Since nicotine is such a powerful and quick constrictor of blood vessels, it has almost immediate effects on genital blood flow. Studies using Doppler imaging have shown that the deeper arteries supplying blood to the penis immediately respond to cigarette smoke by clamping down so that no blood flow is visible after just two cigarettes. Note that this is about the same amount of nicotine that would be found in most nicotine gums or is slowly released from a nicotine patch. Although these spasm effects of nicotine do reverse after one quits smoking or stops using nicotine replacement, there is also long-term damage to the lining of the arteries, as well as the nerves.
This damage, which is caused by the nicotine along with some of the other smoke components, increases over time to the point where it is irreversible. Some of these components include:
- Carbon monoxide
- Ethelene gas
This cumulative damage keeps the arteries from responding to sexual stimulation so that there is no further relaxation of those blood vessels to allow proper blood flow for an erection. In fact, researchers have found that the decrease in nighttime erections is directionally proportional to the number of cigarettes one smokes. (For more information on erectile issues, please consult Good in Bed's free mini-guide on the topic).