Stimulants are substances that stimulate your central nervous system, increase your heart rate and elevate your blood pressure. Caffeine and ephedrine are commonly used stimulants that are available over the counter. Stimulants may be used as part of your daily routine, such as a cup of coffee in the morning to promote wakefulness. Stimulants are also used to aid in weight loss and by athletes to improve performance.
Caffeine can be found in coffee, tea, soda and over-the-counter pills. Caffeine offers a number of benefits, including its ability to alleviate fatigue, increase wakefulness and improve concentration and focus, according to the Mayo Clinic. Caffeine also works as an appetite suppressant. Consuming more than 200 to 300 mg or the equivalent of four cups of coffee per day can result in a number of side effects, including insomnia, irritability, restlessness, increased heart rate and muscle tremors.
Ephedrine has a number of effects on your body. It is used in asthma and cold medications for its bronchodilator and decongestant properties. It also works as an appetite suppressant and stimulant. For this reason, it is popular among athletes and those wishing to lose weight, says the Mayo Clinic. However like caffeine, ephedrine has a number of side effects, including insomnia, dehydration, heart palpitations and tremors. Taking doses much higher than the recommended dose may result in stroke, circulatory problems or heart attack, the Mayo Clinic says.
The use of ephedrine or the combination of ephedrine and caffeine is associated with a two- to three-times risk of nausea, vomiting, mood changes and heart palpitations, according to a 2003 government-sponsored review published in the "Journal of the American Medical Association." The use of ephedrine has been banned by a number of sports agencies, including the NFL and NCAA.
Like ephedrine, caffeine has been the subject of controversy among athletic organizations. Sports organizations, including the International Olympic Committee, screen urine for acceptable levels of caffeine. A positive drug screen may result from drinking the equivalent of eight cups of coffee. When consuming caffeine or ephedrine, use them in moderation, and do not exceed the recommended dose. Both caffeine and ephedrine may interact with medication. Consult your doctor to determine if caffeine or ephedrine is safe for you.