Does Sermorelin increase IGF-1?
Yes, in the older men studied. The interesting questions are how that result was measured, and why several larger claims lead to a different compound.
IGF-1 vs sermorelin
Sermorelin is the administered peptide; IGF-1 is a hormone measured downstream of growth-hormone release. The direct answer to “does sermorelin increase IGF-1” comes from the GHRH(1-29) study in healthy older men. The men’s GH and IGF-1 rose with treatment.
As pharmacology, that result persuades me. A blood result can establish that a hormone pathway responded while leaving strength, memory and lasting health unanswered. Those outcomes need their own measurements.
1992 · Older men and hormone output
Corpas and colleagues studied healthy older men with a mean age of 68 years. Across 14 days, treatment produced dose-related increases in 24-hour GH and IGF-1. At the higher studied amount, those hormone parameters no longer differed significantly from the younger men’s; fasting glucose did not change. The paper’s result concerns restoration of measured hormone levels.
The word “reverses” in the title is striking. Its object is the decreased GH and IGF-1 levels. The same verb attached to “aging” overstates the result, to my mind. The experiment would need a different set of outcomes to carry that claim.
1996 · Growth in children
The multicenter childhood trial enrolled prepubertal children with growth-hormone deficiency. Sermorelin accelerated linear growth during the first year without excessive IGF-1 generation. That belongs beside the historical pediatric indication and diagnostic use.
I rate the childhood clinical case highest among the treatment entries: the problem and measured benefit fit each other. The adult aging argument involves a different population and a different proposed purpose.
1997 · The [Nle27] entry
Khorram and colleagues studied age-advanced men and women for 16 weeks using [Nle27]GHRH(1-29)-NH2, an altered peptide. IGF-I and its carrier protein IGFBP-3 increased; blood pressure and body weight were unaffected. The reported transient rise in blood lipids resolved by the end of the study.
The chemical substitution matters here. This is an adult study in the GHRH family with its own identity and safety observations, rather than a second copy of the native-sermorelin experiment.
2012 · Tesamorelin and cognition
Baker and colleagues enrolled 152 older adults, including 66 with mild cognitive impairment, in a randomized, double-blind, placebo-controlled trial. After 20 weeks of tesamorelin, the trial reported a favorable cognition effect (P=0.03), an IGF-1 increase of 117% within the physiologic range, and a 7.4% reduction in percent body fat. Those results came from tesamorelin treatment.
I admire the cognition trial for testing cognition itself. Calling the treatment sermorelin would make the account less accurate at precisely the point where the evidence becomes interesting. The related brain GABA study also used tesamorelin; GABA is a chemical involved in signalling between nerve cells. The earlier controlled cognition study in healthy older adults reports GHRH treatment without clearly identifying the finished preparation in this record.
Sermorelin benefits and before-and-after results
A sermorelin before-and-after comparison in the older-men study means hormone measurements across 14 days. The first-year childhood result means growth. The 20-week cognition and body-fat findings above belong to tesamorelin. These separate endpoints explain why there is no single research timeline for “sermorelin results.”
Claims about weight loss also draw on tesamorelin reducing visceral fat in people with HIV-associated abdominal fat accumulation. That is a specific drug and clinical setting. A lower percentage of body fat measures composition; it supplies no number of pounds lost. The cited record contains no sermorelin muscle-hypertrophy trial. For adult wellness claims, I share the concern in Blackman’s aging editorial about the distance between hormone changes and established benefit.
Testosterone and combinations
The secretagogue study in men with low testosterone reported increased serum IGF-1. That outcome concerns the growth-hormone pathway; it leaves a direct testosterone effect unresolved.
The popular sermorelin–ipamorelin pairing has a receptor-based rationale, discussed on the comparison page. The cited record offers no clinical efficacy trial of that pairing. It does include diagnostic GHRH(1-29) and GHRP-2 testing in children, which is a different peptide pairing, population and question. A stimulation-test result is a thin foundation for a general adult combination claim.
Somatorelin and capromorelin searches
Some searches arriving here use “somatorelin”; the compound identified in the studies above is sermorelin, GHRH(1-29). That search spelling gives me no basis to attach a different drug’s findings to it.
“Capromorelin in humans” also leads readers here, but the audited reading list contains no capromorelin trial from which to build a human comparison. The comparisons this record can support concern ipamorelin, CJC-1295 and tesamorelin. I prefer an empty catalogue entry to a borrowed result.