It appears, according to scientific data, that nicotine will not affect (i.e. reduce) estradiol concentrations if exogenous estradiol is taken non-orally. But, nicotine/smoking is in general not advised for its health risks, including increasing risk of blood clots. The sooner you quit, the better but I know it can be hard. I used to be a smoker but in the end, it's soooooooo worth it! ๐