... blood pressure and heart- rates warrants longer term studies to assess its value as a weight control agent. Key words: p-Synephrine, naringin, hesperidin, resting metabolic rate, heart rate, blood ... (juice or fruit, glycoside or aglycone, capsule, tablet, etc.) [4-8]. Experiments involving human subjects, animals and cell culture systems have shown that the two flavonoids exhibit ... well as athletic perfor-mance [21]. p-Synephrine is the primary protoalkaloid in bitter orange extract which is derived from the immature fruits of Citrus aurantium [22-25], and ...