Summary of Key Research References

Written by the NorthPeptide Research Team