This randomised, double blind study involved 39 patients with Addison’s disease who were randomised to receive either 50mg oral dehydroepiandrosterone (DHEA) daily for 12 weeks followed by a 4-week washout period and then 12 weeks of placebo, or vice versa. Prior to receiving treatment, the patients with Addison’s disease had markedly subnormal DHEA-sulphate (DHEA-S) and DHEA levels. This study found that 50mg of DHEA corrected this deficiency, elevating the mean circulating DHEA-S level to 4.93 µmol/L. The rise in DHEA-S was also associated with the normalisation of its metabolite, Δ4-androstenedione and salivary levels of DHEA. In addition to its biochemical effectiveness in Addison’s disease, oral DHEA was well tolerated by the study participants and was associated with an improvement in psychological well-being, mood and fatigue.