It takes about 4 to 8 weeks for eyebrows to grow back after shaving, and some measures can be taken to promote the growth of eyebrows. Eyebrows and other parts of the body hair is the same, its hair follicle growth also has a growth period, regression, resting period of three stages. Generally, hair growth can be seen in the follicle during the anagen phase, and the hair in the follicle may fall off after entering the anagen and resting phases. To summarize, eyebrows in the anagen phase follicles will continue to grow, but eyebrows in the degenerative and resting phase follicles will grow slower and even fall off, and it will take 3 to 9 months for these two phases of eyebrow hair to grow again. However, shaving the eyebrows will stimulate most of the eyebrow hair follicles to shift to the anagen phase. The growth rate of eyebrow hairs in the anagen phase follicles is 0.16mm per day, and the normal length of eyebrow hairs is about 5-8mm, so it will take about 4-8 weeks for the eyebrow hairs to grow out completely. In addition, some measures can be taken to help promote the growth of eyebrows, such as strengthening physical exercise, to maintain endocrine stability, which helps to promote the growth of eyebrows; pay attention to maintain a relaxed mood, to develop a good habit of regular work and rest, to stabilize the level of various hormones in the body, which will help the growth of eyebrows, and so on. It should be noted that, if the eyebrows shaved after the delay in the growth, it is recommended to go to the regular medical institutions in a timely manner, to exclude other diseases caused by hair growth difficulties, so as not to delay the treatment.