Sermorelin Before and After: What the Trials Actually Measured

In the adult studies, the reliable "after" is a blood test: growth hormone rises within days and IGF-1 follows within about two weeks. Changes in body fat, muscle and sleep were small, inconsistent, or not measured at all. The two registered trials built to answer the aging question were both terminated before they produced any data.

What "before and after" means for a growth hormone secretagogue

Sermorelin is GHRH(1-29), the first 29 amino acids of growth hormone-releasing hormone. It does not supply growth hormone. It asks the pituitary to release its own, and the liver then makes more IGF-1 in response. Our sermorelin page covers the molecule and its full trial record.

That chain gives "before and after" three possible meanings, and they are not equally well measured:

• The hormone. Growth hormone and IGF-1 in the blood. This is what the studies measured most often and most reliably.
• The body. Fat mass, lean mass and strength, measured by scan or by a weight on a bar. A handful of small adult studies measured this.
• The experience. Energy, sleep, skin and mood. This is what most before-and-after photos imply, and it is the least measured of the three.

The first is a surrogate. It shows the drug reached its target, not that anything a reader cares about changed. Our piece on surrogate endpoints explains why that gap matters.

What the adult studies measured

These are the studies that gave a GHRH peptide to healthy older adults for weeks and then measured something beyond a single hormone test. They are small, and only one used a placebo at all, as a four-week run-in before the drug.

The first study was about the hormone. Corpas and colleagues gave healthy men in their late sixties GHRH(1-29) twice daily for 14 days at a lower and a higher dose. At the higher dose, their 24-hour growth hormone and IGF-1 rose to the point where they no longer differed from the young men's¹. Body composition was not measured. The authors wrote only that prolonged treatment could improve it.

The second study was the first to look for the body change, and did not find it. Vittone and colleagues had 11 men give themselves a single nightly injection for six weeks. Nighttime growth hormone release went up. IGF-1 did not change. Two of six strength measures improved, the upright row and the shoulder press, along with an abdominal-crunch endurance test. Weight, body mass index, waist-to-hip ratio, and DEXA measures of muscle and fat did not change².

The third study ran longest. Khorram and colleagues gave 19 adults a placebo injection nightly for four weeks, then the GHRH analog nightly for 16 weeks. Skin thickness increased in both men and women. Lean body mass increased in the men only, and nothing else in body composition or bone density changed in either sex. Men reported better general well-being and libido. Sleep quality was unaffected in both sexes³.

What changed, and when

Put the three studies on one timeline and the pattern is consistent: the hormone moves first and fastest, and the body follows weakly or not at all.

1. Complete

   Days 1 to 14

   Growth hormone rises after each injection. In Khorram's study IGF-1 was up within two weeks; in Corpas's, IGF-1 rose only at the higher dose.

2. Complete

   Week 6

   With one nightly injection, Vittone found higher nighttime growth hormone but no change in IGF-1, weight or DEXA fat and muscle. Two of six strength tests improved.

3. Complete

   Weeks 12 to 16

   Khorram's IGF-1 stayed up through week 12 and drifted back toward baseline by week 16. Men gained lean mass; women did not. Skin thickness rose in both.

4. 4 — Not reached

   Six months and beyond

   The trials built to measure this were terminated before any participant finished. See below.

Two details in that timeline are easy to miss. In Khorram's study, IGF-1 had started falling back toward baseline by week 16 while the injections continued³. And in Vittone's, one injection a night was not enough to lift IGF-1 at all. The authors concluded that a single nightly dose was less effective than several doses a day².

The two aging trials that were terminated

Two registered phase 2 trials set out to answer the question these small studies left open: does months of GHRH change muscle, fat and function in older adults?

NCT00807365 planned six months of GHRH in the elderly, with change in lean body mass as its primary outcome. It enrolled 5 people and was terminated. The reason recorded in the registry is "PI left JHU." The posted results show no participant completed, and no outcome data was collected⁵.

NCT01410799 planned three months of GHRH in adults 65 and older, measuring strength, lean mass, glucose handling and a six-minute walk. It enrolled 13 people and was terminated with the reason "Funding ended." Its posted results also show no data analyzed. One participant of the 13 reported fatigue⁶.

Neither trial failed. Neither trial answered anything. Both stopped for administrative reasons, so the question they were built to settle is still open.

The aging trial that finished used a different molecule

One large aging trial of a GHRH peptide did finish. SMART, registered as NCT00257712, enrolled 151 adults and completed⁷. Its published report describes 152 adults aged 55 to 87, some with mild cognitive impairment, randomized to a daily bedtime injection or placebo for 20 weeks. IGF-1 rose 117%. Percent body fat fell 7.4%. Cognition scores favored the drug. Adverse events, all mild, were reported by 68% of treated adults against 36% on placebo⁴.

The drug in SMART was tesamorelin, a stabilized analog of the full 44-amino-acid GHRH. It is not sermorelin, and its results do not transfer. When a sermorelin page quotes a 7% fall in body fat, check which molecule it came from. Our sermorelin vs. tesamorelin comparison sets the two records side by side.

What was never measured

Across the adult studies above, these are the outcomes a before-and-after photo implies that no controlled study of sermorelin itself measured:

• Skin appearance. Khorram measured skin thickness with calipers. That is not wrinkles, tone or photographs.
• Sleep. Khorram asked about sleep quality by questionnaire and found no change in either sex³. No study here measured sleep in a lab.
• Fat loss in a placebo-controlled sermorelin trial. The only placebo-controlled body-fat result in this group came from tesamorelin.
• "Anti-aging." No study defined it, and none measured it.
• Anything past 20 weeks. The trials designed to go longer were terminated.

The broader growth-hormone secretagogue evidence follows the same pattern across the class: IGF-1 moves reliably, and outcomes often do not. Sermorelin is often sold alongside CJC-1295 or ipamorelin, and our page on CJC-1295 and ipamorelin covers what each of those was actually tested for.

Where sermorelin stands, and what you would be buying

Sermorelin was an FDA-approved drug. Drugs@FDA lists Geref under two applications held by EMD Serono, and every product under both is marked Discontinued⁸. What is sold today is compounded, which means it is not the product the studies above tested. Our explainer on why compounded is not the trial drug covers what that difference does and does not mean.

If you are weighing it anyway, set your expectations by the studies: a measurable rise in IGF-1 is likely, and a visible change in the mirror is not something any controlled sermorelin study showed. Our sermorelin provider comparison lists the companies that prescribe it and counts how many of each one's claims a human trial actually supports.