Coming back to: GHRH analogues versus ghrelin mimetics: different mechanisms, conflated discussion

GHRH analogues versus ghrelin mimetics: different mechanisms, conflated discussion Writing it up because I had to work it out twice and would rather nobody else did.

GHRH analogues versus ghrelin mimetics — I have the observation and I do not trust my interpretation of it, so I am posting the observation and holding the interpretation back.

Numbers, method and the conditions under which they were collected are below. Interpret them however they warrant.

Taking the opening post at face value and following it one step further.

Ipamorelin selectivity claims originate in preclinical characterisation and are reasonably well supported for what they claim: less effect on cortisol and prolactin than earlier GHRPs. Whether that translates to something clinically meaningful is a different question from whether the selectivity is real.

That is the version I would defend. It is not the version I started with.

CJC-1295 exists in two forms in circulation — with and without the drug affinity complex — and they have very different half-lives. Product descriptions frequently do not say which, and the difference is not cosmetic.

Research-use-only secretagogues are not approved for human use. That statement is doing real work in this subcategory, where the published evidence base is thinner than the volume of confident discussion.

I would treat the number as indicative rather than as a measurement.

The opening post put the caveat in the right place and I want to underline it.

GHRH analogues versus ghrelin mimetics are often conflated but they are different mechanisms. GHRH analogues (like CJC-1295) cause the pituitary to release growth hormone. Ghrelin mimetics (like GHRPs) act on the ghrelin receptor directly. The effect on growth hormone secretion is similar but the mechanisms are distinct.

Growth hormone secretagogues act on the ghrelin receptor or on the growth hormone releasing hormone receptor rather than supplying growth hormone, which is the distinction that matters for anyone reading the literature.

Acetate versus trifluoroacetate is worth asking about for short peptides specifically, because the counter-ion is a larger proportion of the total mass at low molecular weight.

This is the version I would want a new member to read first.

Narrowing post #5, because the general version has more than one answer.

Reframing GHRH analogues versus ghrelin mimetics slightly, because I think the disagreement is about the question rather than the answer. If the question is "does it happen", yes. If it is "how often", nobody here knows.

Sermorelin and the growth hormone releasing hormone analogues depend on a functioning pituitary response, which is the mechanistic reason they behave differently in different people rather than a dosing problem.

Practical experience of GHRH analogues versus ghrelin mimetics, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable.

Taking GHRH analogues versus ghrelin mimetics seriously for a moment rather than deflecting: the honest position is that the community has observations and no controlled comparison, and those two things support very different sentences.

On analysis: these are short peptides and generally straightforward chromatographically, which means a poor purity result is more likely to reflect the synthesis than the method.

Building on post #10 rather than restating it.

A mass result for a short peptide is more discriminating than for a long one, because a single residue difference is a larger proportion of the total. That makes identity confirmation genuinely useful here.

I would want to see it done twice before believing it once.

CJC-1295 exists in two forms in circulation — with and without the drug affinity complex — and they have very different half-lives. Product descriptions frequently do not say which, and the difference is not cosmetic.

A partial answer, offered because a partial answer beats none.