You may have heard that your body essentially regenerates every seven years, but, like many ideas traveling from person to person, it's not exactly that simple. The idea that your whole body is new every seven years is basically a myth, but many of the cells in your body do change over regularly. It's just that the different kinds of cells and different parts of the body change and regrow at different rates. The shocking ways your body changes about every few years might be interesting for you to know, particularly if you thought that it was true that your entire body changes every seven years.
Some of the cells in your body turnover every couple of days, others take weeks, months, or even years. Some may or may not really ever turn over. Researchers are still discovering the ways some of these things might work (or exploring how stem cells might change the way cells work). It seems that there are very few hard and fast rules about how rapidly your body changes this way. In a video, Brain Stuff noted that your body generally renews over the course of seven to 15 years, but clarified that the different parts of your body take different lengths of time to replace themselves. There are different things changing all the time. If you're interested in which body tissues turn over every few years, here's what you need to know.