Close-up of water drops on an orange
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Orange peel extract is derived from what is known as the Seville orange, bitter orange or Citrus aurantium. Orange peel has long been used in traditional Chinese medicine and in the Amazon as an herbal remedy for indigestion and nausea, according to the National Center for Complementary and Alternative Medicine. Today, it also is used for appetite suppression in weight loss programs, nasal congestion and fungal skin infections. Orange peel extract should be used with caution, however, for side effects are possible.

General Stimulant Effects

Orange peel contains synephrine, which produces stimulant effects similar to those of ephedra, the substance that the Food and Drug Administration banned in weight loss products in 2004. Ephedra was associated with increased risks of stroke and heart attack in customers. Indeed, several of these diet products now contain concentrated extracts of Citrus aurantium for its stimulant properties in the place of ephedra, reports the National Center for Complementary and Alternative Medicine. Some general stimulant effects you may experience from synephrine are feeling nervous or restless as well as trouble sleeping. If you take a supplement that also contains caffeine, be aware that the stimulant effects may be magnified. Since the extent of orange peel side effects are unknown at this time, speak with your doctor first before trying this substance.

Cardiovascular Risks

Synephrine is associated with cardiovascular system effects that include high blood pressure or hypertension, arrhythmias, that is, irregular heart rhythms, a fast heart rate or tachycardia, and fainting, heart palpitations as well as chest pain, states EMedTv.com. It is imperative that you avoid products containing orange peel extract until you have discussed this with your doctor -- especially if you have a personal or family history of heart disease.

Weakness and Vision Problems

Another potential side effect of orange peel extract is the sensation of significant weakness or paralysis on one side of your body, notes EMedTv.com. This may or may not be accompanied by vision problems. For example, you may find that your vision has become blurred and that you cannot focus clearly. Also, orange theoretically may worsen narrow-angle glaucoma, warns Wellness.com. Finally, seizures also have been associated with orange peel extract, according to EMedTv.com. Get immediate medical care if these symptoms occur.

Headaches and Hyperthyroidism

Synephrine may produce migraine or cluster headaches, notes Wellness.com. Additionally, those with hyperthyroidism should be careful about taking supplements containing orange peel extract, because this substance may aggravate this thyroid condition.

Ischemic Colitis

Ischemic colitis is a serious potential side effect of orange peel, states EMedTV.com. This gastrointestinal condition has the following symptoms: abdominal cramping or pain, severe diarrhea with bloody stools, vomiting, and fever. If you begin to experience any or several of these symptoms, contact your health provider immediately or get emergency medical attention.