Sermorelin
Growth Hormone / IGF-1 AxisFDA ApprovedAlso known as: GRF 1-29
Sermorelin acetate is a synthetic 29-amino-acid peptide corresponding to the biologically active N-terminal fragment of human growth hormone-releasing hormone (GHRH 1-29). It was one of the first GHRH analogs to achieve FDA approval — Geref received pediatric approval in 1997 for evaluating and treating idiopathic growth hormone deficiency in children.
Overview
At A Glance
GHRH Receptor Pharmacology…
Mechanism of Action
GHRH Receptor Pharmacology
Sermorelin is a truncated analog — specifically the first 29 amino acids — of the 44-amino-acid native GHRH molecule produced by the arcuate nucleus of the hypothalamus. The 1-29 fragment retains the full biological activity of the parent molecule because the C-terminal residues 30-44 contribute to peptide stability but not to receptor binding or activation (Thorner et al., 1996).
When sermorelin binds the GHRH receptor (GHRHR), a class B G-protein coupled receptor expressed almost exclusively on anterior pituitary somatotrophs, it triggers:
- Gs-protein activation → elevated cyclic AMP → protein kinase A signaling
- Transcriptional upregulation of the GH1 gene and preformed GH granule exocytosis
- Potentiation of the ghrelin/GHS-R1a pathway when ghrelin-mimetics are co-administered
The net effect is a strong, pulsatile release of growth hormone that closely resembles the endogenous nocturnal GH burst of a healthy young adult — something recombinant HGH injections cannot replicate because they bypass the pituitary entirely.
Pulsatility and the Somatostatin Gate
The critical feature of GHRH-driven GH release is that it remains subject to somatostatin tone. Somatostatin — the body's endogenous GH-inhibitor released from the periventricular nucleus — acts as a ceiling on how much GH any given GHRH pulse can elicit. This means sermorelin cannot produce supraphysiological GH levels the way HGH injections can, and it preserves the natural ultradian rhythm of GH secretion across the 24-hour cycle.
Clinical data from Vance et al., 1985 and the original sermorelin dose-response work demonstrated that increasing doses beyond ~500 mcg in a single injection yields diminishing returns — the somatostatin ceiling simply prevents further release regardless of how much GHRH is present at the receptor.
Short Half-Life as a Feature
Native GHRH has a serum half-life of approximately 7 minutes. Sermorelin, bearing an identical amino acid sequence in the active fragment, has only modest stability enhancement and clears with a half-life of 10 to 20 minutes (Walker et al., 1990). This rapid clearance:
- Prevents receptor desensitization that chronic continuous GHRH exposure would cause
- Allows downstream somatostatin pulses to normally suppress GH between cycles
- Mimics the brief 20-30 minute GHRH pulses that occur naturally every 2-3 hours in young adults
This is why sermorelin-induced IGF-1 elevations plateau rather than accumulate the way long-acting analogs like CJC-1295-DAC or MK-677 tend to do. The tradeoff is injection frequency — sermorelin must be dosed daily, whereas long-acting analogs can extend the dosing interval to every few days.
Anabolic Downstream Effects
Sustained nightly sermorelin administration produces a gradual rise in IGF-1 toward the upper-quartile of age-adjusted normal range (Khorram et al., 1997). Secondary anabolic effects documented across clinical trials include:
- Lean body mass increase of 1.2-2.8 kg over 16 weeks in older adults
- Visceral adipose tissue reduction (smaller magnitude than tesamorelin but directionally consistent)
- Improved slow-wave sleep architecture — the phase responsible for >70% of daily GH secretion
- Modest IGF-1 increases typically in the range of +50 to +120 ng/mL from baseline
These effects should be understood as physiologic restoration rather than pharmacologic supraphysiology — sermorelin is working the pituitary back toward a more youthful secretion pattern, not driving it into states the body never naturally inhabits.
Overview
Sermorelin acetate is a synthetic 29-amino-acid peptide corresponding to the biologically active N-terminal fragment of human growth hormone-releasing hormone (GHRH 1-29). It was one of the first GHRH analogs to achieve FDA approval — Geref received pediatric approval in 1997 for evaluating and treating idiopathic growth hormone deficiency in children. Although the branded product was discontinued commercially in 2008 due to market factors unrelated to safety or efficacy, sermorelin has experienced a significant second life through 503B compounding pharmacies that supply it for off-label use in adult growth hormone axis support, anti-aging medicine, and athletic performance contexts.
Sermorelin binds the GHRH receptor (GHRHR) on pituitary somatotrophs and triggers endogenous growth hormone release through the body's native negative-feedback architecture. Because it relies on pituitary reserve rather than bypassing it, sermorelin produces pulsatile GH release that respects somatostatin inhibition — you cannot overshoot the way exogenous recombinant human GH can, and IGF-1 typically rises into the upper quartile of age-adjusted normal rather than into supraphysiological territory. This is the fundamental mechanistic difference that makes GHRH therapy tolerable for long-term use where rhGH use carries more concerning risks.
Its short serum half-life — approximately 10 to 20 minutes in healthy adults — is simultaneously sermorelin's greatest limitation and its most clinically elegant feature. The short window forces once-daily bedtime dosing that aligns with the body's natural nocturnal GH pulse, and it means residual peptide never persists long enough to disturb subsequent endogenous pulses. Modern practitioners frequently choose sermorelin over longer-acting analogs like CJC-1295 DAC specifically because the pulsatile kinetics more closely mimic healthy young physiology.
In research and clinical settings, sermorelin is typically dosed at 200 to 500 mcg subcutaneously at bedtime for adult GH tuning protocols, though historical pediatric GHD protocols used up to 30 mcg/kg/day. Six-month trials in healthy older adults have demonstrated modest but measurable gains in lean body mass, reductions in visceral adiposity, and improvements in sleep architecture — particularly slow-wave sleep depth, which is where the majority of physiologic GH secretion occurs in the first place.
Potential Research Fields
Chemical Information
IUPAC Name
Growth hormone-releasing hormone (1-29) amide
CAS Number
86168-78-7
Molecular Formula
C149H246N44O42S
Molecular Mass
3357.9 g/mol
Dosing & Protocols
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Interactions
Interaction Matrix
Contraindications
Sermorelin is contraindicated or requires extreme caution in:
- Active malignancy — particularly any hormone-responsive cancer (breast, prostate, endometrial) given the theoretical concern that elevated IGF-1 could promote tumor growth
- Strong family history of GH-axis responsive cancers — use only under specialist supervision with close monitoring
- Pregnancy and lactation — no established safety data; avoid
- Known hypersensitivity to sermorelin, GHRH analogs, or any excipient
- Severe untreated sleep apnea — theoretical concern about upper airway soft tissue growth; stabilize with CPAP/APAP before initiating
- Acute critical illness — GH-axis stimulation is inappropriate during sepsis, post-surgical recovery, multiple trauma, or respiratory failure states
- Diabetic ketoacidosis or severe uncontrolled diabetes — resolve the metabolic state first
- Active proliferative retinopathy — relative contraindication; discuss with ophthalmologist
Relative cautions requiring monitoring:
- Borderline fasting glucose or HbA1c — monitor closely; discontinue if deterioration
- History of benign adenomas (pituitary, adrenal, thyroid) — imaging surveillance recommended
- Strong family history of colon polyps — baseline colonoscopy before starting, surveillance per gastroenterology guidance
- Concurrent glucocorticoid therapy — pharmacodynamic interference; GH-axis stimulation is less effective in pharmacologic steroid contexts
Age-related note: Sermorelin has been used in pediatric GHD populations historically with FDA approval, but use in healthy older adults for anti-aging purposes remains off-label and should only be undertaken with informed consent about the limitations of available long-term safety data.
Research Disclaimer
This interaction data is compiled from published research and community reports. It may not be exhaustive. Always consult a healthcare professional before combining compounds.
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| Vendor | Product | Form | Qty | Price | $/mg | Coupon | |
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Sermorelin 5mg | vial | 1 vial● Out of Stock | $39.00BEST | $7.800 | — | Sign in for stock alert |
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Sermorelin 10mg | vial | 1 vial● In Stock | $65.00 | $6.500 | — | |
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Sermorelin 5mg | vial | 1 vial● In Stock | $39.99 | $7.998 | — | |
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Sermorelin 5mg Vial | vial | 1 vial● In Stock | $48.00 | $9.600 | ||
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Sermorelin 2mg | vial | 2mg vial● In Stock | $24.99 | $12.495 | ||
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Sermorelin 5mg | vial | 5mg vial● In Stock | $39.99 | $7.998 |
Tracking since Mar 13, 2026 · 7 data points
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Related Compounds
View AllCJC-1295 (Mod GRF 1-29)
Growth Hormone / IGF-1 AxisPreclinicalCJC-1295 without DAC (also called Modified GRF 1-29 or MOD-GRF 1-29) is a 30-amino-acid analog of the first 29 residues of endogenous Growth Hormone Releasing Hormone (GHRH), with four strategic substitutions (D-Ala² for DPP-4 resistance, Gln⁸, Ala¹⁵, Leu²⁷) that extend its plasma half-life from <2 minutes (native GHRH) to ~30 minutes.
CJC-1295 with DAC
Growth Hormone / IGF-1 AxisPhase 2CJC-1295 with DAC (Drug Affinity Complex) is a modified form of CJC-1295 that incorporates a maleimidopropionic acid (MPA) reactive group at the C-terminus.
GHRP-2
Growth Hormone / IGF-1 AxisPhase 2GHRP-2 (growth hormone-releasing peptide-2), also known as pralmorelin and KP-102, is a synthetic hexapeptide growth hormone secretagogue that was among the first GHRPs developed in the seminal research of Cyril Bowers and colleagues at Tulane University in the late 1980s and early 1990s.
GHRP-6
Growth Hormone / IGF-1 AxisPhase 2GHRP-6 (growth hormone-releasing peptide-6) is a synthetic hexapeptide with the sequence His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 that binds the ghrelin receptor (GHS-R1a) to stimulate endogenous growth hormone release.
Hexarelin
Growth Hormone / IGF-1 AxisPhase 2Hexarelin (also called examorelin) is a potent synthetic hexapeptide growth hormone secretagogue with the sequence His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2.
IGF-1 LR3
Growth Hormone / IGF-1 AxisPhase 2IGF-1 LR3 (Long R3 IGF-1) is a synthetic analog of human insulin-like growth factor 1 modified at two positions to dramatically extend its serum half-life and amplify its tissue bioactivity compared to native IGF-1.
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Related Articles
All PostsResearch Score
198 PubMed studies
Quality Indicators
Data Completeness
100%Research Credibility
Well-researched compound
Quick Facts
Molecular Weight
3357.9 g/mol
CAS Number
86168-78-7
Trial Phase
FDA Approved
Safety Profile
Low RiskCommon Side Effects
- • Injection site redness/swelling
- • Headache
- • Flushing
- • Nausea
Stop Use If
- Active malignancy
- Hypothyroidism (treat first)
- Pituitary tumor
Research Disclaimer
This information is for educational and research purposes only. Not intended as medical advice. Consult a healthcare professional before use.
Frequently Asked Questions
What is sermorelin and how does it work?
Sermorelin is a synthetic 29-amino-acid peptide corresponding to the biologically active N-terminal fragment of GHRH — the hypothalamic hormone that tells your pituitary to release growth hormone. It binds the GHRH receptor on pituitary somatotrophs, triggering a pulsatile release of endogenous GH that respects the body's natural negative feedback architecture. It was originally FDA-approved as Geref in 1997 for pediatric growth hormone deficiency evaluation and treatment, and is now commonly used off-label through 503B compounding pharmacies for adult GH optimization. Unlike recombinant HGH, sermorelin cannot produce supraphysiologic GH levels because somatostatin limits how much GH any single GHRH pulse can elicit.
How is sermorelin different from CJC-1295?
Sermorelin is pure GHRH(1-29) with a 10-20 minute half-life. CJC-1295 without DAC is a stabilized GHRH analog with a modestly longer half-life (~30 minutes), and CJC-1295 DAC adds a DAC linker that extends half-life to ~8 days. Sermorelin and no-DAC CJC-1295 produce pulsatile GH release; CJC-1295 DAC produces continuous GHRH-receptor stimulation that raises baseline GH and IGF-1 more dramatically but eliminates pulsatility. For users prioritizing the most physiologic secretion pattern and minimum receptor desensitization risk, sermorelin is the most conservative choice. For users prioritizing convenience (once or twice weekly dosing), CJC-1295 DAC wins. See the CJC-1295 page for a detailed side-by-side.
What results should I expect from sermorelin?
In the published adult trial data (Khorram 1997 and subsequent work), expect IGF-1 elevations of +50 to +120 ng/mL over 12-16 weeks, a 1-3 kg lean body mass increase, modest reductions in waist circumference, improved slow-wave sleep depth, and subjective improvements in recovery and skin quality. These effects are physiologic restoration — not dramatic transformations. Users expecting results similar to recombinant HGH or anabolic steroids will be disappointed. Sermorelin is best understood as 'restoring the GH secretion pattern of a younger version of yourself' rather than 'giving you supraphysiologic GH levels'.
What is the best sermorelin dosage?
The typical adult protocol is 200-500 mcg subcutaneously once nightly at bedtime. Beginners start at 200-300 mcg to assess tolerance. After 6-12 weeks, responders typically titrate to 300-500 mcg based on IGF-1 response. The single-dose ceiling is around 500 mcg — above that, somatostatin tone prevents further GH release, so higher doses are simply wasted peptide. Some advanced users split the dose into a morning and evening injection, though the bedtime-only approach remains the most common and best-studied. Always dose in a fasted state (3+ hours after last meal) to avoid the insulin-driven somatostatin surge that would blunt GH release.
Can I stack sermorelin with ipamorelin?
Yes — sermorelin + ipamorelin is the classic and most well-established GHRH + GHS combination in the peptide space. The two compounds bind different receptors on the same pituitary somatotrophs (GHRHR and GHS-R1a respectively) and produce a 3-5x amplification of GH pulse amplitude compared to either compound alone (Bowers 1991). Typical stack dose is sermorelin 200-300 mcg + ipamorelin 200-300 mcg in the same subcutaneous injection at bedtime. Ipamorelin's selectivity — it does not elevate cortisol, prolactin, or ACTH — makes it the cleanest ghrelin mimetic to pair with sermorelin. See ipamorelin for full details.
Is sermorelin still FDA approved?
Sermorelin acetate received FDA approval in 1997 as Geref for evaluation of pediatric growth hormone deficiency. The branded product was discontinued commercially in 2008 due to market factors — not safety or efficacy concerns. The peptide itself remains legally available through 503B compounding pharmacies that produce it for physicians who prescribe it off-label for adult GH optimization. This legal-but-compounded status is similar to many other legacy peptides. Clinical use is supervised by medical professionals, and the quality-controlled compounded version is considered equivalent to the original Geref for pharmacologic purposes.
How long does it take sermorelin to work?
The GH and IGF-1 response to a single sermorelin injection occurs within minutes — peak serum GH typically occurs 15-30 minutes post-injection. However, the clinically meaningful body composition and subjective effects take 6-16 weeks of consistent nightly dosing to become apparent. IGF-1 stabilizes at its new elevated setpoint around week 4-6. Lean body mass changes are detectable by week 8-12. Sleep quality improvements often show up earliest — many users report enhanced slow-wave sleep within 2-3 weeks of consistent dosing. Skin changes (improved thickness, hydration) take 12-16 weeks to measure but are usually subjectively noticed earlier.
What are the side effects of sermorelin?
Most side effects are mild and transient. The most common are injection site reactions (erythema, mild itching), facial flushing immediately after injection (fades within 10-20 minutes), and occasionally vivid dreams — which isn't necessarily adverse given that sermorelin improves slow-wave sleep where dreams are consolidated. Less common effects include mild headache, transient hunger (less pronounced than with ghrelin mimetics), and minor fluid retention in the first weeks. Theoretical long-term concerns relate to sustained IGF-1 elevation and cancer risk, though no causal link has been demonstrated in trials to date. Stop if you develop persistent joint pain, carpal tunnel symptoms, or peripheral edema — these suggest IGF-1 is too high.
Does sermorelin cause weight loss?
Sermorelin is not primarily a weight-loss compound. It produces modest reductions in visceral and subcutaneous fat over 12-16 weeks — typically 1-3% body fat in responders — alongside lean mass gains of similar magnitude. Users looking for dramatic weight loss should consider GLP-1 receptor agonists like semaglutide, tirzepatide, or retatrutide. Sermorelin is better understood as a body-composition-optimization tool that modestly improves the fat-to-lean ratio rather than a fat-loss drug. If visceral adiposity specifically is the target, tesamorelin has FDA-approved trial data showing roughly 18% VAT reduction over 26 weeks, which is substantially more aggressive than sermorelin achieves.
Where can I buy sermorelin legally?
In the United States, sermorelin can be prescribed legally by licensed physicians and dispensed through 503B compounding pharmacies. This is the proper legal pathway — the prescribing physician oversees dosing, labs, and safety monitoring. There is also a gray-market research-chemical supply chain outside of medical oversight, but this path carries significant quality-control, sterility, and legal risk. Prescribed compounded sermorelin through a qualified clinic is the only path we recommend. For a curated list of peptide-friendly clinical practices and reliable compounded-peptide pharmacies, see our best vendors guide for 2026.
Research Tools
Related Compounds
View AllCJC-1295 (Mod GRF 1-29)
Growth Hormone / IGF-1 AxisPreclinicalCJC-1295 without DAC (also called Modified GRF 1-29 or MOD-GRF 1-29) is a 30-amino-acid analog of the first 29 residues of endogenous Growth Hormone Releasing Hormone (GHRH), with four strategic substitutions (D-Ala² for DPP-4 resistance, Gln⁸, Ala¹⁵, Leu²⁷) that extend its plasma half-life from <2 minutes (native GHRH) to ~30 minutes.
CJC-1295 with DAC
Growth Hormone / IGF-1 AxisPhase 2CJC-1295 with DAC (Drug Affinity Complex) is a modified form of CJC-1295 that incorporates a maleimidopropionic acid (MPA) reactive group at the C-terminus.
GHRP-2
Growth Hormone / IGF-1 AxisPhase 2GHRP-2 (growth hormone-releasing peptide-2), also known as pralmorelin and KP-102, is a synthetic hexapeptide growth hormone secretagogue that was among the first GHRPs developed in the seminal research of Cyril Bowers and colleagues at Tulane University in the late 1980s and early 1990s.
GHRP-6
Growth Hormone / IGF-1 AxisPhase 2GHRP-6 (growth hormone-releasing peptide-6) is a synthetic hexapeptide with the sequence His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 that binds the ghrelin receptor (GHS-R1a) to stimulate endogenous growth hormone release.
Hexarelin
Growth Hormone / IGF-1 AxisPhase 2Hexarelin (also called examorelin) is a potent synthetic hexapeptide growth hormone secretagogue with the sequence His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2.
IGF-1 LR3
Growth Hormone / IGF-1 AxisPhase 2IGF-1 LR3 (Long R3 IGF-1) is a synthetic analog of human insulin-like growth factor 1 modified at two positions to dramatically extend its serum half-life and amplify its tissue bioactivity compared to native IGF-1.
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