GNRH1 and cartilage-hair hypoplasia: For optimal testicular growth and spermatogenesis, the individual dose of GnRH and the time required to achieve maximum effectiveness are variable, ranging from 25-600 ng/kg and requiring a minimum of two years [84]. According to Liu et al. [80], pulsatile sc GnRH therapy for two years in adolescents with the complete form of CHH does not significantly accelerate or enhance testicular growth, hasten the onset of sperm production, or increase sperm output compared to hCG/hMG therapy.