Bitter Orange

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Bitter Orange (Citrus aurantium)
  Evaluated for:
Effectiveness Rating Effectiveness Rating
Weight Loss
0 (Unclear Effectiveness)


  • Bitter orange (Citrus aurantium) is derived from the immature fruit of the Seville orange, a flowering, fruit-bearing evergreen originally native to tropical Asia that is now cultivated throughout the Mediterranean.
  • The primary active constituent of bitter orange is p-synephrine, an alkaloid with properties similar to those of ephedrine.
  • Bitter orange is frequently combined with agents such as caffeine or other herbal supplements in products advertised for weight loss.
  • Studies have shown that bitter orange may aid in weight loss by increasing metabolic rate and energy expenditure. It may also increase the thermic effects of food.


  • Bitter orange contains a stimulant called synephrine. When taken in high doses or in combination with other stimulants such as caffeine, it has the potential to raise blood pressure and cause cardiovascular problems. A single dose of synephrine 6% (54 mg) has been show to increase blood pressure and heart rate in young, healthy adults.
  • Bitter orange is similar to ephedrine, a substance that was banned by the FDA in 2004. Since then, it is commonly substituted for ephedrine in weight loss supplements.
  • Bitter orange use may increase the activity of certain prescription medications such as for blood pressure, fungal infection, and depression.
  • Current studies do not show a significant weight loss effect with bitter orange.
  • Bitter orange has been banned by the National Collegiate Athletic Association (NCAA).

A lack of product standardization may increase the risk of harmful side effects.

DOSAGE:Limit use to bitter orange products that specify between 1% (9 mg) and 6% (54 mg) synephrine. Increased synephrine content to as much as 30% (270 mg) by certain manufacturers may increase the risk of harmful side effects.

CONCLUSION: If you elect to try Bitter Orange, remember to include it in your list of medications when you visit your doctor and other health care providers.