Can Bitter Orange Help You Lose Weight?

Bitter Orange (Citrus Aurantium): An Alternative To Ephedrine

The fruit from a plant called Citrus Aurantium is used to create Bitter Orange Extract. This extract contains several alkaloids that are similar to ephedrine: synephrine, N-methyltyramine, hordenine, octopamine, and tyramine.

Unlike ephedrine, some of the alkaloids in Bitter Orange are believed to act specifically on beta-3 adrenergic receptors which promote fat breakdown. In contrast, ephedrine additionally acts on beta-1 and beta-2 adrenergic receptors, which stimulate the central nervous and cardiovascular systems. Thus, Bitter Orange is promoted to offer the same stimulant effects as ephedrine (increased metabolic rate, decreased appetite, improved energy levels) without the adverse side effects.

There are a limited number of published clinical trials examining the effects of Bitter Orange in humans but there has been work done involving in vitro (experiments done in a laboratory dish), animal models, human studies described in patents, and even a few published human studies that generally support the idea that Bitter Orange is a safer alternative to ephedrine for weight loss.

A recent study examined the effectiveness of Bitter Orange in combination with caffeine and St. John's Wort versus placebo in overweight men and women following a weight loss program that involved a low-fat reduced calorie diet (1800 kcal/day) and regular exercise (3 days/wk). Compared to the placebo group, subjects in the Bitter Orange group lost more body weight and body fat and increased their metabolic rate after just 6 weeks. There were no reported side effects or adverse responses in markers of renal, liver, and cardiovascular function. Although this was a small study, the results do support the notion that the mild stimulants in Bitter Orange may offer benefits for weight loss and provide a safer alternative to the more potent adrenergic agonist ephedrine.