You've probably heard the horror stories about the side effects of Fen-Phen and Redux.
Side effects vary from person to person.
Minor side effects are generally mild and transient, while major side effects are rare and typically only occur with long term use. Ephedrine has been associated with some deaths and is dangerous for those with cardiac conditions. Minor side effects include insomnia, dizziness, anxiety, palpitations, nausea, and vomiting. Major side effects include convulsions, chest pain, hypertension, shortness of breath, and cardiac dysrhythmias. There can be problems with FDA-approved drugs also.