There is no doubt in my mind that smoking impacts circulation negatively. I’m sure there are reams of data pointing to this, but my personal experience as a smoker is most tangible. In general, I have to say all possible states of my penis appear reduced; regular size can be attained, but only with greater stimulus, and flaccid state has less volume, period.
Obviously, there is likely a ‘recipe’ for my reduction in general penis health. Aging, weight gain, sexual activity, etc. However, I believe smoking contributes as much or more as any other factor. I’m tapering currently, and intend to stop.