@annshrader when I did it in 2019, dr. suggested I try 1 a few months (2020)later for reinforcement and I did and then I opted for one a few years(2022) later. I think of it as blood doping - Haven't had one since. I do know many others that had no positive results. It's still in its infancy. That process worked for me. I even saw the whole process for drawing and centrifuging your blood improve.