... Effects of p-Synephrine alone and in Combination with Selected Bioflavo-noids on Resting Metabolism, Blood Pressure, Heart Rate and Self-Reported Mood Changes Sidney J. Stohs1, Harry G Preuss2, ... weight control agent. Key words: p-Synephrine, naringin, hesperidin, resting metabolic rate, heart rate, blood pressure Introduction The bioflavonoids hesperetin and naringenin are widely distributed ... particularly in caffeine-sensitive individuals [39]. The absence of changes in blood pressure, rest-ing heart- rate and self-ratings in the four treatment groups involving p-synephrine, naringin and...