There are a number of side-effects due to Didrex being a stimulant. People with heart disease or high blood pressure should not take Didrex. It can cause insomnia, restlessness, anxiety, headaches, dizziness, dry mouth, diarrhea, or constipation.

Didrex is habit forming. You can become psychologically and physically dependent on it.

People who use Didrex will lose weight in the short term. But, in the long term they gain it back.