As a blood donor, you can double the impact of your donation by participating in what is called Double Red Blood Cell Collection. This approach enables donors to donate two units of red blood cells at one visit, saving time on paperwork, travel, phone calls and the number of finger sticks per year. Because of the significant and ongoing need for red blood cells in our community, please consider a donation of red blood cells. By donating exclusively red blood cells, you can help fulfill the transfusion needs of two patients. You can donate double red cells every 16 weeks or 112 days. There are some special requirements when you donate double red cells: Donors must be in good health, be at least 16 years old and have a minimum hematocrit of 40%. Males must weigh 130 pounds and be at least 5’1”, Females must weigh 150 pounds and beat least 5’5”, in height.