Hexarelin and ipamorelin are often compared because they belong to the same family of research compounds. Both are growth hormone secretagogues, and both act on the same receptor. The interesting part is where they differ, which comes down to selectivity. Here is the plain version.
What hexarelin is
Hexarelin is a synthetic growth hormone secretagogue. According to PubMed, it acts on the growth hormone secretagogue receptor, the same receptor targeted by ghrelin, and research has examined how it influences that receptor at the pituitary and hypothalamus (Bresciani et al., 2004, DOI). It belongs to the older GHRP class of secretagogues.
What ipamorelin is
Ipamorelin is a synthetic pentapeptide that acts on the same ghrelin, or GHRP, receptor. According to PubMed, it was described as the first selective growth hormone secretagogue. In that early research it released growth hormone with potency similar to the older GHRP compounds, but without the rise in ACTH and cortisol that the older GHRP class produced (Raun et al., 1998, DOI).
The difference that actually matters
Both compounds act on the same receptor, so the difference is not the pathway. It is selectivity. The older GHRP class, which includes hexarelin, was associated in research with effects on additional hormones beyond growth hormone. Ipamorelin was singled out as more selective for growth hormone release in those same studies. That selectivity is the distinction researchers point to when they compare the two.
Why the comparison comes up
Because they share a receptor and a research category, hexarelin and ipamorelin are natural points of comparison, and researchers often weigh one against the other when designing a study. As always, the right choice depends on the research question, not on one being better than the other.
Sourcing hexarelin and ipamorelin
For either compound, documentation is the thing that matters. Look for a per batch Certificate of Analysis you can see before you buy, HPLC purity on the specific lot, mass spectrometry confirmation, and a lot number tied to your vial.
Peptide Hackers carries both hexarelin and ipamorelin with that documentation on every batch. For researchers in the Los Angeles and Orange County areas, you can order online and pick up the same day in person, with shipping available if you prefer delivery. The full catalog is at peptidehackers.com.
All products are for laboratory research only. Not for human or veterinary use.
Research Use Only
This article is provided for educational purposes. All peptides discussed are sold for research use only and are not intended for human consumption or therapeutic use.