Star Anise
OTHER NAME(S): Chinese star anise, Illicium verum, star anise
Overview
Star anise is a tree called Illicium verum. The dried, star-shaped fruits of the tree are used as a spice and are also found in teas and dietary supplements. Although star anise may be used for many different reasons, its benefits are not well defined. Common side effects may include nausea, vomiting, and upset stomach. Serious side effects, such as seizures, are rare, but are more likely in infants and young children. Be cautious when purchasing star anise products, which may contain a similar plant that can be toxic. Before using star anise, make sure to tell your health care provider about any health conditions you have or medicines you are taking.
Uses
What is star anise used for?
Star anise (Illicium verum) is sometimes used for many different reasons, although its benefits are not well defined. Some common reasons that people use star anise include the following.
- Cough
- Gas (flatulence)
- To improve oral health
- To improve gut and digestive health
Note: The FDA has not reviewed star anise for safety and effectiveness. Learn more about dietary supplements here.
How does star anise work (mechanism of action)?
Star anise, or Chinese star anise, is a tree called Illicium verum. It is commonly used as a spice, in teas, and as a dietary supplement. Products that contain star anise are made from the dried, star-shaped fruit of the plant. The oil of this fruit, known as star anise oil, is sometimes used to flavor foods and drinks. It is important not to confuse star anise with another plant called Japanese star anise (Illicium anisatum). This other plant has a very similar star-shaped fruit that is toxic and should not be used for any purpose.
Star anise contains a chemical called anethole, which gives it a strong, licorice-like flavor. Anethole is sometimes used to make candies and other foods taste like licorice. It is also found in other plants that taste like licorice, including anise (Pimpinella anisum) and fennel (Foeniculum vulgare). But anethole is not the chemical that gives licorice (Glycyrrhiza glabra) its distinctive flavor. Licorice contains other chemicals, such as glycyrrhizin, that have different effects in the body.
Star anise contains many different chemicals that may have effects in the body, including anethole and flavonoids. These chemicals may act as antioxidants and reduce swelling (inflammation). These effects are thought to help relieve gas, cough, and other gut problems. But the benefits of star anise for any use are poorly studied and not well defined.
Some of the chemicals in star anise may help kill bacteria that live in the mouth. But it is not clear if star anise tea or mouthwash can kill enough bacteria to have a meaningful effect on the health of the mouth or gut.
Herbal products, such as star anise, naturally contain many different chemicals. The amounts of each chemical in a specific star anise product may vary. Some, none, or all of these chemicals may have effects on the body. These effects may change depending on how much of each chemical is found in the product you are using.
How should I store star anise?
You should store star anise according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.
Side Effects
What are the most common side effects of star anise?
The most common side effects of star anise are listed below. These side effects may vary depending on the dose you are taking or the specific product you are using. Tell your health care provider if you have any of these side effects that bother you.
- Nausea or vomiting
- Upset stomach
There may be other side effects of star anise that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of star anise?
While less common, the most serious side effects of star anise are described below, along with what to do if they happen.
Severe Allergic Reactions. Star anise may cause allergic reactions, which can be serious. Stop using star anise and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble swallowing or throat tightness
- Itching or skin rash
- Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
- Nausea or vomiting
- Dizziness, feeling lightheaded, or fainting
- Stomach cramps
- Joint pain
Seizures. Some people who have taken star anise have reported having seizures. This risk may be higher in infants and young children or if it is taken at high doses. There are many different types of seizures, and some of them are not easy to recognize. Stop taking star anise and call your health care provider if you have any of the following signs that a seizure is happening or could happen.
- Muscle twitching, jerking, spasms, tremors, or other uncontrolled movements
- Stiffening of your arms and legs
- Feeling anxious, nervous, confused, or a sense of dread
- Feeling dizzy or lightheaded
- Falling or losing consciousness
Skin and Lip Reactions. Star anise can cause reactions on the skin and lips, such as rashes, blisters, and peeling. This risk seems to be higher in people who use oral hygiene products that contain star anise, such as toothpaste or mouthwash. In some people, these skin reactions may be caused by an allergy (contact dermatitis) to a chemical in star anise called anethole. Stop using star anise and contact your health care provider right away if you have a reaction on your skin or lips.
Precautions
Who should not use star anise?
Allergies to Ingredients. People who are allergic to any of the following should not use star anise.
- Anethole
- Chinese star anise
- Illicium verum
- Star anise
- Any of the ingredients in the specific product
Your pharmacist can tell you all of the ingredients in the specific star anise products they stock.
What should I know about star anise before using it?
Star anise cannot be marketed to treat or cure a disease.
Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.
Keep star anise out of the reach of children. Infants and young children are at greater risk of serious side effects from star anise, including seizures and severe vomiting. Talk to your health care provider about the risks of star anise teas or supplements in infants and young children.
Herbal products, such as star anise, naturally contain many different chemicals. The amount of each chemical in a specific star anise product can change for many reasons, including the area where the tree was grown, the weather during growth, the time of year it was harvested, and the way that the fruit was processed after harvest. If you switch to a new bottle or a different brand, you may not have the same effects or side effects because of this variability. Talk to your health care provider if you have questions or concerns.
Star anise is available as a dietary supplement and in many different forms, including liquid extracts, dried ground powder in capsules, and dried fruit to be added to tea or used as a spice. Star anise oil is also used to flavor foods. Each of these forms may contain different amounts of the chemicals that are naturally found in the fruit.
Many star anise teas have been found to contain Japanese star anise (Illicium anisatum), a tree that has similar, star-shaped fruits. But the fruits from Japanese star anise are toxic and can cause serious health problems. The FDA has released warnings about the risks of drinking star anise tea. Since star anise and Japanese star anise look very similar, it may not be possible to confirm that the product you are purchasing is safe.
The FDA has not tested star anise products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.
What should I tell my health care provider before using star anise?
Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if star anise is right for you.
In particular, make sure that you discuss any of the following.
Allergies to Certain Plants.If you have an allergy to other plants that contain anethole, such as anise or fennel, you may be more likely to have an allergic reaction to star anise. You may also be more likely to have an allergic reaction to star anise if you have an allergy to birch, celery, carrots, or mugwort. Speak with your health care provider before using star anise if you have an allergy to any of these plants.
Other Current and Past Health Conditions.Tell your health care provider if you have any of the following.
- Kidney problems
- Liver problems
- Seizures
Pregnancy. It is not known if or how star anise could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.
Breastfeeding. It is not known if star anise passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.
Interactions
Does star anise interact with foods or drinks?
There are no known interactions between star anise and foods or drinks.
It is unknown if drinking alcohol will affect star anise.
Does star anise interact with medicines (drug interactions)?
Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
The interactions between star anise and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with star anise is incomplete. Always check with your health care provider before using star anise with any medicines.
Dosing
What should I do if I accidentally use too much star anise?
If you or someone else has used too much star anise, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
Star anise is found in a wide range of products, including teas, flavoring oils, spices, and dietary supplements. Read the product label closely and speak with a health care provider about how to use star anise safely. Do not use double or extra doses, even if you miss a dose.
References
- BioMed Research International: “Crossover analysis of the astringent, antimicrobial, and anti-inflammatory effects of illicium verum/star anise in the oral cavity.”
- DermNet: “Contact reactions to toothpaste and other oral hygiene products.”
- Gardner, Z; McGuffin, M. Botanical Safety Handbook (Second Edition), American Herbal Products Association, 2013.
- FDA: “FDA Issues Advisory on “Teas”: Teas Made from Star Anise Were Associated With Illnesses Including Seizures”
- Khan, I; Abourashed, E. Leung’s Encyclopedia of Common Natural Ingredients (Third Edition), Wiley, 2010.
- Molecules: “A comprehensive review of the pharmacology, chemistry, traditional uses and quality control of star anise (Illicium verum Hook. F.): an aromatic medicinal plant.”
- Pediatrics: “Neurotoxicities in infants seen with the consumption of star anise tea.”
- Revista Española de Enfermedades Digestivas: “Liver failure secondary to poisoning by a homemade product made of star and green anise in a 4-month-old infant.”