Phenphedrine is a weight loss supplement that contains mostly stimulants including caffeine (in the form of Dicaffeine Malate) and therefore anyone with adverse events associated with stimulants should avoid using the product. It also contains one of the 12 ingredients that Med-Watch says to stay away from, including yohimbe, especially if you are taking antidepressant medications. There is a concern that using yohimbe with large amounts of herbs or products that contain caffeine might increase the risk of developing high blood pressure. Caffeine-containing herbs include coffee, cola, guarana, mate, and tea.