Side Effects
GHRP-2 is generally well-tolerated in clinical studies, with the intact somatostatin feedback loop providing a natural safety mechanism against GH overproduction.
Common (typically mild and transient):
- Increased appetite (moderate, less than GHRP-6)
- Flushing and warmth at the injection site or face
- Transient drowsiness or sleepiness, particularly with evening doses
- Mild water retention and peripheral edema
- Increased gastrointestinal motility
Less Common:
- Elevations in cortisol and ACTH (moderate, comparable to hCRH)
- Mild prolactin elevation (less than TRH-induced levels)
- Numbness or tingling in extremities
- Joint stiffness
- Lightheadedness post-injection
Rare or Theoretical Concerns:
- Impaired glucose metabolism and elevated blood glucose with prolonged use
- Potential tachyphylaxis (reduced response) with continuous daily dosing
- Theoretical promotion of existing malignancies through elevated GH/IGF-1 (applies to all GH-elevating compounds)
Side effect incidence tends to be lower than with exogenous hGH because GHRP-2 stimulates endogenous GH synthesis within physiological regulatory limits. The eight-month pediatric study by Mericq et al. reported no side effects or toxicities at any dose level tested.