Sermorelin is a synthetic 29-amino-acid fragment of GHRH (growth hormone-releasing hormone) that stimulates the pituitary to release endogenous growth hormone. It preserves the natural pulsatile GH-release pattern rather than replacing it with exogenous HGH, which is why it is often preferred in research protocols studying the GH axis without supraphysiological HGH exposure. It was FDA-approved as Geref for pediatric GH deficiency before being voluntarily withdrawn in 2008. Today it is widely available through 503A compounding pharmacies and the research-peptide channel.
Research notes
How sermorelin works
Sermorelin is the first 29 amino acids of human GHRH — the segment that binds the GHRH receptor on pituitary somatotrophs. Receptor binding triggers cAMP signaling and downstream growth-hormone release. The molecule is degraded rapidly (half-life ~12 minutes), so the clinical effect comes from the pulse of endogenous GH the injection produces, not from sustained sermorelin levels in circulation.
What doses are used in research
Standard research-protocol references cite 100-500 mcg subcutaneous nightly, typically at bedtime to align with the natural overnight GH pulse. Pediatric GH-deficiency clinical practice historically used 30 mcg/kg daily. The bedtime timing is the most consistent feature across protocols.
Why sermorelin is preferred over HGH in some research
Three reasons recur in the literature:
- Preserved pulsatility. Endogenous GH is released in pulses with overnight peaks. Sermorelin preserves this pattern. Exogenous HGH does not.
- Preserved feedback. Negative feedback from IGF-1 still operates because the pituitary is the source. With exogenous HGH, supraphysiological levels can persist beyond what the body would self-regulate to.
- Lower side-effect signal in published studies. Edema, joint pain, and insulin-resistance signals are less consistent with sermorelin than with exogenous HGH at equivalent IGF-1-equivalent doses.
How sermorelin compares to tesamorelin and CJC-1295
The three are all GHRH-pathway interventions but they target different use cases. We cover the sermorelin / tesamorelin comparison in detail at tesamorelin vs sermorelin. The sermorelin / CJC-1295 comparison is covered in CJC-1295 vs Ipamorelin which also touches on the GHRH-analog ladder.
Where buyers source sermorelin
Sermorelin is one of the most-stocked compounds in both the research-peptide vendor pool and the 503A compounding pharmacy channel. Vendor coverage spans every major audited brand on the site. For research-grade purity data see the per-compound leaderboard below.
Related reading
- Tesamorelin vs Sermorelin — head-to-head between the two leading GHRH analogs.
- CJC-1295 vs Ipamorelin — the stack most commonly compared with sermorelin.
- CJC-1295 peptide page — long-acting GHRH analog with different research-protocol applications.
- Tesamorelin peptide page — FDA-approved GHRH analog for HIV-associated lipodystrophy.
- Longevity peptides 2026 overview — the broader cluster sermorelin sits in.
What it's researched for
- growth hormone axis support
- longevity research
- sleep and recovery
Where to source it
ALL 2 VENDORS →2 audited vendors stock Sermorelin, but the price walk hasn't captured a current listing for it. See all 2 vendors →
Frequently asked about Sermorelin
What is sermorelin?
Sermorelin is a synthetic analog of the first 29 amino acids of human GHRH (growth hormone-releasing hormone). It binds the GHRH receptor on pituitary somatotrophs and triggers endogenous growth-hormone release. Because it works through the body's own GH-release pathway, it preserves the pulsatile circadian rhythm of GH secretion rather than producing a flat exogenous-HGH signal.
How is sermorelin different from HGH?
HGH (somatotropin) is exogenous growth hormone — administering it bypasses the pituitary entirely and produces sustained supraphysiological levels. Sermorelin stimulates the pituitary to release its own GH, which preserves the natural pulsatile pattern and the negative-feedback control. The downside is a smaller absolute GH increase. The upside is a more physiological signal with lower side-effect burden in research protocols.
How is sermorelin different from CJC-1295?
Both are GHRH analogs, but CJC-1295 has structural modifications (specifically the DAC, drug-affinity-complex variant) that extend its half-life from sermorelin's ~12 minutes to days. Sermorelin produces a short, physiological GH pulse. CJC-1295 produces sustained GH elevation. Research-protocol use diverges sharply between the two for that reason.
What doses are used in sermorelin research?
Adult research protocols typically cite 100-500 mcg subcutaneous nightly. The bedtime timing aligns with the natural overnight GH pulse, which is when most GH is released physiologically. Pediatric GH-deficiency clinical use historically dosed at 30 mcg/kg daily. These are research-protocol references, not human-use recommendations.
Is sermorelin FDA-approved?
Sermorelin acetate was FDA-approved as Geref in 1990 for pediatric growth-hormone deficiency. The brand was voluntarily withdrawn in 2008 for commercial reasons (not safety), and it remains available through 503A compounding pharmacies. Research-grade sermorelin sold by peptide vendors is the same molecule but is not labeled or distributed for human use.
What's the typical purity of research-grade sermorelin?
Janoshik and Kovera Labs testing in our corpus typically show 99%+ purity by HPLC for sermorelin from audited vendors. Identity is confirmed by mass spectrometry. Per-vendor data is in the leaderboard further down this page.