A research review of human and relevant scientific studies on Illicium verum.
Last reviewed: August 2026
🔬 Research Summary
- Digestive/traditional use: Star anise has traditional use in digestive preparations, but controlled human clinical evidence for tea is limited.
- Antimicrobial activity: Laboratory studies show antimicrobial effects of star-anise compounds and essential oil.
- Antioxidant activity: In-vitro studies demonstrate antioxidant activity associated with phenolic compounds and anethole.
- Metabolic and inflammatory research: Animal and laboratory studies have investigated glucose, lipids and inflammatory pathways.
- Safety and authentication: Correct botanical identification is essential because Japanese star anise (Illicium anisatum) can be toxic and has been implicated in poisoning.
The sections below summarize the principal health areas investigated in the literature. Evidence strength is not uniform, and studies using extracts, oils, capsules or combination products are identified conceptually rather than treated as interchangeable with tea.
Digestive/traditional use
What researchers found
Star anise has traditional use in digestive preparations, but controlled human clinical evidence for tea is limited.
What remains uncertain
Study results, doses, preparations and participant populations differ. Where the evidence is based mainly on extracts, oils, capsules, combinations, laboratory models or people with a specific condition, that limitation should be considered when interpreting the findings for a normal cup of tea.
Antimicrobial activity
What researchers found
Laboratory studies show antimicrobial effects of star-anise compounds and essential oil.
What remains uncertain
Study results, doses, preparations and participant populations differ. Where the evidence is based mainly on extracts, oils, capsules, combinations, laboratory models or people with a specific condition, that limitation should be considered when interpreting the findings for a normal cup of tea.
Antioxidant activity
What researchers found
In-vitro studies demonstrate antioxidant activity associated with phenolic compounds and anethole.
What remains uncertain
Study results, doses, preparations and participant populations differ. Where the evidence is based mainly on extracts, oils, capsules, combinations, laboratory models or people with a specific condition, that limitation should be considered when interpreting the findings for a normal cup of tea.
Metabolic and inflammatory research
What researchers found
Animal and laboratory studies have investigated glucose, lipids and inflammatory pathways.
What remains uncertain
Study results, doses, preparations and participant populations differ. Where the evidence is based mainly on extracts, oils, capsules, combinations, laboratory models or people with a specific condition, that limitation should be considered when interpreting the findings for a normal cup of tea.
Safety and authentication
What researchers found
Correct botanical identification is essential because Japanese star anise (Illicium anisatum) can be toxic and has been implicated in poisoning.
What remains uncertain
Study results, doses, preparations and participant populations differ. Where the evidence is based mainly on extracts, oils, capsules, combinations, laboratory models or people with a specific condition, that limitation should be considered when interpreting the findings for a normal cup of tea.
Overall Assessment
Star anise has substantial phytochemical and laboratory research but limited human clinical evidence for tea. Safety and botanical authentication are especially important for this ingredient.
References
- Wang GW, Hu WT, Huang BK, Qin LP. Illicium verum: a review on its botany, traditional use, chemistry and pharmacology. J Ethnopharmacol. 2011;136(1):10-20. PMID: 21549817. doi:10.1016/j.jep.2011.04.051.
- Zou Q, et al. A Comprehensive Review of the Pharmacology, Chemistry, Traditional Uses and Quality Control of Star Anise (Illicium verum Hook. F.): An Aromatic Medicinal Plant. Molecules. 2023;28(21):7378. PMID: 37959797. doi:10.3390/molecules28217378.
- Madden GR, Schmitz KH, Fullerton K. A case of infantile star anise toxicity. Pediatr Emerg Care. 2012;28(3):284-285. PMID: 22391927. doi:10.1097/PEC.0b013e3182495ba7.
Reference note: References were selected to represent the principal human clinical and systematic-review evidence discussed in this article. Where direct tea-infusion evidence is limited, the article explicitly identifies that limitation.
Publication version: August 2026
These statements have not been evaluated by Medsafe. This tea is not intended to diagnose, treat, cure, or prevent any disease. If you are pregnant, breastfeeding, or managing a health condition, check with your healthcare provider before making it a regular habit.
