Two hypothesized gender → testosterone pathways (our results supported the bolded pathway). Like humans, male cichlid fish who watch each other fight show increased testosterone (17). Testosterone responds to social phenomena that are evolutionarily salient, but not all social phenomena have been evolutionarily selected to modulate testosterone or do so in the same ways. A gender→testosterone pathway would involve multiple inputs including neurobiological, sociocultural, and evolutionary factors. Although testosterone exists and functions similarly in women and men, men have markedly higher average testosterone than women. Testosterone therapy is approved for the treatment of delayed male puberty and abnormally low production of testosterone secondary to malfunction of the testes, pituitary or hypothalamus. Women may have a testosterone deficiency due to diseases of the pituitary, hypothalamus or adrenal glands, in addition to removal of the ovaries. Although testosterone may make prostate cancer grow, it is not clear that testosterone treatment actually causes cancer. "Manosphere-driven health narratives can amplify fear, shame and distrust of mainstream healthcare. "When testosterone is sold as a shortcut to confidence and success, it’s doing more harm than good. "Promoting testing and treatment to men without clear medical indications raises concerns about overdiagnosis and overtreatment," added Dr Nickel. "Like many men, I’m appalled by the manosphere and these misguided and misleading versions of masculinity, which only serve to undermine the capacity of men and boys to have meaningful and mature human relationships," he said. 85 percent were published by individuals rather than health organisations, 67 percent included direct purchase links and 72 percent had financial interests, such as selling tests, supplements or clinic consultations. None of the posts included in the study cited scientific evidence to support their claims. "How am I going to build muscles like a man, if I have testosterone levels like a female? In the manosphere, testosterone is positioned as a way for men to reclaim power, status and control, the study says. Researchers at the University of Sydney have found influencer marketing is encouraging young men to undergo unnecessary testosterone testing and start hormone therapy – and minimising potential medical consequences. Some men and women experience immediate side effects of testosterone treatment, such as acne, disturbed breathing while sleeping, breast swelling or tenderness, or swelling in the ankles. However, the wisdom and effectiveness of testosterone treatment to improve sexual function or cognitive function among postmenopausal women is unclear. As surprising as it may be, women can also be bothered by symptoms of testosterone deficiency. For example, a man with osteoporosis and low testosterone can increase bone strength and reduce his fracture risk with testosterone replacement.