Tobacco is a potent toxin. The testicular artery can also go into spasms if it gets choked with nicotine prolactin levels in smokers tend to be higher, so sexual desire ‘disappear in smoke’. Heavy cigarette smoking involves more than just nicotine it leads to the accumulation of large amounts of carbon monoxide in the blood, which impairs an efficient supply of oxygen to the cell. Thus heavy smoking tends to decrease sexual capabilities. The cadmium in smoke interferes with zinc metabolism and can accumulate in the testicles. Without enough zinc, testosterone levels are low. Without enough testosterone sex drive can not get into gear.