Sermorelin + GHRP Blend
The legacy GH-axis pairing that predates the clean ipamorelin stacks, combining a GHRH analog with a non-selective ghrelin-receptor agonist to amplify the growth hormone pulse.
Sermorelin + GHRP-2 is a two-peptide blend that hits both arms of growth hormone release at once: sermorelin (the GHRH 1-29 analog) supplies the GHRH-receptor signal on pituitary somatotrophs, while GHRP-2 supplies the ghrelin-receptor signal. Together they produce more GH than either compound alone, a synergy that is among the better-documented effects in this category. It is the older version of the same two-receptor logic later rebuilt with ipamorelin, whose selectivity is why most peptide clinics migrated off GHRP-2.
Class
GHRH analog + GHRP (growth hormone secretagogue) blend
Half-life
Sermorelin ~6 min (IV); GHRP-2 ~15-60 min
Routes
Subcutaneous injection
Category
Growth Hormone & Performance
Researched benefits
What it's studied for
Synergistic growth hormone release
Combining a GHRH analog with a GHRP amplifies GH output through two receptor pathways at once. In healthy adults, GHRH plus GHRP-6 produced GH roughly triple either compound alone (Pombo 1995), and GHRP-2 plus GHRH showed acute supra-additive synergy with GHRH in controlled work (Bowers 2004). This dual-receptor synergy is the strongest, best-documented part of the blend's case.
Sustained IGF-1 elevation
A 30-day study of GHRP-2 with GHRH showed sustained GH and IGF-1 elevation and ongoing GH-axis activation (Bowers 2004). Downstream IGF-1 is what the recovery and body-composition interest tracks.
Robust, low-cost secretagogue response
GHRP-2 is one of the cheaper secretagogues on the research-peptide market and produces a robust GH response, while sermorelin brings the only FDA-approval pedigree in the GHRH class. Both halves are individually well-studied, which is unusual for a blend.
Appetite stimulation for bulking
The GHRP-2 half increases appetite via ghrelin-receptor pharmacology; subcutaneous GHRP-2 increased food intake by about 36% in healthy men (Laferrere 2005). For users specifically chasing appetite during a bulk, this hunger is treated as a feature rather than a side effect.
Mechanism
How it works
The blend hits both arms of growth hormone release simultaneously. Sermorelin, a GHRH analog corresponding to the 1-29 fragment of growth hormone-releasing hormone, triggers GH release from pituitary somatotrophs via the GHRH receptor. GHRP-2, a synthetic non-selective ghrelin-receptor agonist, amplifies the same GH pulse through the ghrelin (GHS) receptor. Because the two peptides act on distinct receptors, their combined effect is supra-additive: together they release substantially more GH than either arm alone.
This GHRH-plus-GHRP synergy is one of the better-documented effects in the growth hormone secretagogue category. Combined dosing produced GH roughly triple either compound alone in healthy adults (Pombo 1995 with GHRP-6), and GHRP-2 with GHRH showed both acute supra-additive synergy and sustained 30-day axis activation (Bowers 2004). The magnitude of the synergy is dosing-dependent, and one single-bolus study could not fully separate GHRP-2 + GHRH synergy from simple additivity because GHRP-2's own potency masked the GHRH contribution (Tiulpakov 1995).
The weak link is the GHRP-2 leg rather than the mechanism. The same ghrelin-receptor activity that drives GH also raises cortisol, prolactin, and appetite: GHRP-2 is not fully selective and raised prolactin, ACTH, and cortisol in human subjects (Arvat 1997). This is precisely the pharmacology that newer stacks engineered out by substituting ipamorelin, a selective GHRP that releases GH without moving cortisol, prolactin, or ACTH (Raun 1998).
Dosing protocols
Dosing & administration
Dosing reflects protocols reported in research and community literature for educational purposes. It is not medical advice or a recommendation. Most peptides here are not approved for human use.
Reconstitution
Supplied as two peptides in one vial or reconstituted together. No FDA-approved dosing framework exists for either component in this context or for the blend; reconstitution and concentration are formulation- and source-specific.
Community practice
- Dose
- Source- and clinic-specific; not established by any label
- Frequency
- Older protocols used multiple small daily injections
- Timing
- Typically timed to leverage pulsatile GH release
- Duration
- Variable
- Route
- Subcutaneous injection
The GHRP-2 half's short half-life (~15-60 min) is the reason legacy protocols used several small daily doses rather than a single injection. There is no fixed-dose RCT of this specific blend; all schedules are practice patterns, not label instructions.
- There is no FDA-approved dosing framework for either component in this context or for the blend, and there are zero RCTs of this fixed blend specifically.
- The GHRP-2 half's short half-life is why older protocols used multiple small daily injections.
- Sermorelin (3357.9 Da) and GHRP-2 (817.97 Da) differ roughly four-fold in mass and degrade at different rates in reconstituted solution, so any labeled component ratio's durability is source-specific rather than independently established.
- Compounded sermorelin access has tightened as the FDA worked through its 503A bulk-substance review of compounding peptides.
Evidence
Research & clinical studies (6)
GHRH plus GHRP-6 combined dosing in healthy adults (Pombo)
In healthy adults, GHRH combined with GHRP-6 produced GH roughly triple that of either compound administered alone, establishing the dual-receptor synergy.
30-day GHRP-2 plus GHRH axis activation study (Bowers)
GHRP-2 with GHRH produced sustained GH and IGF-1 elevation over 30 days plus acute supra-additive synergy that varied by age and sex.
Single-bolus GHRP-2 plus GHRH synergy assessment (Tiulpakov)
A single-bolus study could not separate GHRP-2 + GHRH synergy from simple additivity because GHRP-2's own potency masked the GHRH contribution.
GHRP-2 selectivity and hormonal profile in humans (Arvat)
GHRP-2 is not fully selective, raising prolactin, ACTH, and cortisol alongside GH in human subjects.
Subcutaneous GHRP-2 and food intake in healthy men (Laferrere)
Subcutaneous GHRP-2 increased food intake by about 36% in healthy men, consistent with ghrelin-receptor pharmacology.
Ipamorelin selectivity characterization (Raun)
Ipamorelin releases GH without moving cortisol, prolactin, or ACTH, defining the selectivity gap that moved standard stacks off GHRP-2.
Combinations
Stacking & blends
Sermorelin + GHRP-2 (this blend)
Amplified pulsatile GH release plus appetite support
Sermorelin supplies the GHRH-receptor signal and GHRP-2 supplies the ghrelin-receptor signal, hitting both arms of GH release at once for documented synergy; the GHRP-2 leg additionally drives appetite, treated as a feature during a bulk.
CJC-1295 + Ipamorelin (modern equivalent)
Same two-receptor GH synergy with a cleaner hormonal profile
The modern rebuild of the same GHRH-plus-GHRP logic, substituting selective ipamorelin for GHRP-2 to deliver the same core GH signal without raising cortisol, prolactin, or appetite.
Safety
Side effects & considerations
Commonly reported effects
Contraindications & cautions
- Competitive athletes subject to WADA (both components are prohibited, Section S2)
- Individuals seeking to avoid cortisol/prolactin elevation should consider a selective alternative such as ipamorelin
The sermorelin half is generally mild (transient flushing, injection-site reactions, occasional headache). The GHRP-2 half is where the profile widens: alongside GH it raises cortisol, prolactin, and appetite, documented in human studies (Arvat 1997, Laferrere 2005). The cleaner-profile reason modern stacks swapped GHRP-2 for ipamorelin is exactly this.
FAQ
Sermorelin + GHRP Blend — common questions
What is the sermorelin + GHRP-2 blend?
A combination of two growth hormone-stimulating peptides in a single vial: sermorelin (a GHRH analog, the 1-29 fragment of human growth hormone-releasing hormone) and GHRP-2 (a synthetic ghrelin-receptor agonist). It hits both arms of GH release, the GHRH side and the GHRP side, for synergistic pulsatile GH stimulation. It is the legacy version of the pairing that newer stacks rebuilt with ipamorelin in place of GHRP-2.
What does the blend do?
It stimulates pulsatile growth hormone release through two complementary receptors. Sermorelin triggers GH release from pituitary somatotrophs via the GHRH receptor; GHRP-2 amplifies the pulse via the ghrelin receptor. The synergy is documented: combined GHRH-plus-GHRP dosing produces substantially more GH than either alone. Downstream IGF-1 rises, which is what the recovery and body-composition interest tracks.
How is it typically administered?
Research and clinic formulations vary, and there is no FDA-approved dosing framework for either component in this context or for the blend. Community route and schedule claims are practice patterns, not label instructions. The GHRP-2 half's short half-life is the reason older protocols used multiple small daily injections.
What are the side effects?
The sermorelin half is generally mild: transient flushing, injection-site reactions, occasional headache. The GHRP-2 half is where the profile widens. Alongside GH release it raises cortisol, prolactin, and appetite, documented in human studies. Increased hunger and occasional fluid retention are commonly reported. The reason modern stacks swapped GHRP-2 for ipamorelin is exactly this cleaner-profile difference.
Is the blend FDA approved?
No. Sermorelin was FDA-approved as Geref for pediatric growth hormone deficiency in 1997 and withdrawn in 2008 for commercial reasons, but it has no current FDA-approved product and was never approved for adult GH-axis use. GHRP-2 was never FDA-approved. The blend itself has no approved use. Both are prohibited under WADA for competitive athletes.
How does it compare to CJC-1295 + ipamorelin?
Same two-receptor logic, older parts. Both stacks hit the GHRH receptor and the ghrelin receptor at once to amplify the GH pulse. The difference is the secretagogue half: ipamorelin is selective and releases GH without moving cortisol, prolactin, or ACTH (Raun 1998), whereas GHRP-2 releases GH at least as strongly but also raises cortisol, prolactin, and appetite (Arvat 1997). That selectivity gap is the entire reason peptide clinics migrated off this pairing.
Is the synergy real?
Yes. The GHRH-plus-GHRP synergy is one of the better-documented effects in this whole category. With GHRP-6, combined dosing produced GH roughly triple either compound alone (Pombo 1995), and with GHRP-2 a 30-day study showed sustained GH and IGF-1 elevation with acute supra-additive synergy (Bowers 2004). One single-bolus study could not separate synergy from simple additivity because GHRP-2 is potent enough on its own to mask the GHRH contribution (Tiulpakov 1995).
