What happens if you forget a dose of anti rejection meds?

Depends: If you miss just one dose of anti-rejection meds, the risk of that precipitating a rejection is likely low. However, it is the repeated non-compliance with meds that often leads to poor patient and graft outcome. I encourage patients to have extra meds with them if they are going out (in case they cannot get back in time). Your immune system has a very good long-term memory.