Bitter orange is made from the peel of Seville oranges, so it sounds harmless, right? Unfortunately, this product can be very dangerous! It is found in many weight loss supplements labeled as “ephedra free”. Bitter orange might be just as dangerous as ephedra and can cause serious side effects such as high blood pressure, increased risk of heart arrythmias, heart attack, seizures, or even stroke. Consumer Reports magazine listed bitter orange as one of the Dirty Dozen, most dangerous supplements. Though made from orange peels, this product contains concentrated amounts of synephrine, which is similar to the potent chemical in ephedra. It also contains methyltyramine, which is known to raise blood pressure.
If you are taking any medications, you may be at particular risk if you also take bitter orange. Citrus aurantium has a substance in it called 6′,7′-dihydroxybergamottin. It inhibits a drug-metabolizing enzyme, so that drugs are cleared less quickly, and may build to dangerous levels. This is also found in grapefruit juice, which is why many prescription warning labels say to avoid grapefruit juice.
Bitter orange goes by many names, and is included in products such as Trimspa, Metabolife, and other similar products. It goes by many names. Read the labels carefully and look for bitter orange, citrus aurantium, green orange, kijitsu, neroli oil, Seville orange, shangzhou zhiqiao, sour orange, zhi oiao, or zhi xhi.