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Compounds · Secretagogues & GH axis · continued

Why pulsatile secretion matters for interpreting secretagogue claims — a second dataset posts 31–60

This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.

CN
c.niemelTL3Regular24 Dec 2024#31

post #30 is right about the mechanism and I think understates the practical bit.

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

1 like 19mo
SF
s.ferreiraTL2 Moderator29 Dec 2024#32
taper_table, post #30: 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. Go to post

What a well-designed human trial of a secretagogue would look like: randomised, placebo-controlled, adequate sample size, IGF-1 as primary outcome, muscle and strength as secondary outcomes, adequate follow-up duration. Very few secretagogue trials meet that description.

7 likes in reply to #30 19mo
OC
o.cousineauTL3Regular2 Jan 2025#33

CJC-1295 with and without DAC: the version with a drug affinity complex binds albumin covalently and persists for days. The version without it does not persist. Supplier labelling frequently does not distinguish them clearly, so confirming which you have is important.

24 likes 19mo
NV
n.vogelTL2 Moderator6 Jan 2025#34

I read post #32 twice before replying, because I had assumed the opposite.

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.

0 likes 19mo
EO
e.okaforTL2 Moderator11 Jan 2025#35
s.vanhecke, post #29: Tesamorelin has an approved indication in HIV-associated lipodystrophy. That is the only compound in this class with a registration-quality evidence base from a proper trial programme. Generalising from that narrow population to healthy adults is a substantial extrapolation. Go to post

Pulsatile secretion matters because growth hormone is secreted in pulses, not continuously. A single post-dose growth hormone level is nearly uninterpretable. Assessing this class properly requires serial sampling or an integrated measure like IGF-1, and almost nothing published online does either.

0 likes in reply to #29 19mo
LT
l.trevinoTL2 Moderator15 Jan 2025#36
p.diallo, post #2: 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. Go to post

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

4 likes in reply to #2 18mo
HK
h.karlsenTL2 Moderator19 Jan 2025 · edited#37

Picking up post #34: that is the part I would want checked first.

IGF-1 as a surrogate: it is a better integrated measure than a spot growth hormone level and it is still a surrogate, with all the caveats that come with surrogates. Stable or rising IGF-1 is not the same as "this is working" in any health-related sense.

18 likes 18mo
CA
c.adebayoTL2 Moderator23 Jan 2025#38

Coming back to post #36, because the follow-up matters more than the original answer.

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.

0 likes 18mo
BP
bench_peakTL3Regular27 Jan 2025#39
r.zielinski, post #20: 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. Go to post

Development history is more informative than speculation: ipamorelin was investigated clinically for post-operative ileus and was not taken forward to registration. That it was not brought to market tells you something about the cost-benefit calculation that any amount of forum enthusiasm does not.

7 likes in reply to #20 18mo
MN
m.ndiayeTL2 Moderator31 Jan 2025#40

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.

17 likes 18mo
CO
c.okaforTL3Regular4 Feb 2025#41
a.silva, post #23: What a well-designed human trial of a secretagogue would look like: randomised, placebo-controlled, adequate sample size, IGF-1 as primary outcome, muscle and strength as secondary outcomes, adequate follow-up duration. Very few secretagogue trials meet that description. Go to post

Worth separating two things that post #37 runs together.

Secretagogues and glucose tolerance: there is a mechanistic concern that sustained growth hormone elevation might impair glucose tolerance. The clinical relevance of this concern in practice is not well established.

0 likes in reply to #23 18mo
SG
s.girardTL2 Moderator8 Feb 2025#42

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.

0 likes 18mo
CC
crossref_checkTL3Wiki editor12 Feb 2025 · edited#43

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

19 likes 17mo
FD
f.danquahTL2 Moderator16 Feb 2025#44
n.vogel, post #34: I read post #32 twice before replying, because I had assumed the opposite. 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… Go to post

Secretagogues and glucose tolerance: there is a mechanistic concern that sustained growth hormone elevation might impair glucose tolerance. The clinical relevance of this concern in practice is not well established.

8 likes in reply to #34 17mo
CL
coldchain_liuTL320 Feb 2025#45
MN
m.nascimentoTL2 Moderator24 Feb 2025#46

Pulsatile secretion matters because growth hormone is secreted in pulses, not continuously. A single post-dose growth hormone level is nearly uninterpretable. Assessing this class properly requires serial sampling or an integrated measure like IGF-1, and almost nothing published online does either.

0 likes 17mo
LE
logbook_erinTL3Regular28 Feb 2025#47

Tesamorelin has an approved indication in HIV-associated lipodystrophy. That is the only compound in this class with a registration-quality evidence base from a proper trial programme. Generalising from that narrow population to healthy adults is a substantial extrapolation.

26 likes 17mo
PO
p.ostergaardTL2 Moderator4 Mar 2025#48
s.girard, post #42: 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. Go to post

Picking up post #45: that is the part I would want checked first.

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

12 likes in reply to #42 17mo
VS
v.szaboTL3Analytical chemist8 Mar 2025#49
lc_gradient, post #17: Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up. Go to post

CJC-1295 with and without DAC: the version with a drug affinity complex binds albumin covalently and persists for days. The version without it does not persist. Supplier labelling frequently does not distinguish them clearly, so confirming which you have is important.

4 likes in reply to #17 17mo
OV
o.vukovicTL2 Moderator12 Mar 2025#50
e.roos, post #6: This follows post #3 rather than contradicting it. Pulsatile secretion matters because growth hormone is secreted in pulses, not continuously. A single post-dose growth hormone level is nearly uninterpretable. Assessing this class properly requires serial sampling or an integrated measure like IGF-1, and almost nothing published online… Go to post

post #49 is right about the mechanism and I think understates the practical bit.

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.

0 likes in reply to #6 17mo
LC
lu.cabreraTL2 Moderator16 Mar 2025#51
e.okafor, post #35: Pulsatile secretion matters because growth hormone is secreted in pulses, not continuously. A single post-dose growth hormone level is nearly uninterpretable. Assessing this class properly requires serial sampling or an integrated measure like IGF-1, and almost nothing published online does either. Go to post

This follows post #48 rather than contradicting it.

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.

2 likes in reply to #35 16mo
JS
j.sorensenTL2 Moderator20 Mar 2025#52

What a well-designed human trial of a secretagogue would look like: randomised, placebo-controlled, adequate sample size, IGF-1 as primary outcome, muscle and strength as secondary outcomes, adequate follow-up duration. Very few secretagogue trials meet that description.

8 likes 16mo
AA
an.adeyemiTL2 Moderator24 Mar 2025 · edited#53

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.

20 likes 16mo
VS
v.salgadoTL2 Moderator28 Mar 2025#54

Development history is more informative than speculation: ipamorelin was investigated clinically for post-operative ileus and was not taken forward to registration. That it was not brought to market tells you something about the cost-benefit calculation that any amount of forum enthusiasm does not.

0 likes 16mo
JM
j.mwangiTL4 Moderator31 Mar 2025#55
s.ferreira, post #32: What a well-designed human trial of a secretagogue would look like: randomised, placebo-controlled, adequate sample size, IGF-1 as primary outcome, muscle and strength as secondary outcomes, adequate follow-up duration. Very few secretagogue trials meet that description. Go to post

Picking up post #52: that is the part I would want checked first.

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.

4 likes in reply to #32 16mo
EK
e.kuuselaTL2 Moderator4 Apr 2025#56

Coming back to post #54, because the follow-up matters more than the original answer.

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.

13 likes 16mo
JC
j.castellanosTL2 Moderator8 Apr 2025#57

Development history is more informative than speculation: ipamorelin was investigated clinically for post-operative ileus and was not taken forward to registration. That it was not brought to market tells you something about the cost-benefit calculation that any amount of forum enthusiasm does not.

27 likes 16mo
CR
c.ramosTL2 Moderator12 Apr 2025#58
m.achebe, post #21: Coming back to post #19, because the follow-up matters more than the original answer. 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… Go to post

Two things before anyone answers the substance.

First, the context in the first post is clear and specific. Second, the question is framed so that an answer can actually address it. Both are the norm here and both matter more than they sound.

0 likes in reply to #21 16mo
HF
h.fonsecaTL2 Moderator15 Apr 2025#59

Secretagogues and glucose tolerance: there is a mechanistic concern that sustained growth hormone elevation might impair glucose tolerance. The clinical relevance of this concern in practice is not well established.

8 likes 15mo
VK
v.klausenTL3Regular19 Apr 2025 · edited#60
s.girard, post #42: 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. Go to post

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.

19 likes in reply to #42 15mo