Boost is a prescription medication used to treat erectile dysfunction and/or sexual performance anxiety. It combines 8 mg of tadalafil with 50 mg of DHEA. Tadalafil (the active ingredient in Cialis®) is a PDE5 inhibitor that works by dilating blood vessels and increasing blood flow to the penis, making it easier to achieve and maintain an erection. DHEA is a supplement that has been shown to convert into testosterone in the body and is added for support. Effects can last up to 36 hours.