star anise

Star anise is the seed pod of the fruit of Illicium verum, a small evergreen tree native to China. Star anise seeds are used as a spice in food in Chinese and Indian cuisine. The ground powder of dried star anise is used to make a tea that is used for medicinal purposes. Star anise essential oil is used orally and for inhalation. Star anise is used for many ailments including respiratory ailments, flu, and gastrointestinal conditions, however, there are no adequate studies to support its efficacy in most of its uses.

Studies indicate star anise may have antioxidant, anti-inflammatory, antimicrobial, anti-cancer, antispasmodic, and sedative properties. The pharmacological effects of star anise are believed to be from its bioactive components including sesquiterpenes, phenylpropanoids, lignans, and flavonoids. In addition, star anise contains many nutrients including protein, carbohydrate, fat, fiber, and minerals such as calcium, sodium, potassium, and iron.

Star anise is the source of shikimic acid, a substance used to produce oseltamivir, an antiviral medication for influenza A and B, but star anise itself has not been proven to have any antiviral properties. Star anise may be contaminated with Japanese star anise which looks similar but is toxic. In 2003, the US FDA warned consumers not to consume teas brewed from star anise due to reports of serious side effects.

The suggested uses of star anise include:

• Influenza
• Swine flu
• Avian flu
• Respiratory infection
• Respiratory inflammation
• Cough
• Bronchitis
• Gastrointestinal upset
• Infant colic
• Gas (flatulence)
• Loss of appetite

• Avoid giving star anise to children, it can be toxic to young children and cause neurological and gastrointestinal symptoms.
• Illicium verum or Chinese star anise may sometimes be contaminated or adulterated with Japanese star anise (Illicium anisatum), which is similar in appearance but highly toxic. Japanese star anise can cause nausea, hallucinations, and epilepsy.
• Repeated use of star anise may result in the development of sensitivity.

There are no known major side effects of star anise. Star anise can cause gastrointestinal and neurological side effects in babies younger than 3 months. Ingestion of 1 to 5 ml of anise oil may cause side effects that include:

• Nausea
• Vomiting
• Seizures
• Fluid in lungs (pulmonary edema)

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

There isn’t enough reliable information to know what might be an appropriate dose of star anise. There are no standard, established, safe and effective doses for star anise.

Typical Dosing Guideline

Tea

• 1 cup orally once daily
• 0.5-1 g ground seed boiled in 150 mL water for 120 minutes, strain

Ground

• 3 g/day oral

Essential Oil

• 300 mg/day oral

Inhaled

• Products with 5-10% of essential oil have been inhaled

Overdose

• Star anise used to flavor foods is unlikely to result in an overdose. Overdose of anise oil or tea may cause nausea, vomiting, seizures, and pulmonary edema. Overdose may be treated with symptomatic and supportive measures.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Star anise has no listed severe, serious, moderate, or mild interactions with other drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider about all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or healthcare provider if you have any questions about the medication.

• Star anise consumed as a spice in food is likely acceptable. Avoid taking star anise tea if you are pregnant or breastfeeding.
• Avoid taking any herbal product including star anise, without first checking with your healthcare provider, if you are pregnant or breastfeeding.

• Star anise is possibly safe for most adults in amounts normally used as spice in food, but likely unsafe in other forms. Exercise caution.
• Use star anise exactly as per label instructions. Natural products are not necessarily safe always and following suggested dosing is important.
• Check with your healthcare provider before taking any dietary supplement, including star anise, particularly if you have any health conditions or taking regular medications.
• Herbal products often contain many ingredients. Check labels for the components in the star anise product you choose.
• Star anise teas may be contaminated with Japanese star anise which is poisonous. Exercise caution and purchase star anise products made by well-known and reputed manufacturers.
• Star anise is marketed as an herbal supplement and is not regulated by the FDA. Products may differ in formulations and strengths, and labels may not always match contents; exercise caution in choosing your product.
• Store star anise safely out of reach of children.
• In case of overdose, seek medical help or contact Poison Control.