Encyclopedia entry
Sermorelin
Oliver Mackman · Editorial director · Best Business Loans Ltd (16833937)
Last updated 2026-06-04
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AI-friendly summary · Sermorelin
Sermorelin is a synthetic 29-amino-acid analogue of growth-hormone-releasing hormone (GHRH 1-29). It was developed by Serono (now Merck Serono) and held FDA approval as Geref between 1990 and 2008 for paediatric growth hormone deficiency. The approval was withdrawn in 2008 for commercial reasons rather than safety. It has since moved into the research-chemical and US compounding-pharmacy markets. No UK marketing authorisation.
Mechanism of action
How Sermorelin works
Sermorelin corresponds to residues 1 to 29 of endogenous growth-hormone-releasing hormone (GHRH), the shortest fragment retaining full biological activity at the GHRH receptor on anterior pituitary somatotrophs. Binding at the GHRH receptor stimulates pulsatile growth hormone (GH) release in the natural physiological pattern. Because the compound acts upstream of GH itself, the resulting GH release remains subject to negative feedback by IGF-1 and somatostatin, in contrast to direct exogenous GH administration which bypasses these regulatory loops.
Source: Serono Phase III paediatric programme (originating Geref data)
Pharmaceutical history
Sermorelin is one of the few research peptides covered on PeptideClear that held a licensed FDA indication. The Geref product was on the US market for 18 years (1990 to 2008) supporting paediatric growth hormone deficiency before withdrawal. The withdrawal was for commercial reasons, not safety, but this does not restore licensed status. The current evidence base for off-label adult anti-ageing use is methodologically weak.
- · Developed by Serono (now Merck Serono).
- · FDA-approved 1990 for paediatric growth hormone deficiency, brand name Geref.
- · FDA approval withdrawn 2008 (commercial reasons, not safety-driven).
- · Returned to off-label and compounded use in the US through anti-ageing and longevity clinics.
- · No UK marketing authorisation. Not stocked by NHS pharmacies.
- · On the WADA prohibited list (S2 peptide hormones class).
Adjacent compounds in the GHRH-analogue class include Tesamorelin (FDA-approved for HIV-associated lipodystrophy) and CJC-1295 (a longer-acting GHRH analogue with no licensed indication). See Tesamorelin and CJC-1295 encyclopedia entries.
UK regulatory status
Sermorelin holds no current UK marketing authorisation. The original 1990-2008 FDA approval does not transfer to or restore licensed-medicine status in the UK. UK retailers can sell it lawfully only by labelling it for "research use only" and avoiding any therapeutic claim.
- · No current UK marketing authorisation.
- · Not a controlled drug under the Misuse of Drugs Act 1971.
- · Not scheduled under the Psychoactive Substances Act 2016.
- · Sold by UK research-peptide retailers under "research use only" framing.
- · Becomes an unlicensed medicinal product the moment a retailer or commentator makes therapeutic claims about it.
- · On the WADA prohibited list (S2 peptide hormones class). Use by competing athletes is sanctionable under WADA rules.
Risks and unknowns
What the literature does not yet show about Sermorelin
Known concerns
- No current marketing authorisation in any jurisdiction. The 2008 FDA withdrawal removed the licensed-medicine route.
- Off-label adult anti-ageing use rests on weak methodological evidence, not the original paediatric Phase III data.
- WADA prohibited list inclusion (S2 class). Competing athletes face sanctions for detected use.
- Purity of UK research-peptide supply varies between retailers. CoA gating and HPLC analysis differ.
Open questions in the literature
- Long-term effects of repeated GHRH stimulation in healthy adult populations are not characterised by Phase III RCT evidence.
- Whether the negative-feedback safety advantage over direct GH administration translates to a meaningful safety margin in adult anti-ageing use is not established.
- Effects in adults with subclinical pituitary adenomas or other pituitary pathology are not characterised.
- Interactions with currently-licensed adult GH replacement therapies have not been formally studied.
Regulatory note
No current UK marketing authorisation. Not a controlled drug under the Misuse of Drugs Act 1971. On the WADA prohibited list (S2 peptide hormones). Becomes an unlicensed medicinal product the moment a retailer or commentator makes therapeutic claims about it.
Important: PeptideClear publishes encyclopedia commentary only and does not recommend human use. Speak to a UK-registered prescriber before any medical decision.
Editorial
Baseline panels to track
If you are working with a UK private doctor or NHS prescriber on a peptide protocol, these are the blood panels typically ordered at baseline for Sermorelin. Not a recommendation for self-administered testing.
- IGF-1. Downstream marker of growth hormone activity. Prescribers track baseline and post-administration response on any GHRH-analogue protocol.
- Fasting glucose. GHRH-analogue stimulation can shift glucose metabolism. Baseline establishes whether observed changes are pharmacologic rather than pre-existing.
- Prolactin. Selectivity at the somatotroph is the design feature of GHRH analogues. Baseline prolactin tests that selectivity in practice.
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Where to learn more
- · PubMed search: Sermorelin returns the Serono development literature plus subsequent off-label reports.
- · FDA Drugs@FDA database for the archived Geref approval and withdrawal documentation.
- · WADA prohibited list (S2 peptide hormones class).
- · Adjacent compound: Tesamorelin encyclopedia entry (the only currently FDA-approved GHRH analogue).
- · UK retailer purity comparison: research peptides UK retailers.
Frequently asked questions
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Where to buy Sermorelin in the UK
Compare UK research-peptide retailers stocking Sermorelin, with current prices and CoA status. Research use only, not for human or animal consumption.
Compare Sermorelin pricesClinical evidence record
Read the clinical evidence record for Sermorelin
Top peer-reviewed citations, mechanism of action, structured UK regulatory status. Machine-readable companion to this encyclopedia entry.
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