Natural Bitter Orange Component Twice as Active as Synthetic, Review Says

A new scientific review states that the naturally occurring form of p-synephrine, an ingredient present in bitter orange extract, exhibits at least twice the physiological activity as does the synthetic form of p-synephrine.

The review by Sidney J. Stohs, PhD, called “Stereochemical and Physiological Differences Between Naturally Occurring p-Synephrine and Synthetic p-Synephrine,” states that synthetic p-synephrine enables only one-half of a synthetic p-synephrine formula to bind to receptors. By stimulating beta-3 receptors, p-synephrine can help to increase thermogenesis and lipolysis.

Stohs is Dean Emeritus at the School of Pharmacy and Health Professions at Creighton University Health Sciences Center.

The natural form of p-synephrine is present in Advantra Z, a patented bitter orange extract from Nutratech Inc. (West Caldwell, NJ). The ingredient is touted as an all-natural thermogenic ingredient for weight loss, fitness, and energy. Stohs’s review also points out that natural bitter orange extracts contain flavonoids and other protoalkaloids that synthetic versions do not.