Growth Hormone Peptide Dosage Protocols
Growth hormone secretagogues stimulate the pituitary to release endogenous GH. The category covers CJC-1295, Ipamorelin, Sermorelin, Tesamorelin, GHRP-2, GHRP-6, and downstream IGF-1 derivatives.
15 protocols indexed
Tesamorelin
Tesamorelin (trade name Egrifta) is a synthetic 44-amino-acid analogue of human growth hormone-releasing hormone (GHRH) stabilised by an N-terminal trans-3-hexenoyl modification that resists DPP-IV cleavage. It is the only GHRH-class peptide with full FDA approval, granted in November 2010 for the reduction of excess visceral adipose tissue in HIV-infected adults with lipodystrophy. The landmark 26-week Phase III trial by Falutz and colleagues (NEJM 2007) demonstrated a 15.2% reduction in visceral adipose tissue versus a 5% increase on placebo with 2 mg subcutaneous daily dosing, while Stanley and colleagues (JAMA 2014, Lancet HIV 2019) extended these findings to hepatic steatosis, showing a 37% relative reduction in liver fat fraction. Because tesamorelin acts upstream on the pituitary somatotroph rather than replacing growth hormone directly, it preserves the pulsatile GH rhythm and operates within physiologic IGF-1 feedback. Outside the HIV indication it remains investigational, and use in healthy adults for cosmetic body recomposition is off-label.
Open Protocolarrow_forwardGH Secretagogue / GrowthCJC-1295 NO DAC
CJC-1295 without DAC, more accurately called Modified GRF(1-29) or Mod GRF 1-29, is a 30-amino-acid analogue of human growth hormone-releasing hormone consisting of GRF(1-29) with four targeted amino-acid substitutions (D-Ala2, Gln8, Ala15, Leu27) that stabilise the molecule against dipeptidyl peptidase-IV degradation but do not include the maleimido-propionic acid Drug Affinity Complex (DAC) linker. The result is a short-acting GHRH analogue with a plasma half-life of approximately 30 minutes that produces a sharp, physiologic GH pulse and clears quickly enough to preserve negative-feedback dynamics. It has no FDA-approved indication and is supplied strictly as a research chemical. Typical research dosing is 100 mcg subcutaneously two to three times per day, often combined with a selective ghrelin-receptor agonist such as ipamorelin. The compound is the workhorse short-acting GHRH analogue in the peptide research community because it mimics endogenous GHRH kinetics more closely than the DAC-bound version and avoids the continuous-stimulation problem.
Open Protocolarrow_forwardGH Secretagogue / GrowthCJC-1295 DAC
CJC-1295 with DAC is a 30-amino-acid analogue of GRF(1-29) covalently conjugated through a maleimido-propionic acid linker (the Drug Affinity Complex) to circulating serum albumin. The albumin tether shields the peptide from renal filtration and proteolysis, extending plasma half-life from minutes to 6 to 8 days as established in the Teichman et al. JCEM 2006 Phase I trial. Single subcutaneous injection of 60 to 90 mcg/kg produced mean growth hormone elevations of two- to ten-fold and IGF-1 elevations of 1.5 to 3-fold persisting for 9 to 11 days in 21 healthy adult subjects. The compound is not FDA approved for any indication; original developer ConjuChem suspended Phase II development in 2007 after sudden cardiac deaths in a separate combination trial, and no further regulatory progress has occurred. Typical research dosing is 1 to 2 mg subcutaneously once per week. Because the molecule produces continuous low-amplitude GH elevation rather than discrete pulses, its pharmacology diverges meaningfully from native GHRH and short-acting analogues such as Mod GRF 1-29 or tesamorelin.
Open Protocolarrow_forwardGH Secretagogue / GrowthGHRP-2
GHRP-2 (pralmorelin, D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2) is a synthetic hexapeptide growth hormone secretagogue and full agonist at the growth hormone secretagogue receptor type 1a (GHSR1a), the same receptor that endogenous ghrelin engages. Originally described by Bowers and colleagues in the early 1990s, GHRP-2 stimulates pituitary GH release through ghrelin-receptor activation in the somatotroph and simultaneous suppression of somatostatin tone in the hypothalamus, producing a sharp dose-dependent GH pulse with a half-life of approximately 15 to 60 minutes. It is approved as a diagnostic provocative test for childhood GH deficiency in Japan under the name pralmorelin hydrochloride, but it has no FDA-approved therapeutic indication in the United States. Typical research dosing is 100 to 300 mcg subcutaneously two to three times per day. GHRP-2 is more potent than GHRP-6 on a per-microgram basis (Bowers 1998) but is less receptor-selective than ipamorelin, producing measurable rises in prolactin and cortisol at higher doses.
Open Protocolarrow_forwardGH Secretagogue / GrowthGHRP-6
GHRP-6 (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) is a synthetic hexapeptide growth hormone secretagogue and the first non-natural GHSR1a agonist with documented potent appetite-stimulating activity. It binds the ghrelin receptor in the pituitary and arcuate nucleus, producing dose-dependent growth hormone release and the most pronounced orexigenic effect of any GHRP through neuropeptide Y and agouti-related peptide neuron activation in the hypothalamus. Bowers and colleagues first characterised it in 1984 and Smith et al. detailed the receptor pharmacology in the landmark Endocrine Reviews 1997 paper that helped lead to ghrelin's identification three years later. GHRP-6 has no FDA-approved indication and remains a research chemical. Typical research dosing is 100 mcg subcutaneously two to three times per day, often paired with a GHRH analogue. The combination of measurable appetite stimulation, dose-dependent GH release of 5-15 fold above baseline, and lower per-microgram potency than GHRP-2 makes GHRP-6 the GHRP of choice in research contexts focused on cachexia, sarcopenia and conditions where appetite restoration is desirable.
Open Protocolarrow_forwardResearch PeptideHGH 191AA
HGH 191AA, more accurately named somatropin, is recombinant human growth hormone produced by E. coli or mammalian expression systems and structurally identical to the 191-amino-acid pituitary-derived hormone. It is the only fully FDA-approved growth hormone replacement product and is licensed for adult and paediatric growth hormone deficiency, Turner syndrome, Prader-Willi syndrome, idiopathic short stature, chronic kidney disease and HIV wasting under brand names including Genotropin, Humatrope, Norditropin, Saizen, Omnitrope and Nutropin. The Molitch et al. Endocrine Society Clinical Practice Guideline (JCEM 2011) established adult dosing at 0.15 to 0.3 mg subcutaneously once daily, titrated against IGF-1 in the mid-normal age- and sex-adjusted range, typically to 0.4 to 0.6 mg/day in younger adults and 0.2 to 0.4 mg/day in patients above 60 years. Unlike GHRH analogues and GHRPs, somatropin replaces growth hormone directly rather than stimulating endogenous release; this bypasses pituitary feedback and produces continuous low-level GH exposure rather than physiologic pulses, which is the primary pharmacological trade-off with this drug class.
Open Protocolarrow_forwardGH Secretagogue / GrowthIpamorelin
Ipamorelin (Aib-His-D-2-Nal-D-Phe-Lys-NH2) is a synthetic pentapeptide growth hormone secretagogue and a highly selective full agonist at the growth hormone secretagogue receptor type 1a (GHSR1a). Developed by Novo Nordisk in the late 1990s and described in the landmark Raun et al. European Journal of Endocrinology 1998 paper, ipamorelin produced dose-dependent growth hormone release with no measurable elevation in ACTH, cortisol or prolactin even at doses exceeding 200-fold the ED50 for GH release. This unique receptor selectivity distinguishes ipamorelin from earlier GHRPs (GHRP-2, GHRP-6, hexarelin), which all engage non-GHSR1a pathways that drive HPA-axis and prolactin responses. Ipamorelin has no FDA-approved indication; Novo Nordisk discontinued clinical development in 2007 after a Phase II trial in postoperative ileus failed to show efficacy. It remains the most widely used GHRP in research peptide protocols, typically dosed at 100 to 300 mcg subcutaneously two to three times per day and almost always stacked with a GHRH analogue such as CJC-1295 no DAC, sermorelin or tesamorelin to exploit the GHRH/GHRP synergy at the somatotroph.
Open Protocolarrow_forwardResearch PeptideIGF-1 LR3
IGF-1 LR3 (Long-Arg3-IGF-1) is an 83-amino-acid recombinant analogue of insulin-like growth factor-1 with two engineered modifications: an arginine substitution at position 3 and a 13-amino-acid N-terminal extension derived from methionyl-porcine GH. These modifications reduce binding to insulin-like growth factor binding proteins (IGFBPs) by approximately 1000-fold while preserving full agonist activity at the IGF-1 receptor. The result is a research compound with an effective half-life of 20 to 30 hours in plasma compared with 12 to 15 minutes for native IGF-1, making IGF-1 LR3 the standard tool for studying IGF-1 receptor signalling in cell culture and in vivo models. It has no FDA approval and is supplied strictly as a research chemical. Typical research dosing is 20 to 80 mcg subcutaneously per day. Unlike GHRH analogues and GHRPs, which stimulate endogenous pituitary GH release and engage the natural feedback loop, IGF-1 LR3 bypasses both the pituitary and the GH receptor entirely and engages the IGF-1R directly, which produces a distinct pharmacology including direct hypoglycaemic risk from IGF-1R cross-talk with the insulin receptor.
Open Protocolarrow_forwardResearch PeptideMGF
MGF (Mechano Growth Factor), more precisely IGF-1Ec, is a splice variant of the IGF-1 gene transcript that produces a precursor protein containing the mature IGF-1 sequence linked to a distinctive 24-amino-acid carboxy-terminal E-domain peptide. Goldspink and colleagues (FEBS Letters 2002, J Physiol 2003) characterised the splice event in skeletal muscle as the immediate response to mechanical overload or injury, with IGF-1Ec transcription preceding the conventional IGF-1Ea isoform by several hours. The cleaved E-peptide (the MGF peptide proper) appears to act independently of mature IGF-1 to activate quiescent satellite cells, drive myoblast proliferation, and delay differentiation, allowing the muscle stem-cell pool to expand before fusion into repaired fibres. MGF has no FDA approval and is supplied strictly as a research chemical. Typical research dosing is 100 to 200 mcg locally intramuscular post-workout. Native MGF E-peptide has a plasma half-life of approximately 5-7 minutes, which is why local rather than systemic injection is the standard research administration; the PEGylated variant (PEG-MGF) addresses this through pegylation.
Open Protocolarrow_forwardResearch PeptidePEG MGF
PEG-MGF (pegylated Mechano Growth Factor) is a synthetic 24-amino-acid analogue of the IGF-1Ec E-domain peptide modified by covalent attachment of polyethylene glycol chains to extend plasma half-life. Native MGF has a half-life of 5-7 minutes due to rapid proteolytic degradation; pegylation extends this to approximately 24-48 hours by shielding proteolytic recognition sites and reducing renal filtration. The structural premise is to deliver the satellite-cell-activating signal systemically rather than purely locally, addressing the principal pharmacological limitation of native MGF. PEG-MGF has no FDA approval and is supplied strictly as a research chemical. Typical research dosing is 100 to 250 mcg subcutaneously two times per week. Like native MGF, PEG-MGF appears to act on a putative muscle-specific receptor rather than the canonical IGF-1R, so it does not produce hypoglycaemia or the systemic glucose-axis effects characteristic of IGF-1 LR3. The mechanistic case rests on the foundational Goldspink and Yang work characterising IGF-1Ec splice variants and the E-peptide's independent biological activity.
Open Protocolarrow_forwardGH Secretagogue / GrowthSermorelin
Sermorelin (formerly Geref) is a synthetic 29-amino-acid peptide consisting of the first 29 amino acids of human growth hormone-releasing hormone (GHRH) and was the first commercially marketed GHRH analogue. The biologically active region of native 44-amino-acid GHRH resides in the first 29 residues, making sermorelin a full agonist at the GHRH receptor. Sermorelin received FDA approval in 1990 as a diagnostic agent for GH deficiency and in 1997 for treatment of paediatric idiopathic GH deficiency under the brand name Geref (Serono). Serono voluntarily discontinued commercial production in 2008 due to manufacturing process difficulties, not safety concerns. The Geref International Study Group multicentre trial (J Pediatr 1996) showed that 30 mcg/kg/day subcutaneous sermorelin at bedtime increased growth velocity from 4.1 to 8.0 cm/year at 6 months in 110 GH-deficient prepubertal children. Although it no longer holds an active FDA-approved product, sermorelin is on the FDA 503A bulks list and remains widely used in compounding pharmacy. Adult research dosing is 200-500 mcg subcutaneously nightly.
Open Protocolarrow_forwardTherapeutic BlendCJC-1295 NO DAC + Ipamorelin
The CJC-1295 no DAC + ipamorelin stack is the most widely used growth hormone secretagogue combination in research peptide protocols. It pairs a short-acting GHRH analogue (Mod GRF 1-29, with a 30-minute half-life) and a highly selective GHSR1a agonist (ipamorelin, with a 2-hour half-life) to exploit the well-characterised synergy between the two pituitary somatotroph signalling pathways. The combination produces growth hormone responses 3 to 5 times higher than either agent administered alone, as demonstrated in multiple GHRH/GHRP synergy studies (Bowers JCEM 2001, Mericq JCEM 1998). Neither component is FDA approved; both are supplied solely as research chemicals. Typical research dosing is 100 mcg of each peptide subcutaneously two to three times per day, often co-injected from the same syringe pre-breakfast, mid-afternoon and pre-bed. The combination preserves pulsatile GH release, intact pituitary feedback regulation, and avoids the prolactin and cortisol elevations characteristic of GHRP-2 or GHRP-6, making it the preferred long-term stack for research-context body composition and recovery applications.
Open Protocolarrow_forwardTherapeutic BlendCJC-1295 + GHRP-2
The CJC-1295 + GHRP-2 stack combines a GHRH analogue with a potent ghrelin-receptor agonist to exploit the dual-pathway GH-release synergy at the pituitary somatotroph. Depending on the CJC-1295 variant used, the stack produces either pulsatile dual-pulse GH release (no-DAC variant) or continuous-plus-pulsed GH elevation (DAC variant). Bowers (JCEM 2001) and Mericq (JCEM 1998) established that combined GHRH + GHRP produces growth hormone responses 3 to 5 times higher than either agent alone, and GHRP-2 is approximately 2 to 3 times more potent per microgram than GHRP-6 at GHSR1a, making this stack one of the most aggressive GH-release combinations in research peptide use. Neither component is FDA approved; both are supplied solely as research chemicals. Typical research dosing is 100 mcg of CJC-1295 no DAC + 100-200 mcg GHRP-2 subcutaneously two to three times per day. The principal trade-off versus the ipamorelin variant is that GHRP-2 produces measurable prolactin and cortisol elevations at therapeutic doses, making it less favourable for long-term chronic dosing.
Open Protocolarrow_forwardTherapeutic BlendTesamorelin 5mg + Ipamorelin 5mg
The Tesamorelin + Ipamorelin stack pairs the only FDA-approved GHRH analogue (tesamorelin, approved for HIV lipodystrophy at 2 mg daily) with the most selective GHSR1a agonist (ipamorelin). The combination exploits the well-characterised GHRH/GHRP synergy at the pituitary somatotroph, where convergent Gs-cAMP and Gq-PLC signals produce GH responses 3-5 times higher than either agent alone (Bowers JCEM 2001). The stack is unusual within the GH secretagogue research space because the GHRH component carries actual FDA approval (for HIV lipodystrophy) while the GHRP component is supplied as a research chemical. Typical research dosing is 2 mg tesamorelin nightly + 100-300 mcg ipamorelin one to three times per day, with the bedtime injections co-administered. The 5 mg/5 mg vial nomenclature commonly used by research peptide suppliers refers to the total peptide content per reconstitution vial, not a single dose. The combination is particularly favoured in research contexts focused on visceral adipose tissue reduction because tesamorelin's documented VAT-selective lipolytic effect is amplified by the dual-pulse GH-release synergy.
Open Protocolarrow_forwardSynergistic StackCJC-1295 DAC + Ipamorelin
The CJC-1295 DAC + Ipamorelin stack combines a long-acting albumin-bound GHRH analogue (CJC-1295 DAC, half-life 6-8 days, weekly dosing) with a highly selective GHSR1a agonist (ipamorelin, half-life 2 hours, thrice-daily dosing). The pharmacology is distinct from the no-DAC variant of the stack: CJC-1295 DAC produces continuous low-amplitude GH elevation through its 6-8 day half-life, while ipamorelin adds discrete ghrelin-receptor-mediated GH pulses on top of the elevated baseline. Teichman et al. (JCEM 2006) characterised CJC-1295 DAC pharmacokinetics in 21 healthy adults, demonstrating GH elevations of 2-10 fold and IGF-1 elevations of 1.5-3 fold persisting 9-11 days after a single injection. Neither component is FDA approved; both are supplied solely as research chemicals. Typical research dosing is 2 mg CJC-1295 DAC subcutaneously weekly + 100-300 mcg ipamorelin two to three times per day. The stack offers weekly-dose convenience for the GHRH component but trades pulsatility for chronic receptor engagement, and carries the unresolved cardiac safety signal from CJC-1295 DAC's 2007 Phase II development pause.
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