Hello, I've Just Been Prescribed 18 Mg Generic Concentra; To

Hello,

I've just been prescribed 18 mg generic Concentra; to be taken in the morning orally. I workout and usually take stimulant preworkout, creatine, bcaa's, and whey protein. I understand combining stimulants is not a grand old idea. I'm wondering what supplements can I take for working out. They make non-stimulant preworkouts but I am not even sure if those are safe. And yes, I need the preworkout :)