Caffeine and aspirin were once used in combination with ephedrine in dietary supplements for weight loss. They're also found together in pain relievers, often with acetaminophen or butalbital. Caffeine should be used in moderation, and you should use aspirin only to treat mild to moderate pain or reduce fever or inflammation. A doctor may advise you to use it for other reasons, such as heart attacks, strokes and angina prevention.
In a 2003 study in the "International Journal of Obesity and Related Metabolic Disorders," P.A. Daly and colleagues found that a combination of ephedrine, caffeine and aspirin could lead to modest, sustained weight loss. However, the Food and Drug Administration, or FDA, banned dietary supplements containing ephedrine in 2004 because of "unreasonable risk of illness or injury."
According to Drugs.com, common side effects of ephedrine are anxiety; confusion; difficulty sleeping; dizziness; headache; nausea; nervousness; pale skin; restlessness; sweating; tension; tremors; and weakness. Less common, severe side effects include severe allergic reactions, characterized by rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; chest pain; difficulty urinating; eye pain; hallucinations; increased irregular heartbeat; nausea; pounding in the chest; and vomiting. A 2000 study by Christine A. Haller and Neal L. Benowitz published in the "New England Journal of Medicine" found that ephedrine supplements could lead to hypertension, palpitations, tachycardia, stroke, seizures, and even death and permanent disability.
Caffeine may cause slight weight loss or help you maintain your weight, according to MayoClinic.com. Caffeine may lead to temporary appetite suppression or increase the amount of calories that your body burns. It may also cause water loss, causing short-term weight reduction. Aspirin on its own does not appear to spur weight loss, but may increase the effects of ephedrine, according to a 1987 study by A.G. Dulloo and D.S. Miller published in the "American Journal of Clinical Nutrition."
Studies do not show that weight loss from caffeine is permanent, and many studies were poor quality or only looked at caffeine's effect on animals, according to MayoClinic.com. Caffeine can be habit forming. Some people are more sensitive to its effects than others. Keep intake moderate. According to the McKinley Health Center of the University of Illinois at Urbana-Champaign, 300 mg of caffeine, or about the amount contained in 3 cups of coffee, is moderate intake.
Caffeine can make you restless, anxious and irritable. It can also cause dizziness. Seek immediate medical attention if you have a severe allergic reaction, characterized by rash, hives, itching, difficulty breathing, tightness in the chest and swelling of the mouth, face, lips or tongue. Contact your health care provider if you experience diarrhea, shakiness, trouble sleeping or vomiting. Prolonged use of aspirin is not recommended unless a doctor advises you to use it for prevention of heart attack and stroke.