AKA: Citrus Aurantium, Bitter Orange, N-Methyltyramine
The Mythology: Organic Ephedra, that burns fat without all those nasty ephedra side-effects like anxiety and death.
The Truth: Shows promise but early days yet in terms of good trials. Give us one good study.
Research: With the increasing media concern and eventual FDA ban on Ephedra as an OTC weight loss supplement, the industry has been scrambling around looking for replacements. Several of them have repackaged old favorites, swapping Ephedra for Citrus Aurantium, claiming it has equal or better weight reduction properties than Ephedra, but does it?
Compared to Ephedra, Citrus Aurantium is just too much of a new kid on the block to tell one way or the other. Lab rats on CA show definite weight reduction and the pharmacological story adds up. On the other hand the list of rodent friendly supplements that have let us humans down is too numerous to name. To my knowledge only three trials have explored the effects of Citrus Aurantium on humans.123 One was open labeled 2 (i.e. No placebo involved, people know what they are getting. These studies typically over-estimate results big-time) So make that – 2 trials. Both these trials consisted of small numbers of individuals who were untrained. Also the preparations were mixed. In one study CA was combined with caffeine and in another CA was combined with ephedrine. Since caffeine and ephedrine have a significant amount of evidence as anti-obesity drugs, those 2 trials don’t really tell us very much about CA in and of itself.
Nevertheless this is a promising compound which needs to be further researched. I’m really hoping someone gets on the band-wagon fast and puts me out of my misery. My guess is that it will not pack quite the punch as Ephedra, but will have a much better side-effect profile leading to greater tolerability.
1. Colker CM, Kalman DS, Torina GC, Perlis T, Street C, Effects of Citrus Aurantium extract, caffeine, and St. John’s Wort on body fat loss, lipid levels, and mood states in overweight healthy adults. Current Therapeutic Res 1999; 60: 145–153.
2. Jones D, Regulation of Appetite, Body Weight, and Athletic Function with Materials Derived from Citrus Varieties. Patent 6224873. 2001 May 2001.
3. Kalman DS, Colker CM, Shi Q, Swain MA, Effects of a weight-loss aid in healthy overweight adults: double-blind, placebo-controlled clinical trial. Current Therapeutic Res 2000; 61: 199–205.
4. Armstrong WJ, Johnson P, Duhme S, The effect of commercial thermogenic weight loss supplement in body composition and energy expenditure in obese adults. Journal of Exercise Physiology 2001; 4: 28–35.
Haaz S, Fontaine KR, Cutter G, Limdi N, Perumean-Chaney S, Allison DB, Obes Rev. 2006 Feb;7(1):79-88. Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update.
How it works: Citrus Aurantium contains phytochemicals such as p-Octopamine and synephrine alkaloids (SAs) including N-Methyltyramine, Octopamine, Hordenine and L-Tyramine. These molecules are adrenergic agonists and are said to be responsible for weight loss properties of Citrus Aurantium. As a sympathomimetic agent with both alpha and beta adrenergic receptor agonist properties, SAs would be expected to increase energy expenditure and decrease food intake. In addition, there is some evidence that SAs, decrease gastric motility.
Adverse effects: Some case reports of increased blood pressure. No consistent findings. Data too sparse to make definite conclusions. C. aurantium contains 6′,7′-dihydroxybergamottin and bergapten, both of which inhibit cytochrome P450-3A, and would be expected to increase serum levels of many drugs.