Sermorelin

What Sermorelin is

Sermorelin consists of the first 29 amino acids of growth hormone-releasing hormone, GHRH. This is the signal with which the hypothalamus tells the pituitary gland to release growth hormone. Sermorelin gives the same command.

The difference from giving growth hormone directly is the heart of the matter. Injecting growth hormone overrides the body’s own system: the level rises and stays up while the body’s own production shuts down. Sermorelin talks to the gland, and the gland releases in its own rhythm, in pulses, mostly at night. On top of that comes a natural brake: the gland only gives what it has.

An approved drug that no longer is one

The product was called Geref and came from the company EMD Serono. There were two approvals: in 1990 as a diagnostic agent that could be used to test whether the pituitary gland can release growth hormone at all, and in 1997 as a treatment for children with growth failure due to growth hormone deficiency. In 2008 the manufacturer stopped distribution, and in 2009 the approvals were withdrawn.

In 2013, four years after the approvals were revoked, the authority published a formal determination: Geref had not been withdrawn for reasons of safety or efficacy. Such determinations have a practical reason. Only if a drug did not disappear because of safety or efficacy may generic versions be approved. Geref disappeared because sales were no longer worthwhile.

Why the advertising claim is true and still misleading

Sales pages state that sermorelin was once approved by the US drug regulator. This sentence is correct, and it is quoted correctly. Nobody is lying here. A statement about children with hormone deficiency is simply being used to claim something about healthy forty-year-olds.

The honest version would read roughly like this: sermorelin was approved to improve growth in children with proven growth hormone deficiency and to test gland function in suspected cases. It was never approved for healthy adults who want to feel younger, and it was never reliably tested for that. When someone advertises with an approval, the next question is therefore always: approved for what, and for whom?

What follows when the level rises

Let us assume sermorelin works exactly as described: the growth hormone level rises, nicely pulsatile, entirely natural. What follows from that? One answer comes from a related substance, MK-677, which also raises growth hormone and IGF-1 levels and was tested in a two-year study in 65 older adults.

The result was split in two. After one year, lean mass was 1.1 kilograms higher, under placebo 0.5 kilograms lower. Strength and function did not improve. Instead, fasting blood glucose rose and insulin sensitivity fell. This is not a quirk of this one study but the recurring result of growth hormone research in healthy people: body composition shifts measurably, performance does not follow.

What the studies show

Approval data on Geref, 1990 and 1997

The data base concerns children with proven growth hormone deficiency and the testing of gland function in suspected cases. That is a very clear, very narrow indication. Studies of sermorelin in healthy adults that could be called reliable do not exist: the substance is old, nobody invested further after the approval studies, and that is exactly why it disappeared from the market.

Two-year study of MK-677 in 65 older adults

MK-677 is a related substance that raises growth hormone and IGF-1 levels. After one year, lean mass was 1.1 kilograms higher, under placebo 0.5 kilograms lower. Strength and function did not improve, fasting blood glucose rose, insulin sensitivity fell. The study says nothing directly about sermorelin, but a great deal about the question of what a raised level is worth.

What is missing in adult humans

For healthy adults there is nothing reliable on sermorelin. There are only a few small, short studies in older people from the 1990s with inconsistent results. In one of them, 11 healthy men between 64 and 76 years received sermorelin for 6 weeks, without a control group: growth hormone rose, IGF-1 and body composition remained unchanged, 2 of 6 strength measures improved. No study on body composition, sleep, recovery or performance worthy of the name, and certainly none over longer periods. The old data concern children with hormone deficiency, at a specific dose, in a specific group, under medical supervision. Transferring them to an adult who injects themselves for months is an extrapolation and not a finding.

Status, approval and legal

The manufacturer stopped distributing Geref in 2008, and the approvals were withdrawn in 2009. The regulatory determination of 2013 stated that the withdrawal did not take place for reasons of safety or efficacy. What is sold today under the name sermorelin comes through pharmacies that compound it individually and through the gray market. No approval exists for the use in healthy adults that is marketed today. In sport, sermorelin is prohibited as a GH-releasing factor (WADA class S2).

Safety

For the approved use in children there was a safety profile, and the authority stated explicitly that safety was not the reason for its disappearance. But that applies to a specific dose, in a specific group, under medical supervision. Added to this is the objection that applies to everything that stimulates growth: growth hormone and IGF-1 promote cell growth, and that is not a good property where tumors exist. For sermorelin in healthy people there are no long-term data on this, neither reassuring nor worrying. There is simply nothing. Anyone using a gray-market product or an individually compounded preparation also faces the question of the identity and purity of the batch.

Sources

• Geref (sermorelin), approval as a diagnostic agent in 1990 and for treatment in children in 1997, EMD Serono
• Federal Register 2013: determination on the market withdrawal, not for reasons of safety or efficacy
• Prakash and Goa, BioDrugs 1999 (sermorelin as the GHRH fragment of the first 29 amino acids)
• Nass et al., Ann Intern Med 2008 (two-year study of MK-677 in 65 older adults, lean mass and insulin sensitivity)
• Vittone et al., Metabolism 1997 (11 healthy older men, 6 weeks, without a control group)
• Sigalos and Pastuszak, Sex Med Rev 2018 (safety and efficacy of GH secretagogues)
• USADA, sermorelin in sport (as of February 26, 2026)