Recombinant Erythropoietin (r-HuEPO) is a synthetic copy of a natural human hormone responsible for stimulation of red blood cell production. It can take up to several weeks to see the results from an injection of EPO. If you look this up on the internet, you will find a site that has lots of information, I think it is noblood.org. I don't know if this is a religion-based website or not, but the technical info is good.
Hope this helps
Andrea from Boston

SCC L lat tongue,Dx 9/15/05 T1N0MX L MND and L lateral hemiglossectomy 10/03/05. Recurrence 11/15/06 2nd surgery 12/04/06 hemiglossectomy 3rd surgery 01/15/07 tonsillectomy Radiation 01/25/07 to 03/08/07 3-D/CRT X 30