Hair loss after starting testosterone injections can happen because testosterone may increase conversion to dihydrotestosterone (DHT), a hormone linked with male-pattern baldness in genetically sensitive people. Hair thinning may become more noticeable around the temples or the crown after hormone therapy begins. Stress, nutritional deficiencies, thyroid problems or rapid hormonal changes may add to the worsening hair fall. Doctors sometimes use treatments such as minoxidil or medicines that reduce DHT activity to slow hair loss, but these should be carefully chosen in people with hypogonadism because some treatments can affect hormone balance, libido or fertility. Blood tests for testosterone, DHT, thyroid function, iron, and vitamin levels may help identify contributing factors. Regarding fertility, sperm retrieval through testicular biopsy or micro-TESE may sometimes be possible in certain men with hypogonadism, depending on the cause and whether any sperm production remains in the testes. Hormonal evaluation, semen analysis, and a fertility specialist's assessment are usually important before deciding on the next step.