"without side effects" is a hyper-bold statement, to be really sure about side effect any drug demand around 10 years after a certain level of adoption... For

"without side effects" is a hyper-bold statement, to be really sure about side effect any drug demand around 10 years after a certain level of adoption... For instance vasectomy for years was considered "safe" even if "definitive" know we know, at least many suggest that vasectomy increase risk of prostate and testicular cancers. So far the only "permanent" (well, for a certain number of years) contraceptive method we have is the copper IUD, it have menstrual cycle side effect but nothing irreversible or really dangerous.