Sermorelin vs other GH secretagogues
“Growth hormone secretagogue” is a commercial label covering at least two mechanistically unrelated classes. This page separates them — and explains which compounds in the category we have chosen not to stock, and why.
Two different receptors
Compounds marketed under the secretagogue heading generally fall into one of two groups:
- GHRH analogues — structural analogues of growth hormone-releasing hormone, acting at the GHRH receptor. Sermorelin is the archetype.
- Ghrelin-receptor agonists — acting at the growth hormone secretagogue receptor, a different receptor with a different endogenous ligand.
Grouping them under one commercial term does not make them mechanistically similar. They act on different receptors, through different signalling, and the research literatures are separate.
| GHRH analogues | Ghrelin-receptor agonists | |
|---|---|---|
| Receptor | GHRH receptor | Growth hormone secretagogue receptor |
| Endogenous ligand | GHRH | Ghrelin |
| Example | Sermorelin | Various; none stocked here |
| Regulatory history | Sermorelin held FDA approval as Geref | No approved product in this class for these purposes |
Why sermorelin is the one we stock
Three reasons, stated plainly:
- It has been through regulatory review. Sermorelin held FDA approval as Geref. Whatever else is true, its evidence package was examined by a regulator — which is not the case for most compounds in this category.
- It left the market for commercial reasons. Discontinuation in the United States in 2008 is documented as a commercial decision, not a safety withdrawal.
- It has real human pharmacology data. Because it went through development, the literature includes controlled human work rather than being purely preclinical.
Compounds we deliberately do not stock
Two compounds frequently discussed alongside sermorelin — ipamorelin and CJC-1295 — were formally reviewed by the FDA’s compounding advisory committee and were not recommended, with documented safety concerns raised in that review. We do not stock them, do not intend to, and are not able to supply them.
We mention them here only because researchers routinely arrive at a sermorelin page having encountered all three in the same commercial listing, and the absence of two of them from our catalogue is a deliberate decision rather than an oversight.
Our position is that a compound flagged in a regulatory safety review does not belong in a catalogue built on documentation and transparency, regardless of demand for it.
How to compare within the class properly
If you are evaluating compounds in this area for research purposes, the questions worth asking are:
- Which receptor does it act on, and is that established or proposed?
- Does human pharmacokinetic data exist, or only animal data?
- Has it been through any regulatory evidence review, and what was the outcome?
- Is there independent replication, or does the literature originate from one group?
Those four questions separate this category faster than any marketing comparison table.
Frequently asked questions
Are all GH secretagogues the same class?
No. The term covers at least two mechanistically distinct groups acting at different receptors — GHRH analogues and ghrelin-receptor agonists.
Do you sell ipamorelin or CJC-1295?
No. Both were reviewed by the FDA’s compounding advisory committee and were not recommended, with safety concerns documented. We do not stock them and will not be adding them.
Why does sermorelin have an approval history when the others do not?
Because it was developed as a pharmaceutical product and marketed as Geref. Most compounds in this commercial category were never taken through that process.