$25 , $30, after that goes to $15 and $30. So they pay you the 25$ for the first time during the week and to get you back, they pay $30 for the second time. So as you can see becoming a regular donor can pay off nicely! How often can one donate? You can donate plasma up to two times in a seven day period. Also, make sure that you are in good health. Don’t go to donate if you are even feeling just a bit on the sick side, because you can get really ill if you do…like fever of 103 degrees. Additional Eligibility Requirements: To donate plasma, you must be a healthy and at least 18 years old +, weigh at least 110 pounds, and pass all other required donor eligibility criteria.