That all depends, all drugs whether they are prescription or non-rx can have possible adverse events. Drugs that are prescribed with your Doctors supervision are probably, but not always the safest. This sometimes depnes on each indiviuals genetic makeup. What works well for one individual, may not work well for another. When it comes to illegal drugs...cocaine, marijuana and other less desirable-if these drugs are used carelessly, than they will certainly cause just as much, or not more harm than prescribed drugs for heart disease, diabetes etc... Hope I have assisted in answering your question somewhat.