Bitter orange (Citrus aurantium) is the type of orange commonly used to make orange marmalade. Also known as Seville orange and bigarade orange, it lives up to its name as one of the most tart and pungent citrus fruits.
While the fruit and rind can be used for preserves and dessert, the peel and flower are often distilled to make bitter orange oil. The oil, used to make liqueurs such as Cointreau, Triple Sec, and Grand Marnier, are also believed to have medicinal properties.
Bitter orange is grown throughout the Mediterranean as well as parts of Florida and the Bahamas. In Chinese medicine, it is referred to as zhishi. When used for aromatherapy, bitter orange essential oil is believed to increase concentration and improve mood and fatigue.
Bitter orange is a tree native to Asia. The peel, flower, leaf, fruit, and fruit juice are used to make medicine. Bitter orange oil is made from the peel and flower.
People use bitter orange for conditions such as weight loss, upset stomach, and exercise performance, and many others, but so far, science has shown only that the oil, when applied to the skin, might be effective for treatment of fungal skin infections (ringworm, jock itch, and athlete’s foot).
Bitter orange contains an active ingredient called synephrine that is similar to ephedra. In 2004, the FDA banned ephedra for serious side effects on the heart. Many weight loss and bodybuilding products contain bitter orange and caffeine, which can cause high blood pressure and increased heart rate in healthy adults. There is concern that using bitter orange might cause heart problems.
While some research suggests that bitter orange (Citrus aurantium) can help with modest weight loss when combined with diet and exercise, it’s probably not worth the risk. That’s because bitter orange can cause a range of potentially serious health problems. So if you’re trying to lose weight, stick to healthier methods and skip the bitter orange.
Bitter orange fruit and peel are often used in weight-loss supplements and supplements sold for a variety of health concerns.
But bitter orange contains synephrine. This is similar to the main chemical in the herbal supplement ephedra (ma-huang), which the Food and Drug Administration banned because of the health problems it caused. Synephrine might speed up your heart rate and raise your blood pressure. Stroke and heart attack have been reported in some people using bitter orange alone or in combination with other stimulants such as caffeine.
Bitter orange is likely safe when consumed orally from dietary sources. Bitter orange has achieved a Generally Recognized As Safe (GRAS) status in the United States. Bitter orange essential oil is possibly safe when used topically or through aromatherapy. However, bitter orange may be unsafe when consumed orally as medicine; its extracts and juice have been safely used in the short-term but only under the supervision of a physician.
Though research has shown that synephrine increases the numbers of calories burned, its effect on weight loss is inconclusive (9Trusted Source).
Because bitter orange is often combined with other compounds — such as caffeine — in weight loss supplements, it’s difficult to interpret its effectiveness.
A review of 23 studies found that 20–35 mg of synephrine per day increased metabolic rate and had a modest impact on weight loss.
However, some of the studies resulted in no weight loss or even weight gain after treatment with synephrine (10Trusted Source).
Bitter orange, both taken by mouth and applied to the skin, has many uses. But so far, science has shown only that the oil, when applied to the skin, might be effective for treatment of fungal skin infections (ringworm, jock itch, and athlete’s foot).
Bitter orange peel is also used to improve appetite, and, in surprising contrast, it is also used for weight loss. Other uses for the fruit and peel are upset stomach, nasal congestion, and chronic fatigue syndrome (CFS).
The bitter orange flower and bitter orange oil are used for gastrointestinal (GI) disorders including ulcers in the intestine, constipation, diarrhea, blood in feces, drooping (prolapsed) anus or rectum, and intestinal gas. These parts of the bitter orange plant are also used for regulating fat levels in the blood, lowering blood sugar in people with diabetes, stimulating the heart and circulation, “blood purification,” disorders of liver and gallbladder, kidney and bladder diseases, and as a sedative for sleep disorders.
Bitter orange oils, extracts, and supplements are used by alternative practitioners for a variety of health purposes, including:
- Weight loss
- Fungal skin infections
- Athletic performance
- High blood pressure
In addition, bitter orange is believed by some to treat angina, allergies, insomnia, nasal congestion, nerve pain, poor appetite, and liver and gallbladder problems.
Many of the benefits are attributed to a compound in bitter orange known as synephrine. Synephrine has a similar chemical composition to ephedra (a substance used for performance enhancement) as well as similar stimulant and thermogenic (heat-generating) properties.
Despite the presumed benefits, there remains little evidence that bitter orange can effectively treat many of these metabolic or infectious disorders.
In recent years, a small number of adverse events have been reported for people taking bitter orange. The events are primarily cardiac problems such as those reported with ephedra, including at least two deaths in Canada. For this reason, the US National Center for Complementary and Alternative Medicine has concluded: “There is currently little evidence that bitter orange is safer to use than ephedra.”
Bitter orange is LIKELY SAFE for children and adults when taken in the amounts found in food. Bitter orange essential oil is POSSIBLY SAFE when applied to the skin or inhaled as aromatherapy.
But bitter orange is POSSIBLY UNSAFE when taken as a supplement for a medical purpose such as weight loss. Bitter orange, taken by itself or with stimulants such as caffeine or caffeine-containing herbs, might increase the risk for high blood pressure, fainting, heart attack, stroke, and other severe side effects.
There are reports that bitter orange can trigger headaches, including migraine and cluster headaches, in some people.
Bitter orange can cause sensitivity to the sun. Wear sunblock outside, especially if you are light-skinned.
The correct dosage of any supplement requires a comprehensive analysis of many factors including your age, sex, health conditions, DNA, and lifestyle.
For obesity or weight loss, bitter orange extract (975 mg) in combination with St. John’s wort (900 mg) and caffeine (528 mg) per day has been used. Another specific combination product (Charge, Labrada) containing bitter orange 150 mg, providing nine milligrams of synephrine, plus caffeine and several other ingredients taken twice daily has also been used, however, this product has not been shown to reduce weight. Bitter orange extracts commonly contain from 1.5% to 6% synephrine. For the topical treatment of fungal skin infections, pure oil of bitter orange has been applied once daily for one to three weeks.
For medicinal purposes, bitter orange is typically sold as a tablet, gelcap, or extract. Herbalists will often sell powdered bitter orange peel to mix in topical creams and ointments. Zhishi is also available in powdered form.
There are no standardized prescribing recommendations for bitter orange. As a rule of thumb, if you decide to use a bitter orange supplement, do not exceed the recommended dose on the product label.