Citrus aurantium, or bitter orange, comes from a flowering, citrus fruit-bearing evergreen tree native to tropical Asia, but is now widely cultivated in the Mediterranean region and elsewhere. It has been shown to provide excellent results at stimulating metabolism, increasing fat loss, facilitating uptake of amino acids into muscles, and mildly suppressing appetite.
There have been over two dozen research articles published on the safety and efficacy of Citrus aurantium since 1997.[i] The specific controversial concern has been on the active ingredient "synephrine" and its supposed negative effect of increasing blood pressure and heart rate. It is true that a particular molecular isomer of synephrine, or the “m-synephrine” isomer, is used to increase blood pressure in emergency medical situations. However, the form of synephrine occurring naturally in extracts of Citrus aurantium is the “p-synephrine” isomer. This is an important molecular distinction, not just for understanding the misunderstood claims about this herb in regards to heart rate and blood pressure, but realizing its potential for weight loss and metabolism enhancement.
Heart rate and blood pressure will increase if alpha-receptors are stimulated. Metabolism and fat breakdown (lypolysis) will increase if beta-2 and beta-3 receptors are activated. This is important because alpha-receptors bind with the m-synephrine, increasing heart rate, while the beta-receptors, found in Citrus aurantium, bind with p-synephrine, and aid in fat loss.
Avoid this completely during pregnancy and take extreme caution if you have any history of heart disease. Be sure to consult with your healthcare provider before you start any new supplement.
A standardized extract should be considered that ranges from 5% to 30% p-synephrine. The dose of actual p-synehprine, which will be different depending on the strength of the extract, should be from 100 to 120 mg total daily, divided into 2 to 3 doses.
Be sure to check with your qualified healthcare provider before starting any kind of weight loss program or starting any kind of herbal or nutritional supplement. This information is intended for awareness only and not for treatment.