Formerly FDA-approved for paediatric GH deficiency [1]
Geref held approval for idiopathic growth hormone deficiency in children, with efficacy on growth velocity — a completed regulatory review.
PrecisePep/Peptide Library/Sermorelin
Growth Hormone & Anabolic Support
Sermorelin
GHRH(1-29) · Geref® · sermorelin acetate
The original GHRH fragment — once an FDA-approved diagnostic and paediatric growth agent, withdrawn commercially rather than for safety, and now the most compounded GH secretagogue in the United States.
00 Overview
Sermorelin is the honest baseline for this whole category. It is simply the first 29 amino acids of human GHRH — the shortest fragment that retains full biological activity, with no engineering applied. It was approved by the FDA as Geref for paediatric growth hormone deficiency and used as a diagnostic agent for GH stimulation testing.
It was withdrawn from the US market in the 2000s for commercial reasons rather than on safety grounds, which is an important distinction: unlike most compounds in this library, sermorelin has been through regulatory review and passed. That history is why it remains the most widely compounded GH secretagogue in the United States and appears in legitimate anti-ageing clinic practice.
Its weakness is pharmacokinetic. Native GHRH(1-29) is cleaved rapidly by dipeptidyl peptidase-IV, giving a half-life of ten to twenty minutes. That is the problem CJC-1295 no DAC was engineered to solve with four substitutions. Sermorelin produces a shorter, smaller pulse — which some argue is more physiological and others argue is simply less effective.
Withdrawn is not the same as rejected
A drug pulled for commercial reasons carries a completed safety review that an unapproved research chemical does not. Sermorelin is the one GH secretagogue where "it was approved once" is a true and relevant statement — and it is also the reason it, rather than CJC-1295, is what compounding pharmacies actually dispense.
// Mechanism of action
GHRH receptor agonism. Binds the pituitary GHRH receptor and stimulates synthesis and pulsatile release of endogenous GH. Because it is the native sequence, it does exactly what endogenous GHRH does, for a shorter time.
Preserved feedback and pulsatility. Acting upstream keeps somatostatin feedback intact — the axis can still refuse. This is the standard safety argument for secretagogues over exogenous GH, and it applies most cleanly to the unmodified native fragment.
Rapid DPP-IV degradation. Cleavage at the Ala²-Asp³ bond destroys activity within minutes. Every engineered GHRH analogue — Mod GRF(1-29), tesamorelin — exists to address this.
Requires an intact pituitary. Sermorelin stimulates the gland to release its own GH. Where the axis is disrupted, it does nothing — which is precisely why it works as a diagnostic agent.
01 Reported benefits
Effects that have been reported. A study-tier entry means a result was published — not that the effect is established, reproducible, or transferable from a rodent to a person.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Established diagnostic use in GH stimulation testing [1]
Used to assess pituitary GH reserve, which is a direct clinical demonstration that it does what it claims at the pituitary.
Increases GH and IGF-1 in adults [2]
Demonstrated in clinical pharmacology work, with a smaller and shorter response than the engineered analogues.
Withdrawn for commercial rather than safety reasons [1]
The market withdrawal is frequently mischaracterised. It carries a different meaning from a compound that failed review or was pulled for harm.
No adult body-composition outcome trials
The use it is actually put to — improving body composition and recovery in healthy adults — has not been established in trials.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Restoring age-related GH decline
The anti-ageing clinic rationale. GH output does decline with age; whether restoring pulse amplitude produces meaningful clinical benefit in healthy adults is unproven.
More physiological than engineered analogues
A genuine argument: the native sequence with a native duration should most closely reproduce endogenous signalling. It is also indistinguishable from an argument for a weaker effect.
Improved sleep and recovery
The standard GH-axis claims, inferred rather than measured in this population.
Lower IGF-1 exposure than long-acting analogues
Follows from the shorter pulse, and is a real advantage if the concern is cumulative IGF-1.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Milder and shorter-acting than CJC-1295
The consistent community comparison, and exactly what the pharmacokinetics predict.
Improved sleep depth
The usual GH-axis report, reported as subtler here.
Less water retention than other secretagogues
Frequently reported, consistent with a smaller total GH exposure.
Considered outdated by the community
Often dismissed in favour of engineered analogues — which trades a completed regulatory review for a bigger pulse.
02 Adverse effects & risks
Adverse effects, contraindications and unknowns. The grey-market tier is where under-reporting is worst: uncontrolled use produces no systematic safety surveillance at all, so absence of a reported harm is not evidence of safety.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Injection-site reactions the principal adverse effect [1]
Reported in the approved paediatric use; systemic events uncommon.
Flushing, headache and dizziness [2]
Reported at higher doses and with rapid administration, consistent with vasoactive GHRH effects.
GH-axis class effects apply [3]
Insulin resistance, fluid retention and arthralgia accompany sustained GH elevation regardless of the upstream stimulus — though a smaller pulse means less of all of it.
Contraindicated in active malignancy by class logic [3]
The standard GH-axis consideration, reflected in approved GH-axis labelling.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
IGF-1 elevation with sustained use
Lower than with long-acting analogues but not absent, and still worth measuring.
Ineffective where the pituitary axis is impaired
Not a safety risk so much as a wasted intervention — and a reason baseline assessment matters.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Flushing shortly after injection
Common and transient.
Mild injection-site reactions
The usual complaint.
Little or no perceptible effect
Reported more often than for the engineered analogues, consistent with the shorter pulse.
03 Dosing ranges
Figures below are documented, not recommended. Study ranges come from published protocols in the stated model; grey-market ranges are what the research community reports using and carry no safety validation of any kind.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Nightly, fasted, at bedtime
The approved timing, and mechanistically correct — insulin suppresses GH release, and the largest physiological pulse is early in slow-wave sleep.
Higher doses than the engineered analogues
Follows from the shorter half-life. Community figures reflect this and are typically an order of magnitude above CJC-1295 doses.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
200–500 mcg nightly, fasted
The standard community and compounding-clinic range.
1 mg nightly
Higher-end use, closer to the historically approved weight-based dosing in adults.
Paired with ipamorelin
The two-receptor pairing, exactly as with CJC-1295.
| Approach | Dose | Frequency | Timing |
|---|---|---|---|
| Standard | 200 – 300 mcg | Nightly | Fasted, bedtime |
| Higher-end | 500 mcg – 1 mg | Nightly | Fasted, bedtime |
| With ipamorelin | 200 – 300 mcg | Nightly | Same injection, fasted |
04 Synergy & interactions
Combination effects. Almost no peptide combination has been studied as a combination in humans; stack logic is overwhelmingly mechanistic inference and community practice. Each linked compound has its own page.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
GHRH + ghrelin-mimetic co-stimulation [2]
Established pharmacology, applying to sermorelin as much as to any GHRH analogue.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Sermorelin + ipamorelin
Two receptors, one pulse — the same logic as the CJC pairing with a shorter GHRH arm.
Redundant with CJC-1295 or tesamorelin
All GHRH analogues at the same receptor. Combining them raises the GHRH dose without adding a mechanism.
Possible component of the Triple GH Blend
If a triple blend contains sermorelin alongside CJC-1295, it contains two GHRH analogues competing for one receptor.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Paired with ipamorelin in clinic protocols
The common compounded combination in US anti-ageing practice.
05 Protocols
Whole schedules — dosing, titration, cycle length, and off-time — as documented in trials, as proposed from mechanism, and as circulated in the research community. Reproduced for study and comparison only.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Approved paediatric GH deficiency regimen [1]
Weight-based nightly subcutaneous dosing with growth-velocity endpoints and monitoring.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
IGF-1 guided and cycled
The transferable practice from approved GH-axis medicine.
Assess the axis before assuming a response
Sermorelin requires an intact pituitary. In someone whose axis is impaired it will do nothing, and that is knowable in advance.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Nightly, 3–6 month courses
Typical compounding-clinic practice, longer than the community cycling patterns used for research-chemical secretagogues.
Not part of either documented protocol
Neither the Gold Standard Protocol nor the 15-Compound Matrix names it — both use tesamorelin or CJC-1295 for the GHRH arm.
05b Condition-specific interest
Sermorelin has the most legitimate clinical history of the secretagogues in this library and the shortest duration of action — and those two facts are related. It is GHRH(1–29), the native hormone truncated to its active fragment, and it does not try to be anything more than that.
No approval, no trial
Sermorelin was historically licensed as a diagnostic agent and for paediatric growth hormone deficiency; that product has been withdrawn from the US market. What circulates now is compounded or research-grade material, and no controlled human trial supports any of the adult anti-ageing uses below.
Study — historical, and mostly paediatric
Growth hormone deficiency — where it came from
Pathophysiology
GH deficiency in children produces growth failure. In adults it follows pituitary disease, surgery, radiotherapy or trauma, and is diagnosed on a provocative stimulation test.
Mechanistic rationale
Sermorelin was used both to test whether a pituitary could respond to GHRH and to treat paediatric GH deficiency where the pituitary was intact. That is a genuine clinical history and it is why this compound sits differently from the rest of the section. It also defines the limit: a secretagogue needs a working pituitary, so in true adult GH deficiency — where the pituitary is the lesion — recombinant GH is the treatment and this is not.
Community reports
Prescribed by wellness and anti-ageing clinics for adult use, which is not the indication it held.
Components carrying the argument: GHRH(1–29) — the native signal, truncated
Theorized — the most physiological case in the section
The ageing GH axis — and why short action is the argument
Pathophysiology
GH secretion declines with age, and the decline is in pulse amplitude rather than in the capacity of the pituitary to respond. The axis becomes quieter, not broken.
Mechanistic rationale
Sermorelin has a very short half-life — minutes — so it produces a pulse and then gets out of the way, leaving somatostatin feedback and the natural rhythm intact. That is the strongest theoretical argument any compound in this section has, because the pathological state of this axis (acromegaly) is defined by continuous elevation rather than by large pulses. It is also why sermorelin produces less dramatic effects than the longer-acting analogues, which is a feature rather than a shortfall.
Community reports
Users describe it as gentler and less prone to fluid retention and carpal tunnel symptoms than DAC-modified analogues — consistent with shorter exposure.
Components carrying the argument: Preserved pulsatility and feedback
Theorized — shared with the whole axis
Sleep, body composition and the rest of the claim set
Pathophysiology
Deep sleep, lean mass, visceral fat and bone turnover are all GH-responsive to some degree.
Mechanistic rationale
Every claim made for the Ipamorelin + CJC-1295 stack applies here in weaker form, and the caveats apply in full: sleep drives GH rather than the reverse; lean mass and function separate; GH is diabetogenic; and thyroid labs can move without thyroid function changing. Those are covered in detail on the blend page and are not repeated here.
Community reports
Deeper sleep is the most consistently reported effect, as across this class, and is among the most placebo-susceptible endpoints in this library.
Components carrying the argument: Downstream GH and IGF-1
Actionable context
The direction of travel
Pathophysiology
Chronic GH excess causes cardiomyopathy, hypertension, sleep apnoea, insulin resistance, arthropathy and increased colorectal neoplasia.
Mechanistic rationale
Sermorelin is the least likely compound in this section to push the axis anywhere near that, because it does not sustain exposure. It is still pushing in the same direction, and octreotide — the drug prescribed to suppress this hormone in acromegaly — is worth reading alongside it.
Community reports
Rarely raised.
Components carrying the argument: The axis itself
| Question | Position |
|---|---|
| Historical approval? | Yes — diagnostic and paediatric GHD; withdrawn from the US market |
| Adult anti-ageing use? | Off-label, unlicensed, no controlled trial |
| Half-life | Minutes — the shortest in the section |
| Why that matters | Pulse preserved, somatostatin feedback intact |
| Works in true adult GHD? | Poorly — the pituitary is the lesion |
| Shared GH liabilities | Glucose, fluid retention, thyroid labs — see the blend page |
What actually has evidence for these conditions
For diagnosed GH deficiency: recombinant human GH under endocrinology supervision, after a provocative test.
For the age-related decline: resistance training and adequate protein have the evidence and improve function rather than only mass. Deep sleep is when the largest natural GH pulses occur, so treating insomnia and screening for obstructive sleep apnoea are upstream of anything a secretagogue can do — a compound cannot substitute for the sleep it depends on.
06 Handling, reconstitution & storage
Physical-chemistry reference for laboratory handling of the lyophilised material. Reproduced so that stability and concentration mathematics can be studied — see the calculator for the arithmetic and the reconstitution guide for sterile technique.
Reconstitution
Supplied lyophilised, commonly 10 mg per vial in the research market, or compounded to a specified concentration by a pharmacy. At 300 mcg nightly a 10 mg vial is about a month.
Storage
Lyophilised: refrigerated or frozen. Reconstituted: 2–8 °C.
Common vial sizes
Commonly 10 mg lyophilised vials; compounded preparations vary.
Stability notes
The unmodified native sequence is more susceptible to enzymatic degradation in vivo than the engineered analogues — this affects duration of action rather than vial stability.
07 Legal & regulatory status
Regulatory status changes and differs by country. This is a summary for orientation, not legal advice — check your own jurisdiction.
Formerly FDA-approved as Geref; withdrawn from the US market for commercial reasons. That withdrawal did not reflect a safety finding, and sermorelin remains the most widely compounded GH secretagogue in the United States, dispensed through licensed compounding pharmacies on prescription.
Material sold as research-grade sermorelin is a different supply route from a compounded prescription and carries none of the same controls.
Regulatory and trial claims re-checked against primary sources on 16 August 2026. Checked: Geref withdrawn 2008; exists only as compounded, no FDA-approved product. Approvals, trial readouts and compounding decisions move faster than anything else on this page — a date here means someone looked, not that nothing has changed since.
Anti-doping
GHRH analogues are explicitly named on the WADA Prohibited List under S2. Prohibited at all times.
§ Sources & further reading
Links resolve to PubMed records, trial registries, publisher pages or primary documents. Where a body of work rather than a single paper is cited, the link opens a PubMed query so the full result set — including newer papers than this page — can be reviewed. Verify every claim against the primary source before relying on it.
- PubMed: sermorelin / GHRH(1-29) — clinical use, diagnostic testing and regulatory history (live query)Database or literature search
- PubMed: GHRH analogues and GH secretagogue co-administration in adults (live query)Database or literature search
- PubMed: growth hormone excess — insulin resistance, oedema, arthralgia (live query)Database or literature search
Reminder
For educational and research reference only. Nothing on this site is medical advice, a recommendation, or an instruction to administer any substance to a human being. Every figure on this page is a record of what has been reported, not a recommendation. Full disclaimer.