Efficacy and Safety of 5-Aminolevulinic Acid for Patients with Symptoms of Late-Onset Hypogonadism: A Preliminary Study

Purpose: As the concept of late-onset hypogonadism (LOH) has gained increased attention, the treatment of eugonadal patients with LOH symptom has become a clinical problem. Previous studies have shown the possible benefits of 5-aminolevulinic acid (5-ALA) on the somatic, psychological and sexual functions. We therefore conducted this randomized, double‑blind, placebo‑controlled study to confirm the efficacy and safety of 5-ALA for LOH symptoms. Materials and Methods: Thirty-two eugonadal subjects with LOH symptoms were randomly divided into a 5-ALA group (n=15) and a placebo group (n=17). Treatment was continued for 8 weeks. The change of the Aging Males’ Symptoms (AMS) scale score and several biochemical and endocrinological variables during treatment were compared between the groups. Results: After treatment, the change in the total AMS in the 5-ALA group was significantly greater than that in the placebo group (-7.4±4.7 vs. -4.9±4.9, p=0.029). However, the differences between the groups in the change of the somatic, psychological, and sexual sub-scores of the AMS did not reach the statistical significance, although these changes in the 5-ALA group were greater than those in the placebo group. Furthermore, the change in the biochemical and endocrinological variables in the two groups did not differ to a statistically significant extent. During the 8-week treatment period, no patients discontinued 5-ALA due to treatment-emergent adverse events (TEAEs). Conclusions: The intake of 5-ALA for 8 weeks was beneficial for eugonadal patients with symptoms of LOH and no severe TEAEs was experienced. 5-ALA should be considered as an option for those patients.