What Natural Remedies Can Help With ED In A Kidney Transplant Patient On Anti-rejection Meds And Eliquis, With Minimal Side Effects?

Hello, I suffer from ED. I have a kidney transplant, I’m very healthy now, taking anti rejection medications along with Eliquist. I’m 39, good build but my erections do not last long. Typically 20-30 mins, sometimes less. I’ve been trying to find a natural medicine that will help me with the least amount of side effects. Help? Please :(