Bitter Orange Plus Caffeine Does Not Increase Cardiovascular Stress

A new study published in the International Journal of Medical Sciences has concluded that a weight-management supplement containing bitter orange, caffeine, and green tea did not lead to increased cardiovascular stress.

The double-blind, placebo-controlled crossover study was performed on 23 mildly overweight subjects. Over a 24-hour period, subjects consumed four capsules, with each capsule containing: 13 mg of p-synephrine from bitter orange (specifically, Advantra Z, a branded bitter orange ingredient from West Caldwell, NJ-based Nutratech Inc.), 176 mg of caffeine in the form of guarana extract, and 55.5 mg of green tea extract.

Subjects’ heart rate and blood pressure were monitored, as well as expired air. The researchers concluded that the supplement did not affect heart rate, systolic and diastolic blood pressure, or mean arterial pressure. They said blood pressure in hypertensive subjects did not change significantly after supplementation.

Nutratech notes that this study using Advantra Z involved more subjects, as well as multiple rather than a single dose, compared to previous studies involving Advantra Z.

J Seifert et al., “Effect of Acute Administration of an Herbal Preparation on Blood Pressure and Heart Rate in Humans,” International Journal of Medical Sciences, vol. 8, no. 3 (published online March 2, 2011): 192-197.