Star anise tea is a warm, licorice-flavored brew traditionally used to support digestion, fight infections, and ease respiratory symptoms. The dried star-shaped pods of Chinese star anise (Illicium verum) contain a potent essential oil made up of roughly 81% trans-anethole, the compound responsible for most of the spice’s flavor and therapeutic properties. Here’s what the evidence says about the specific benefits of drinking it.
Digestive and Bloating Relief
Star anise has been used for centuries across Asian and Middle Eastern traditions as a digestive aid, and anethole is the reason why. This compound relaxes smooth muscle in the digestive tract, which can help ease cramping, reduce gas, and relieve the uncomfortable pressure of bloating. If you’ve ever sipped fennel tea for an upset stomach, star anise works through a similar mechanism, since fennel also contains high levels of anethole.
Drinking a cup after a heavy meal is one of the most common traditional uses. The warm liquid itself helps stimulate digestion, while the anethole works to calm spasms in the intestines that contribute to that overly full, gassy feeling.
Antimicrobial Properties
Star anise has demonstrated broad antimicrobial activity against bacteria, yeast, and fungal strains. Isolated anethole tested against these pathogens performs comparably to standardized antimicrobial agents, which helps explain why the spice has long been used as a natural remedy during colds and infections. In tea form, these compounds may help support your body’s defense against common oral and throat pathogens, making it a reasonable choice when you’re fighting a sore throat or mild upper respiratory infection.
The Tamiflu Connection
One of star anise’s most surprising claims to fame is its role in producing the antiviral drug oseltamivir, commonly known as Tamiflu. Star anise is one of the primary natural sources of shikimic acid, the starting material used in the only current industrial route to synthesize the drug. That process converts shikimic acid into oseltamivir over about 12 steps, with an overall yield of roughly 35%.
This doesn’t mean drinking star anise tea will treat the flu the way Tamiflu does. Shikimic acid itself isn’t an antiviral. It requires extensive chemical transformation to become one. But the connection does underscore that star anise contains biologically significant compounds with real pharmaceutical relevance.
Mild Estrogenic Effects
Anethole-containing plants have measurable estrogenic activity, producing roughly 30 to 50% of the maximal estrogen response in lab assays. This is why star anise has traditionally been used to ease menstrual cramps and menopausal symptoms like hot flashes. The estrogenic effect isn’t from anethole alone. Other compounds in the plant appear to contribute as well, though researchers haven’t fully identified all of them.
For people experiencing mild menopausal discomfort, regular consumption of star anise tea is one of the more accessible herbal options. The effect is modest compared to pharmaceutical hormone therapy, but that’s also what makes it relatively low-risk for occasional use.
Blood Sugar Support
Animal research has shown that star anise extract can lower blood glucose levels in both normal and diabetic subjects. In one study using diabetic rats, blood sugar dropped within 6 hours of administration, and after 7 days of treatment, glucose levels remained lower while the extract also showed antioxidant activity. These results are promising but still preliminary. Human trials are limited, so star anise tea shouldn’t replace any diabetes management plan, but it may offer a small complementary benefit for people watching their blood sugar.
How to Brew Star Anise Tea
The simplest preparation uses about one teaspoon of dried star anise seeds (or one to two whole pods, lightly crushed) per cup of water. Bring the water to a boil, remove it from heat, then add the star anise. Cover and let it steep for 10 minutes before straining. Crushing the pods slightly before steeping helps release more of the essential oils into the water. You can drink up to three cups per day, though most people find one or two cups sufficient. If you’re using it for a specific purpose like digestive relief, drinking it consistently for up to two weeks is a reasonable timeframe.
Star anise pairs well with other warming spices. Adding a slice of ginger, a cinnamon stick, or a few cloves creates a richer tea with overlapping benefits for digestion and comfort during cold weather.
Chinese vs. Japanese Star Anise: A Critical Safety Difference
There is one important safety issue worth knowing about. Chinese star anise (Illicium verum) is the edible species used in cooking and tea. Japanese star anise (Illicium anisatum) looks nearly identical but contains anisatin, a potent neurotoxin that can cause seizures, hallucinations, and nausea. The anisatin signal in Japanese star anise is typically over 1,000 times higher than in the Chinese variety.
Contamination has been documented in commercially sold products, particularly loose star anise and pre-packaged teas. To minimize risk, buy from reputable spice vendors who specifically label their product as Chinese star anise or Illicium verum. Avoid purchasing from sources where the species isn’t clearly identified. If you notice any unusual neurological symptoms after drinking star anise tea, such as dizziness, visual disturbances, or tremors, stop consuming it immediately.