In older men sermorelin brought growth hormone and IGF-1 back to the level of young men aged about 26. In a 1992 study, 14 days of injections twice a day were enough for this. In longer studies, people aged 55 to 76 gained strength in some exercises and thicker skin, and men also gained lean mass, better well-being and libido. Below we describe these studies one by one and explain what the result depended on.
What is sermorelin?
Sermorelin is the first section of GHRH, the hormone through which the hypothalamus tells the pituitary to release growth hormone. In research it also appears as GHRH 1-29, because it contains the first 29 amino acids of this hormone. The pituitary responds to it with its own growth hormone, released in pulses, as it naturally is.
In the United States sermorelin was an approved medicine, Geref, used from 1990 for diagnosis and from 1997 to treat growth hormone deficiency in children. The manufacturer withdrew it from the market in 2008. In 2013 the US Food and Drug Administration confirmed that the reason was neither safety nor effectiveness. A comparison with its successor is in the guide on how sermorelin and Mod GRF 1-29 differ.
Why does this matter after 50?
With age we release less and less growth hormone, and IGF-1 falls with it. In the 1992 study older men had lower IGF-1 than young men and shorter pulses of growth hormone release. Their pituitary, however, responded to GHRH just as well as in the young.
This is the core of how sermorelin works. Researchers in Turin pointed out in 1994 that the lack of growth hormone in older age starts in the hypothalamus, which stimulates the pituitary more weakly. Sermorelin gives the pituitary the missing signal, and the pituitary can still respond to it. We write more about this in the guide on what happens to growth hormone after 40.
What did the 1992 study show?
The study was run by the US National Institute on Aging in Baltimore. It included 10 healthy men aged 68 on average and 9 young men aged 26 on average. The older men received GHRH 1-29 under the skin twice a day for 14 days, once at a dose of 0.5 mg and once at 1 mg, with a two-week break in between.
- 0.5 mg dose: all measures rose, but without a significant difference.
- 1 mg dose: a significant rise in mean 24-hour growth hormone, pulse size and IGF-1.
- After the 1 mg dose: no significant differences in these measures between older and young men.
- Safety: no change in fasting blood sugar, blood pressure or blood tests.
The authors concluded that short-term GHRH reverses the age-related fall in growth hormone and IGF-1. In their view longer treatment could improve body composition.
Does sermorelin improve muscle strength?
A 1997 study at Johns Hopkins University tested this. Eleven healthy men aged 64 to 76, with low baseline IGF-1, injected themselves at home with 2 mg of GHRH 1-29 every evening for 6 weeks.
| What was measured | Result after 6 weeks |
|---|---|
| Growth hormone at night | higher mean level and higher pulses |
| Muscle strength | better result in 2 of 6 exercises: upright row and overhead press |
| Muscle endurance | better result in sit-ups |
| IGF-1, body composition, sugar, blood fats | unchanged |
| Side effects | none significant |
The researchers noted that one dose in the evening works less well than several doses during the day. In this study IGF-1 did not rise, while in the 1992 study with two doses a day it did. The researchers also described a change in muscle energy use, consistent with less need for anaerobic metabolism during exercise.
What did 16 weeks of dosing achieve?
The longest of these studies was run by a team at the University of California in La Jolla in 1997. Nine men and ten women aged 55 to 71 received placebo for 4 weeks and then a GHRH 1-29 analogue every evening for 16 weeks. It was the equivalent of sermorelin with one amino acid swapped for norleucine, at a dose of 10 micrograms per kilogram of body weight.
| Result | Men | Women |
|---|---|---|
| Growth hormone at night | 107 percent higher | 70 percent higher |
| IGF-1 | higher after just 2 weeks | higher after just 2 weeks |
| Skin thickness | greater | greater |
| Lean mass | greater | unchanged |
| Insulin sensitivity | better | unchanged |
| Well-being and libido | better | unchanged |
Growth hormone rose as soon as 10 minutes after the injection, and the surge lasted about 2 hours. The effect did not fade through the whole study. IGF-1 rose by 28 percent on average and stayed high for 12 weeks, and towards the end of the study it drifted back towards baseline. The only side effect was a temporary rise in blood fats, which had settled by the end of the study.
Does sermorelin affect immunity?
The same team examined the immune system in the same group. After 16 weeks the number of B lymphocytes rose by 30 percent and their response to stimulation by 50 percent. T lymphocytes responded to stimulation 50 percent more strongly, and the number of cells with the interleukin 2 receptor rose by 70 percent.
The changes appeared in both sexes, without side effects. The authors judged that the GHRH analogue strongly boosts immune function in older people. This is an interesting direction, because with age both the growth hormone axis and immunity weaken.
How does full GHRH given for 3 months compare?
A fuller picture came from a 2004 Mayo Clinic study, although it used the longer molecule GHRH 1-44 rather than sermorelin. Twenty-two men aged 53 to 68 received 1 or 4 mg twice a day for 3 months.
- IGF-1: roughly doubled at both doses.
- 4 mg dose: more lean mass and less belly fat.
- Both doses: faster 30-metre walk and four-flight stair climb.
- Unchanged: leg strength, aerobic capacity and bone density.
- Side effects: frequent reactions at the injection site.
The result suggests that, with the same hormonal axis, dose and dosing frequency matter. A comparison of sermorelin with other GHRH analogues is in the guide sermorelin, Mod GRF 1-29, CJC-1295 and tesamorelin in one table. Sermorelin sold as research material is not the medicine Geref.
Where to buy sermorelin and how much does it cost?
The shop has three variants of sermorelin, all in stock:
| Product | Amount | Price | Price per milligram |
|---|---|---|---|
| Sermorelin Bio-Peptide | 5 mg | 40 EUR | 8 EUR |
| Sermorelin Genheal | 5 mg | 40 EUR | 8 EUR |
| Sermorelin Nouveaux Ltd. | 10 mg | 75 EUR | 7.50 EUR |
All variants are gathered on the sermorelin page. Sermorelin works through the GHRH receptor, so it complements peptides that act through the ghrelin receptor well. How strong this combination was in studies is described in the guide on what studies showed about GHRP-6. The products in the shop are material for laboratory research, not a medicine.
Frequently asked questions
Does sermorelin raise growth hormone in older people?
Yes, in a 1992 study 14 days of 1 mg injections twice a day brought growth hormone and IGF-1 in older men up to the level of young men.
How soon does sermorelin raise IGF-1?
In a 1997 study IGF-1 rose after just 2 weeks of evening injections and stayed high for 12 weeks.
Does sermorelin increase muscle mass?
In a 16-week study a sermorelin analogue increased lean mass in men, and in a 6-week study it improved strength in 2 of 6 exercises.
Is one evening dose enough?
The 1997 researchers judged that one evening dose works less well than several doses during the day. With two doses a day IGF-1 rose more clearly.
How much does sermorelin cost in the shop?
The 5 mg Bio-Peptide and Genheal vials cost 40 EUR each, and the 10 mg Nouveaux Ltd. vial 75 EUR. The 10 mg vial is the cheapest per milligram.
Sources
- Corpas E, Harman SM, Piñeyro MA et al. Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men. Journal of Clinical Endocrinology and Metabolism, 1992, 75(2): 530-535. https://doi.org/10.1210/jcem.75.2.1379256
- Vittone J, Blackman MR, Busby-Whitehead J et al. Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men. Metabolism, 1997, 46(1): 89-96. https://doi.org/10.1016/s0026-0495(97)90174-8
- Khorram O, Laughlin GA, Yen SS. Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women. Journal of Clinical Endocrinology and Metabolism, 1997, 82(5): 1472-1479. https://doi.org/10.1210/jcem.82.5.3943
- Khorram O, Yeung M, Vu L, Yen SS. Effects of [norleucine27]growth hormone-releasing hormone (GHRH) (1-29)-NH2 administration on the immune system of aging men and women. Journal of Clinical Endocrinology and Metabolism, 1997, 82(11): 3590-3596. https://doi.org/10.1210/jcem.82.11.4363
- Veldhuis JD, Patrie JT, Frick K et al. Sustained growth hormone (GH) and insulin-like growth factor I responses to prolonged high-dose twice-daily GH-releasing hormone stimulation in middle-aged and older men. Journal of Clinical Endocrinology and Metabolism, 2004, 89(12): 6325-6330. https://doi.org/10.1210/jc.2004-0430
- Ghigo E, Arvat E, Rizzi G et al. Growth hormone-releasing activity of growth hormone-releasing peptide-6 is maintained after short-term oral pretreatment with the hexapeptide in normal aging. European Journal of Endocrinology, 1994, 131(5): 499-503. https://doi.org/10.1530/eje.0.1310499
- Food and Drug Administration. Determination that GEREF (sermorelin acetate) injection and other drug products were not withdrawn from sale for reasons of safety or effectiveness. Federal Register, 4 March 2013, document 2013-04827. https://www.federalregister.gov/documents/2013/03/04/2013-04827