Answer: benadryl's generic name is diphenhydramine hydrocloride.In theory, diphenhydramine is not an addictive substance. It functions by blocking the histamine at the HA- receptor sites. It is an antihistamine of ethanolamine class, which have significant antimuscarinic activity and generally make people feel groggy and tired.It is quickly absorbed into the body within one hour, and has a half life of one to four hours. In general, if you take it before bed, its mostly processed through your body before you wake up the next morning.Side effects you may get from taking diphenhydramine could be (anticholinergic side effects) loss of coordination, dry mouth, decreased mucus production, increased heart rate, an increase in boty temperature, agitation, short term memory loss, confusion..If you mean specifically taking diphenhydramine seven days a week three hundred sixty five days a year having bad side effects, the answer is generally no, unless you have a liver/kidney problem, or being groggy as heck all the time bothers you...If you do have liver/kidney problems, I recommend you bring up your sleep issues with a physician who can recommend different drugs or different dosing dealing with your medical problem.A personal note here... I'm a chronic insomniac, and frequently for me, there's some underlying issue when I need to constantly drug myself to get some restful sleep. Figuring out what these issues are and addressing them usually gets better results than taking medications to help me sleep.If you have an underlying issue why you can't sleep restfully, I suggest you consider looking into it and/or resolving it. It may really help in the long run.