The proposed investigation will examine the hypothesis that approved dosages of phenylpropanolamine (PPA) and/or PPA/caffein present in over-the-counter diet medications can lead to a significant elevation in blood pressure during normal environmental conditions. Specifically, the goal of this study is to examine the blood pressure and pulse rate of normotensive and "borderline"-mild hypertensive females, both on and off birth control pills, during treatment with placebo, time release PPA (75 mg) and time release PPA (75 mg)/caffeine (200 mg) using a double blind randomized cross over design. The subjects will be fasted during the day, as though dieting, but allowed to drink usual fluids including caffeine-containing drinks (which will be recorded). Blood pressure (and heart rate) will be determined one hour prior and twelve hours after treatment using the recommendations of the American Heart Association. The data will be analyzed by a Ph.D. statistician. The importance of this study is that the issue of blood pressure elevation and its complications during PPA and PPA/caffeine ingestion will be clarified: ARE HYPERTENSIVE COMPLICATIONS RELATED TO THE APPROVED PPA DOSE SIMPLY IDIOSYNCRATIC IN ORIGIN OR ARE THEY AT ONE END OF A NORMAL VARIABILITY RANGE OF REACTION TO THE DRUG? This work will contribute substantially to one of my long-term goals: to determine if commonly used medications (especially) sympathomimetics) contribute to an acute elevation in blood pressure and possibly hypertension in our society.