Secretagogues and glucose tolerance: the mechanistic concern posts 31–60
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Why this subcategory is stricter about sourcing than most: the evidence base is weaker and that is precisely why documentation quality matters more. A supplier page that clearly identifies the compound and the purity is more valuable for secretagogues than for incretin agonists where the evidence base is stronger.
Worth separating two things that post #29 runs together.
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.
This is the sort of thing that ought to be settled and apparently is not.
This follows post #33 rather than contradicting it.
A definition problem is doing most of the work in this secretagogues and glucose tolerance discussion. Once the term is pinned down I suspect the disagreement mostly goes away and what is left is small.
Hexarelin and the earlier peptidyl secretagogues have more published human data than the newer ones and a less favourable profile, which is worth knowing before treating "newer" as "better characterised".
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.
Posted with less confidence than the sentence structure implies.
Injection-site reactions are reported more often in this family than for the incretins. Whether that is the compounds or the preparations they are typically supplied in is not established.
Where I part company with post #38, and it is a narrow parting.
Whatever the answer on secretagogues and glucose tolerance turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, invite the correction.
Agreed on all of that, and I have nothing to add to it.
This follows post #38 rather than contradicting it.
Summarising the secretagogues and glucose tolerance thread so far, since it is long and the answer is buried: the first reply has the method, the fourth has the correction to it, and the rest is people agreeing at length.
Evidence quality in the secretagogue literature is honestly weaker than in the incretin literature. Large randomised controlled trials are rare. Most evidence is mechanistic or from small studies. This is why this subcategory has higher sourcing standards than most.
I will take the caveat as seriously as the claim, which is the point of putting it there.
Storage: these are lyophilised short peptides and are generally reasonably stable dry and considerably less so in solution. Reconstituting only what will be used within the period the supplier's own data covers is the conservative approach.
Picking up post #42: that is the part I would want checked first.
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.
Not disagreeing with anyone above, just adding the bit I keep having to look up.
On post #44 — agreed on the reasoning, with one qualification.
Timing arguments in this family generally rest on the assumption that endogenous release is suppressed by circulating glucose and insulin. That is well supported; the practical protocols built on top of it are much less so.
Adding a source would improve this post and I do not have one to hand.
Secretagogues and glucose tolerance is a question about a distribution, not about a value, and treating it as a value is what produces the confident wrong answers.
Reconstitution volumes in this family are often small enough that dead volume in the syringe is a meaningful fraction of the dose. A fixed-needle insulin syringe is worth the trouble here specifically.
Post #48 describes the usual case. This is about the unusual one.
Checked the secretagogues and glucose tolerance claim against the primary source this morning. It survives, with a narrower scope than the version quoted here. Posting the narrower scope.
Collapsed as off-topic by two members at trust level 3 or above
I disagree with the framing of secretagogues and glucose tolerance above, and I think it is a substantive disagreement rather than a terminological one. Setting out why, so it can be checked.
The reasoning depends on an assumption that is doing a lot of work and is never stated. If the assumption holds, the conclusion follows. I do not think it holds generally.
Building on post #50 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.
Two people can read the same figure differently here and both be reasonable.
Reading a rodent study on a secretagogue without over-extrapolating: rodent studies can show a mechanism is plausible. They cannot show magnitude of effect in humans or safety profile in humans. That gap is larger for secretagogues than for incretin agonists because the human evidence is thinner.
Post #52 and I disagree about the size of the effect, not about the direction.
The useful distinction on secretagogues and glucose tolerance is between what was measured and what was inferred from it. Both end up in the same sentence and only one of them has error bars.
Taking post #55 at face value and following it one step further.
Speaking only to secretagogues and glucose tolerance as I have actually seen it, rather than as it is usually described: the effect is real, it is smaller than the thread suggests, and the variance between people is larger than the effect.
I changed my mind about secretagogues and glucose tolerance after someone here asked me for the source and I could not produce one. That is worth saying out loud because it is the ordinary way it happens.
Worth separating two things that post #55 runs together.
The confident answers on secretagogues and glucose tolerance and the well-sourced answers are not the same answers, which is the most useful thing I have learned reading this category.
Collapsed as off-topic by two members at trust level 3 or above
Sensible. I would want the same detail before I acted on it either.