Intranasal administration of the GHRP hexarelin accelerates growth in short children

Classic clinical work by the Zvi Laron group (Israel) — pediatric endocrinologist famous for describing GH insensitivity syndrome — exploring the potential of intranasal hexarelin as an oral-like therapy for short stature in childhood. The study is historically and mechanically important because it demonstrated that a short peptide can cross the nasal mucosa in sufficient quantity to produce a measurable clinical effect on longitudinal growth.

Eight prepubertal children (ages 4 to 11.6 years) with short stature were treated, receiving intranasal hexarelin 60 µg/kg three times daily for periods of up to 8 months. The design was open-label, with each child serving as its own control (pre-treatment versus during-treatment comparison). Outcomes included linear growth velocity, serum IGF-1, skinfold thickness, head circumference and biochemical markers of bone turnover.

Results were clinically relevant: growth velocity increased from 5.3 ± 0.8 to 8.3 ± 1.7 cm/year (p<0.0001) — a gain of approximately 60% on a key marker. Serum IGF-1 rose from 10.4 ± 3.9 to 14.1 ± 4.6 nmol/L, confirming activation of the GH-IGF-1 axis. There was also reduction in skinfold thickness, increase in head circumference and elevation of serum phosphate and alkaline phosphatase — all consistent with systemic anabolic effect. Adverse effects were minimal.

This work is frequently cited as proof-of-concept for the use of GHRPs in pediatrics, showing that the intranasal route — non-invasive and suitable for prolonged home use in children — is pharmacologically viable. Despite the positive result, hexarelin never reached regulatory approval for short stature, and pituitary desensitization with chronic use remains a concern. The study remains a seminal reference for the discussion of hexarelin in pediatric populations.