Hi Liz, As a frequent donor of platelets, here is my experience. If you donate a singe or double apheresis unit, you are eligible to donate again in 14 days. If you donate a red cell product along with a platelet, you are deferred for 56 days, just as if you donated red cells only. In special circumstances, donor centers can waive the 14 day rule if they are requesting that the donor give an HLA-matched product, as long as the donor passes other eligibility requirements, such as HGB>12.5. Hope that helps! Terry aka BB in VA