The Facial Hair Cream is intended to slow hair growth, and works best when used alongside a hair removal method. For The Facial Hair Cream Bare (Eflornithine 6%, Dimethyl Sulfoxide 10%), shaving is specifically recommended because it leaves the hair follicle intact.
Tweezing, however, pulls the hair out from the root, and since Eflornithine works by slowing hair growth at the follicle level, removing the hair bulb can temporarily reduce how much target structure the medication has to act on. In other words, frequent tweezing may make the treatment less effective or slower to show results compared to shaving.