Updated: "How long will it take to replenish the pint of blood I donate? Your body will replace the blood volume (plasma) within 48 hours. It will take four to eight weeks for your body to completely replace the red blood cells you donated. The average adult has eight to 12 pints of blood." Google search, multiple confirms. Checked with my mom (former nurse) this is more acurate than most.

Any doctors here that can cobtribute?

A pint a week is max before your blood level gets too low and you start to pass out. If you give two pints in a week, you must be given fluids to compensate, plasma maybe to help with volume, and that may not be enough. Any doctors here that can cobtribute?