GHRH analogs vs ghrelin mimetics

Which peptides use the GHRH pathway?

Sermorelin, Tesamorelin, CJC-1295 (no DAC) and CJC-1295 + DAC all carry the same recorded mechanism, and each of those 4 cells is traced to a document. What the phrase means is at its plainest in the oldest of them, which describes sermorelin by giving its sequence rather than its category.

An analog of the hormone, then — the first twenty-nine amino acids of a forty-four-amino-acid hypothalamic peptide, arriving at the receptor the body’s own GHRH arrives at. The other three in this group are recorded under the same class for the same reason. What separates them is not the door they knock on; it is how long they last once they are through it, which is the next section but one.

There are two classes in this column and no third, which is what makes it a line rather than a spectrum. A class is also not a license, a safety finding or a dose: it is one row of the matrix, and the other 4 disagree with it constantly.

How ipamorelin differs

Ipamorelin is the exception, and the paper that introduced it did not leave the question open. Its authors ran the compound against antagonists of both receptor systems and reported which one answered.

The later paper this site cites for the cell says the same thing in the vocabulary the cell uses, describing ipamorelin as “ipamorelin, a selective growth hormone secretagogue and agonist of the ghrelin receptor”. Ghrelin is a stomach hormone; the receptor it acts on is not the GHRH receptor, and a molecule that reaches growth hormone through it is doing a different thing on the way, whatever the shelf it is sold from says.

That is the whole of the difference this page is about, and it is also the reason the two are so often sold together rather than instead of each other. What the literature records about combining them is on sermorelin vs ipamorelin, which takes one such pair in detail; what the sellers do with it is below.

What combination products pair together

Here is what makes the split worth a page rather than a footnote. 6 of the 51 priced listings this site has read name more than one of these 5 molecules, across 2 of the 22 sellers on the roster — and 6 of those 6 put one molecule from each side of the split into the same product. Not one of them pairs two molecules from the same class.

These combinations contain ingredients that act through different receptors. That explains the proposed pairing, but does not prove that combining them improves outcomes or establishes a suitable dose.

What mechanism cannot tell you

The class is a weak predictor of the thing a buyer plans around. Inside the group of 4, the measured half-lives run from 8 min for Tesamorelin to 5.8–8.1 days for CJC-1295 + DAC — a factor of somewhere between 1044 and 1458, between two molecules the mechanism row files together. One is injected daily and the other weekly, and the row that groups them says nothing about either schedule.

A fourth member of the class cannot be put on that scale at all. CJC-1295 (no DAC) is recorded as not reported in humans, which is what the review covering that exact compound reports. Same class, same backbone, and no answer to how long it lasts.

The other rows disagree with the class too. The regulatory record splits this same group of 4 into 3 on its own, and which of these is FDA approved? takes that column the way this page takes the mechanism one. Nothing on this page says a molecule in either class is safer, stronger or better suited to anybody — that is a clinician’s judgment about a person, and this is a row in a table.

Sources

The references below support the mechanism comparison. Quotations are taken from the published abstracts, rather than a review of the full papers.