This study was performed to examine if the effects of collagen supplementation from pork skin could improve the sex steroid hormone, serum lipid and skin crack in Korean middle-aged women. Middle-aged women (40-55 years) who were not diagnosed with any type of disease were included in this study and thirty subjects were randomly assigned to a control group (n = 15) or a collagen supplemented group (n = 15). The collagen supplemented group ingested collagen flour 2 g, 3 times a day for 12 weeks. We measured serum collagen, estrogen, estradiol, estriol, progesterone, total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol concentration. The collagen supplementation group had significantly increased serum collagen (p < 0.05) compared with the control group. In addition, skin crack was improved. But, there were no differences for sex steroid hormone and lipid profile in control and collagen supplemented groups. The result of the present study demonstrated that supplementation of 6 g collagen per day for 12 weeks can give beneficial effects on skin crack reduction and serum collagen concentration.