Hair Transplantation side effects are minimal. Itchy scalp and some minor swelling can occur after a hair surgery. However, hair transplantation side effects compared to other cosmetic surgeries are hardly even noticed. The only time hair transplantation side effects can be noticed are if a patient has an allergic reaction to the local anesthesia provided. Also, if a patient does not take the doctors post-operative advise then hair transplantation side effects can become more serious. The most important things before and after a surgery are to disclose any medical conditions and to take your doctor’s post-operative advise.