A study in 2013 published in Nutrition Research found that after 28 days of D-AA supplementation there was no significant increase in testosterone levels.
All reports about testosterone boosters being able to help increase motivation seems unfounded and lacking in authenticity. This mantra even applies to testosterone boosters used to rev up men’s sex drives. Annual sales of prescription hormone enhancers have more than doubled since 2008, according to research, and some experts predict it will be a $5 billion industry by 2017.