Establishing the apparent relationship of smoking to decreases in the quantity and quality of sperm would require much more research. Hormones Cigarette smoking significantly alters concentrations of the sex hormone testosterone, growth hormone, and other hormones in men. Male cigarette smokers have less testosterone than do male nonsmokers. Men with low testosterone concentrations have a lower sex drive and lower sperm counts than do those with normal or high concentrations of the hormone. In numerous studies cigarette smoking has been linked to a doubling of the incidence of erectile dysfunction.
Smoking diminishes blood flow both in the heart and in the penis.
Heavy smoking has been connected to a high risk of impotence. How cigarette smoking affects sex drive and sexual satisfaction was investigated in a 1999 study of 290 couples undergoing treatment for infertility. None of the female subjects smoked. On avarage the cigarette-smoking subjects stated that they had sex about six times a month, while on average the nonsmokers said that their lovemaking was about twice as frequent. Moreover, nonsmoking couples described their sexual satisfaction more approvingly than did those couples in which the male smoked.