GHRP-2 dosing & administration

Norman C et al. · 2013

Testosterone and estradiol positively determine GH responses to GHRP-2 in older men, while BMI negatively affects pulsatile GH secretion during GHRP-2 infusion.

Veldhuis JD et al. · 2009

GHRP-2 was more stimulatory than GHRH for GH release in women. Age and estrogen status together explained 60% of the variability in GHRP-2 effectiveness.

Veldhuis JD et al. · 2009

L-arginine combined with GHRP-2 provides a robust GH stimulus that remains effective even during short-term hormone deficiency, unaffected by visceral fat or IGF-1 levels.

Veldhuis JD et al. · 2009

Abdominal visceral fat is a dominant negative predictor of both GHRH and GHRP-2 effectiveness. Fasting IGF-I concentration positively correlates with secretagogue efficacy.

Mericq V, Cassorla F, Salazar T, Avila A, Iniguez G, Bowers CY, Merriam GR · 1998

The only chronic human study of GHRP-2, and it is small. Six prepubertal children with growth hormone deficiency received escalating subcutaneous doses of 0.3, then 1.0, then 3.0 mcg/kg per day, each for a 2-month period, followed by a fourth period combining 3 mcg/kg GHRP-2 with 3 mcg/kg GHRH. Overnight GH secretion rose dose-wise and growth velocity was higher during treatment than before or after. But serum IGF-I and IGFBP-3 DID NOT INCREASE, and the GH profiles showed the effect of each injection was brief with little influence on secretion later in the night. No side effects or toxicities were observed in those 6 children. The authors' own conclusion is that formulations with a longer duration of action would be needed for GHRP-2 to be useful as therapy.

Kaken Pharmaceutical Co., Ltd.; Pharmaceuticals and Medical Devices Agency (PMDA), Japan · 2025

The only regulatory approval this compound has anywhere, and it is for a diagnostic test rather than a treatment. The approved indication is the diagnosis of growth hormone deficiency (成長ホルモン分泌不全症の診断). The dose is a SINGLE slow intravenous injection given fasted, after dissolving the vial in 10 mL of saline: 100 μg for anyone aged 18 or over, and 2 μg per kg of body weight for ages 4 to under 18, capped at 100 μg for children over 50 kg. Adverse reactions listed on the label are abdominal rumbling, leukocytosis, a feeling of warmth, low blood pressure, nausea, gastric discomfort, abdominal distension, drowsiness and a runny nose. Nothing on this label covers repeated dosing, subcutaneous injection, or use for body composition.

Laferrère B, Hart AB, Bowers CY · 2006

The clearest measurement of what GHRP-2 does to appetite in people. Nineteen healthy weight-stable adults (10 lean, 9 obese) each received, double-blind and in random order, a subcutaneous infusion of GHRP-2 at 1 mcg/kg/hour, 0.1 mcg/kg/hour, or placebo over 270 minutes, then ate freely at a buffet lunch. Food intake rose 10.2 ± 3.9% at the low rate (p=0.011) and 33.5 ± 5.8% at the high rate (p<0.001) against placebo, dose-dependently. Obesity did not blunt the effect — obese participants responded as much as lean ones, in both food intake and GH. Appetite ratings before the meal were higher while fullness afterwards was the same, so the drive is to start eating rather than to stop later.

Van den Berghe G, Baxter RC, Weekers F, et al. · 2002

Thirty-three critically ill men were randomised to 5 days of placebo (n=7), GHRP-2 alone at 1 mcg/kg/hour (n=9), GHRP-2 plus TRH (n=9), or GHRP-2 plus TRH plus pulsatile GnRH (n=8). GHRP-2 alone reactivated GH secretion and normalised IGF-I, IGFBP-3 and the acid-labile subunit. It did not deliver the metabolic benefit: ureagenesis fell with the two combinations (p=0.01 and p=0.009) but NOT with GHRP-2 alone, and osteocalcin rose only with the triple combination. By day 5, serum lactate and white cell count were increased by GHRP-2 infused alone and with TRH, but not by the triple combination. Restoring one hormonal axis in isolation was not enough, and carried signals the fuller replacement did not.