Testosterone booster dietary supplement products claim to increase the male sex hormone testosterone, which affects muscle strength, endurance, and male sexual performance. There is insufficient evidence to support the claims for the many “natural ingredients” on the market. These ingredients include Tribulus terrestris , Eurycoma longifolia (Tongkat Ali or Longjack), Urtica dioica (stinging nettle), fenugreek, Mucuna pruriens (cowhage), D-aspartic acid, Bulbine natalensis , Saw palmetto, Epimedium grandiflorum (horny goat weed), diindolylmethane (DIM), maca, and a wide range of botanical extracts, plant steroids, and flavones.
As you get older, your testosterone levels go down, especially after you turn thirty. In fact, after the age of thirty, testosterone levels are shown to drop two to four percent per year! So if you find yourself being of a certain age, there’s a good chance that you have sub optimal levels. What Male Onyx proposes to do is provide you with more testosterone. Rather than pumping you full of chemical and synthetic ingredients that could have adverse effects on you, Male Onyx simply works to incorporate your body’s natural process. This is exactly why Male Onyx is at the top of it’s game. Because it believes that the best business model is quality.
Testosterone is significantly correlated with aggression and competitive behaviour and is directly facilitated by the latter. There are two theories on the role of testosterone in aggression and competition.  The first one is the challenge hypothesis which states that testosterone would increase during puberty thus facilitating reproductive and competitive behaviour which would include aggression.  Thus it is the challenge of competition among males of the species that facilitates aggression and violence.  Studies conducted have found direct correlation between testosterone and dominance especially among the most violent criminals in prison who had the highest testosterone levels.  The same research also found fathers (those outside competitive environments) had the lowest testosterone levels compared to other males.