Overview

Citrus aurantium, commonly referred to as bitter orange, has been used for thousands of years in Traditional Chinese Medicine to improve and maintain overall health. That is, until recently, when science discovered compounds (the most well-known being synephrine) from these little orange fruits demonstrated equally powerful thermogenic ("fat-burning") activity. In fact, synephrine is referred to as ephedra's "calmer chemical cousin" because it increases the body's metabolic rate or ability to burn calories, without producing negative side effects on the central nervous system and the cardiovascular system.

Usage

Amount: Research indicates that 4 to 20 mg of synephrine per day, which usually is provided by supplementing with 200 to 600 mg of a standardized Citrus aurantium extract (3 to 6% synephrine), may be effective.

If you're brave, you can stick the crushed peel in some hot water and "savor" a really bitter tea. Use 4 to 6 grams per day of cut peel for teas or 2 grams in 150 ml or boiled water 3 times a day. Alcohol solutions (tinctures) and liquid extracts are another (more enjoyable) way to take it.

Important Note: According to recent data, it appears that using the whole fruit extract is the best way to take Citrus aurantium since there are many additional chemicals in the plant besides synephrine that are used for increasing the metabolism, and we're only beginning to understand their total, combined effects.

Timing: For weight loss, use in evenly divided doses throughout the day, preferably on an empty stomach. For stimulant effects, use 30 to 45 minutes before exercise, again, without food.

If you use ephedra and are feeling a little too amped up, or if you have considered using ephedra and are concerned about potential (unwanted) side effects, Citrus aurantium might be just what you've been waiting for. Science has discovered this little orange fruit, sometimes called bitter orange, may still give your body a quick "boost" of energy as well as rev up your metabolism to assist your fat-fighting efforts without the undesirable effects of ephedra-based supplements.

Questions and Answers

Q.	What does the research on Citrus aurantium show?
A.	Because Citrus aurantium or, more specifically, its most active ingredient, synephrine, is a stimulant, similar to caffeine and ephedra, research suggests it may have similar effects in terms of providing an energy boost, suppressing appetite, and increasing metabolic rate and calorie expenditure.
Q.	Could any other supplements make Citrus aurantium even more effective?
A.	The effects of Citrus aurantium in combination with other ingredients, such as kola nut and guarana (which are caffeine sources) or HCA may improve its actions as a mild stimulant.
Q.	What's the most common amount of Citrus aurantium used to achieve optimal results?
A.	Although synephrine is but one small component of the Citrus aurantium fruit, a standardized extract is recommended. A dose of 4 to 20 mg of synephrine per day is a typical dose found in products providing 200 to 600 mg of a standardized Citrus aurantium extract (3 to 6 percent synephrine).
Q.	Can too much Citrus aurantium cause any side effects—is it safe?
A.	Isolated Citrus aurantium extract in large dosages has been shown to raise blood pressure in animal studies. Until more studies are conducted on its safety, it should be treated as a nutrient with mild stimulant properties and should be avoided by individuals with cardiovascular concerns such as hypertension (high blood pressure).
Q.	What is the difference between ephedra and Citrus aurantium?
A.	Citrus aurantium and ephedra are considered chemical cousins, but their effects on the body are quite different. While they're both stimulants, the effects of Citrus aurantium are much less dramatic than the negative effects often experienced with use of ephedra alkaloids.

Safety Information

Safety:
Both isolated synephrine and Citrus aurantium extract can crank up your blood pressure, so if you've got heart problems or high blood pressure, it may be best to avoid it. Synephrine causes a rise in blood pressure by triggering vasoconstriction (tightening of your vascular system or blood carrying network). Like many natural supplements, avoid use during pregnancy or lactation.

Known drug interactions:
Do not combine with heart or blood pressure medications.

Toxicity:
Like most bitter herbs, there is stuff in here you don't want to be messing with. Try to avoid rubbing raw Citrus aurantium (the fruit) all over your body since the peel can irritate the skin and even make you more sensitive to sunlight due to the phototoxic effect of furocoumarins.

Bans and Restrictions:
Some experts have theorized that synephrine may show traces of alkaloids in the body similar to ephedra, but more research is needed to verify if this is, in fact, the case. At present, synephrine is not on any banned list. Still, if you are an elite athlete who is regularly drug tested, it is recommended that you discuss supplementation with your physician before use.

References

Candelore, M.R., et al., "Potent and Selective Human Beta(3)-Adrenergic Receptor Antagonists," J Pharmacol Exp Ther 290.2 (1999) : 649-55.

Chen, X., et al., "The Effects of Citrus aurantium and its Active Ingredient N-Methyltyramine on the Cardiovascular Receptors," Yao Xue Xue Bao 16.4 (1981) : 253-9.

Colker, CM., et al., "Effects of Citrus aurantium Extract, Caffeine, and St. John's Wort on Body Fat Loss, Lipid Levels, and Mood States in Overweight Healthy Adults," Curr Ther Res 60 (1999) : 145-53.

Fontana, E., et al., "Effects of Octopamine on Lipolysis, Glucose Transport and Amine Oxidation in Mammalian Fat Cells," Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 125.1 (2000) : 33-44.

Galitzky, J., et al., "Specific Stimulation of Adipose Tissue Adrenergic Beta 3 Receptors by Octopamine," C R Acad Sci III 316.5 (1993) : 519-23.

Hu, S., and Wang, G., "Textual Studies on Shangzhou Zhiqiao Fructus Aurantii," Zhongguo Zhong Yao Za Zhi 21.3 (1996) : 137-8, 189.

Miyazawa, M., et al., "Antimutagenic Activity of Polymethoxyflavonoids from Citrus aurantium," J Agric Food Chem 47.12 (1999) : 5239-44.