Sue, DHEA is a hormone, I believe it is from an animal, maybe a horse, I really don't WANT to know that part! I buy it at Sam's Club, it costs I think $12.95 for 300 of I think, 25mg tablets. I originally bought them in a health food store for $6-7 a hundred, so shop around! I don't have PD, so I don't know if it would interfere with PD meds. I think a possible side effect is Prostate cancer, you would not have to worry about that. I figure, that since it is something that already occurs in the body, it should not be harmful, but PLEASE check with a doctor, before taking a chance. Good luck! Ken B