DHEAMay Have A Significant Impact On Lean Body Mass In one study conducted by D. Jakubowicz and colleagues, 22 men took 300 mg of DHEA nightly for 30 days. They observed an average 27% fall in insulin levels. They also found an 89% increase in IGF-1 (a powerful hormone with multi-faceted effects, most notable its growth hormone-like effects on body composition), a 14% decrease in body fat, and a 7.8% increase in lean body mass.DHEA May Block Cortisol