China’s blood donation law stipulates that the interval between blood donations cannot be less than 6 months, i.e. you can donate blood again after 6 months between donations. The reason is that when donating blood, the body loses some blood, including various blood cells and plasma, of which white blood cells and platelets have a faster recovery time, and plasma components also have a faster recovery time, generally in about a week to the level before donating blood. However, red blood cells recover more slowly, because the average life span of red blood cells is about 120 days. After about 3 months of levels, the number of red blood cells can return to the level before blood donation, i.e. it is safe to donate blood again after an interval of 3 months. However, in order to ensure the health of the donor and the quality of the blood, China requires a 6-month interval before donating blood again.