Diuretics
These drugs have long been popular among bodybuilders and athletes in sports that have to “make” a certain weight, like boxers and wrestlers. But while they do help you drop pounds fast, it’s not real weight loss you’re seeing, Full says. “Diuretics were never intended for weight loss; their purpose is to help the body excrete excess water and salt,” she explains. “Any weight you lose would be purely from water.” Worse, if you take more than the recommended dose it can lead to dangerous side effects such as dehydration, dizziness, muscle cramps, weakness, confusion, heart palpitations, increased blood sugar, nausea, she adds.