Use: Pharmacological actions for C. aurantium include antispasmodic, sedative, demulcent, digestive, tonic, and vascular stimulant; as an anti-inflammatory, antibacterial, and antifungal agent; and for reducing cholesterol. Clinical data are limited. Most medical literature focuses on the plant’s safety and efficacy in OTC weight loss supplement formulations, with studies using small sample sizes and often focusing on combination products. Therefore, no recommendations for any indication can be made.
Dosing: Follow manufacturer’s dosage guidelines because synephrine content may vary in supplement formulations. Contraindications: Because of potentially additive effects, avoid synephrine use in patients with hypertension, tachyarrhythmia, hyperthyroidism, or narrow-angle glaucoma.
Pregnancy/Lactation: Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.
Interactions: C. aurantium inhibits intestinal CYP3A4 and intestinal efflux in the small intestine and may interact with numerous drugs, including amiodarone, anxiolytics, antidepressants, antiviral agents, calcium channel blockers, dextromethorphan, GI prokinetic agents, vasoconstrictors, and weight loss formulas.
Adverse Reactions: Bitter orange may cause photosensitization, particularly in people with fair skin. There are numerous case reports of adverse cardiac reactions associated with C. aurantium extract use.
Toxicology: Bitter orange is considered generally recognized as safe (GRAS) by the US Food and Drug Administration (FDA) when consumed in amounts found in foods. Medical literature primarily documents cardiovascular toxicity, especially due to the stimulant amines synephrine, octopamine, and N-methyltyramine, which may cause vasoconstriction as well as increased heart rate and blood pressure.