That would prob depend on the agency/office you went through, but typically they try to have donors between 21-29. You never know though. I'm about to do my 6th donation and recently found out that a lot of obese couple use donors, and that made me angry. I don't want a potential child of mine out in the world being obese. Ugh. Most agencies have BMI restrictions for donors, and that is what the Facebook comments are about.