Starting a short cycle of Tribulus. According to recent scientific work, it may lead to improvements if taking at least 1,500 mg a day for 10 days. No benefits after that. My first time trying it, will see what happens.
The influence of the Tribulus terrestris extract o... [Fiziol Zh. 2009] - PubMed result
but also see here for contradictory results:
Effects of anabolic precursors on serum testostero... [Int J Sport Nutr Exerc Metab. 2000] - PubMed result