Д-изомер аспарагиновой [[аминокислоты]], который естественным образом взаимодействует с определенными участками гипофиза, повышая секрецию тестостерона. Эффективность сомнительна.<ref>Darryn S. Willoughbyemail, Brian Leutholtz. d-Aspartic acid supplementation combined with 28 days of heavy resistance training has no effect on body composition, muscle strength, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained men. Received 6 June 2013; received in revised form 11 July 2013; accepted 13 July 2013. published online 19 August 2013.</ref>