Editor,—Testosterone undecanoate, an orally active androgen, has been in clinical use for about 20 years.1Its efficacy for the acceleration of growth has been well documented in prepubertal and early pubertal boys.2 3 We wondered if it could be used for the induction of puberty in anorchia as preliminary data suggested.4

Ten anorchid patients (bilateral neonatal testicular torsion in three, congenital anorchia in seven) were treated with testosterone undecanoate. Four boys received 40 mg three times weekly. This dose was felt to be insufficient. Six boys aged 11–14 years (mean 12.0 years) received 40 mg daily for 12.5 months (range 5–20) and then 80 mg daily for another 10.2 months (range 6–15). In these six boys, pubic hair Tanner stage 2 was observed after 5.8 months (range 5–8) and Tanner stage 3 after 15.5 months (range 12–20). The time interval of 10 months for progression of pubic hair stage 2 to stage 3 is comparable with the finding in normal boys. In their longitudinal study, Largo and Prader observed that in 52% of the boys pubic hair progressed from stage 2 to stage 3 within one year.5 In the first year of treatment, height velocity was 7.2 cm/year (6.0–9.0) and weight gain was 7.0 kg (5.2–8.0). Stretched penile length increased from 3.5 cm (3.0–4.0) before to 6.2 cm (5.0–8.0) at the end of treatment.

We conclude that oral testosterone undecanoate treatment in anorchid boys is simple, safe, and effective. Starting at the age of 11 to 12 years with a dose of 40 mg daily for one year and 80 mg daily for another year provides for a gentle induction of puberty with normal tempo. Life long testosterone substitution must then be continued by the intramuscular or potentially by the transdermal route.