Question: how long does it take to gain weight on birth control shot?
Answer: Fact 2: The shot can lead to weight gain for some women. Here's what we have seen: the birth control shot (Depo-Provera) can cause weight gain for about a quarter of users. A recent study showed that, in the first six months of use, 1 out of 4 shot users gained 5 percent or more of their starting weight.