Quick answer: the clearest sermorelin results come from children with growth hormone deficiency, whose growth rate rose from 4.1 to 8.0 cm a year after 6 months of nightly injections.[1] In healthy older men, sermorelin raised growth hormone and IGF-1, but changes in muscle, fat and strength were small or absent.[2][3] No study has measured anti-aging results or used before-and-after photos.
This guide walks through what each study actually measured, how fast changes appeared, what happened after stopping, and how to judge claims you see online. For background, see our sermorelin profile and the growth hormone peptides hub.
What sermorelin is
Sermorelin is a lab-made copy of the first 29 amino acids of growth hormone-releasing hormone (GHRH). It prompts the pituitary gland to release growth hormone, which then raises IGF-1, the hormone behind many of growth hormone’s effects.[10] It was sold as Geref, approved for children with growth hormone deficiency and as a diagnostic test, and discontinued in 2008. FDA later determined it was not withdrawn for safety or effectiveness reasons.[13]
Results in children with growth hormone deficiency
This is where sermorelin was tested most carefully, because it was the approved use.
| Study | Who | Dose | Growth rate before | Growth rate on treatment |
|---|---|---|---|---|
| Geref International Study[1] | 110 children with growth hormone deficiency | 30 mcg/kg nightly | 4.1 cm/year | 8.0 at 6 months, 7.2 at 12 months |
| UK, after cranial radiation[8] | 9 children | 15 mcg/kg twice daily | 3.3 cm/year | 6.0 at 12 months |
| London, idiopathic short stature[9] | 18 children | 20 mcg/kg twice daily | 4.8 cm/year | 7.2 at 12 months |
| Shanghai, vs growth hormone[7] | 60 children | 30 or 60 mcg/kg/day | Not given | 9.2 to 9.3 vs 14.6 on growth hormone |
Key results:
- 74% were good responders at 6 months in the Geref study, and bone age did not run ahead of height.[1] That study was open-label, with no placebo group.
- Growth hormone itself worked better. In Shanghai, children on growth hormone grew about 5 cm a year more, and IGF-1 on sermorelin rose at first and then fell back to pre-treatment levels.[7]
- Higher doses did not help more. Doubling the dose from 30 to 60 mcg/kg made no significant difference in growth.[7]
Results in older adults
Most online interest is in adults, but the adult studies were small and short.
Hormone levels
In a National Institute on Aging study, 10 healthy older men injected 0.5 mg or 1 mg twice daily for 14 days each. Only the 1 mg dose significantly raised 24-hour growth hormone and IGF-1, bringing them to levels similar to 9 young men. Fasting glucose and blood pressure did not change.[2]
Muscle, fat and strength
- Sermorelin, 6 weeks: 11 men aged 64 to 76 injected 2 mg nightly. Nighttime growth hormone rose, but IGF-1 did not. Body scans showed no change in muscle or fat, and weight did not change. Two of six strength measures (upright row and shoulder press) and an abdominal endurance test improved.[3]
- A related analog, 16 weeks: 19 adults aged 55 to 71 injected a modified GHRH fragment, not sermorelin itself. IGF-1 rose within 2 weeks but drifted back toward baseline by week 16. Skin thickness increased in both sexes; lean mass, insulin sensitivity, well-being and libido improved in men only. Body fat and bone density did not change.[4]
The authors of the 6-week study concluded that single nightly doses were less effective than multiple daily doses.[3]
Thinking and memory
In 89 healthy older adults, six months of daily GHRH improved scores on several thinking tests compared with placebo.[5] The abstract does not say which GHRH form was used, so this result may not apply to sermorelin.
Sleep
In young men, a single small IV dose of GHRH given late in the night increased deep (slow-wave) sleep almost tenfold.[6] This was a research dose given into a vein during sleep, not a nightly injection schedule.
Limits of the evidence
Before reading too much into any of these results, keep their size and design in mind:
- Small groups. The adult studies enrolled 10 to 19 people each, and the sermorelin studies in adults included only men.[2][3]
- Short courses. The sermorelin studies in adults lasted 2 to 6 weeks, and the related GHRH studies 16 weeks to 6 months, so long-term benefits and risks are unknown.[2][3][4][5]
- Hormone levels, not health outcomes. Most studies measured growth hormone and IGF-1. None measured falls, fractures, disease or lifespan.
- Few controls. The main pediatric trial had no placebo group.[1]
How fast results appear
| What changes | When it was seen |
|---|---|
| Growth hormone pulse | Within minutes; lasted about 2 hours with a related analog[4] |
| IGF-1 in older men | After 2 weeks of 1 mg twice daily[2] |
| IGF-1 with a related analog | Within 2 weeks[4] |
| Growth in children | Clear at 6 months[1] |
| Lean mass in men (analog) | After 16 weeks[4] |
What happens after stopping
In the London short-stature study, growth slowed below its pre-treatment rate during the first 3 months off therapy, then returned to the old rate by 6 to 12 months.[9] No published study has followed adults after stopping, so it is not known how long any adult effects last.
Sermorelin before and after: how to judge claims
Searches for sermorelin before and after photos are common, but none of the published studies used photos as an outcome. When you see a dramatic transformation, consider:
- Other causes. Diet, training, weight loss, lighting, posture and other drugs, including testosterone, can all change appearance.
- What studies found. Controlled studies in older men found no change in body fat or muscle on body scans after 6 weeks of sermorelin.[3]
- Product uncertainty. A 2026 endocrine review highlighted uncertainty about product composition, dose and stacking in unregulated supply chains.[12]
For a broader look at how long peptide effects take, see our peptide therapy results timeline.
Side effects seen in these studies
- Temporary facial flushing and pain at the injection site were the most common effects in the Geref program.[10]
- Most children in the Shanghai trial developed antibodies to sermorelin.[7]
- Fasting glucose and insulin rose in the London study.[9]
See our sermorelin side effects guide for the full picture.
How sermorelin compares
Sermorelin is short-acting. Tesamorelin vs sermorelin compares it with an approved GHRH drug that has large trials, and CJC-1295 vs sermorelin compares it with a long-acting analog. For doses, see sermorelin dosage, and for oral forms, see sermorelin tablets and troches.
Questions to ask a clinician
- What result are we aiming for, and how will we measure it?
- Which study supports this dose and schedule?
- Will you check IGF-1 and fasting glucose before and during treatment?
- What happens if I stop?
- Is there an FDA-approved option for my condition?
Talk to a licensed clinician before starting any hormone-related treatment.
