Tansy Health Benefits: What It Can Do and When to Avoid It

Tansy (Tanacetum vulgare) pops up in old herbal books as a fix for digestion, worm infections, and even to keep insects away. Sounds promising, right? Before you try it, you should know what it does, how people use it today, and—critically—when it can be dangerous.

What tansy can help with

People use tansy in a few practical ways: as a mild digestive aid, a traditional vermifuge (to help expel intestinal worms), a topical anti-itch or insect-repellent, and sometimes for minor inflammation. Lab studies show extracts can kill certain bacteria and fungi in test tubes, and researchers have identified compounds such as thujone and camphor that likely drive these effects. That makes tansy useful as an outdoor insect spray or a short-term topical for bug bites—diluted, not raw.

Homemade tansy tea is still made by some for bloating or stomach cramps. If you see tinctures or dried-leaf products online, they’re usually aimed at occasional digestive support or as a pantry herb for pest control. People also use small amounts in sachets to deter moths and other insects.

Risks, safety and practical tips

Tansy contains thujone, which can harm the nervous system and the liver in higher doses. That means: do not use tansy internally if you are pregnant, breastfeeding, have liver problems, or take certain medications. Even small doses can trigger uterine contractions, so avoid it in pregnancy. Essential oil is highly concentrated and can cause seizures or severe reactions if swallowed—never take tansy oil internally.

Topical use should be cautious. Some people get skin irritation or allergic reactions when using tansy directly on the skin. Always do a patch test: apply a diluted amount to a small area and wait 24 hours. If irritation appears, stop.

Practical tips: if you want to try tansy, use low-dose preparations from a reputable herbal supplier or consult a trained herbalist. For pest control, make a diluted spray from fresh or dried leaves and keep it away from pets and food prep areas. For digestive issues, try gentler, better-studied herbs first—peppermint or ginger have safer records and clearer dosing.

Quick checklist:

• Not for pregnant or breastfeeding people.
• Do not ingest tansy essential oil.
• Start with tiny doses if using any internal form, and only under guidance.
• Test topically on a small skin area first.
• Prefer commercially prepared products with clear dosing and safety info.

Tansy can offer helpful properties, especially for topical and insect-repellent uses, but it carries real risks when swallowed or overused. If you're curious about trying it for health reasons, talk to a healthcare provider or herbalist who knows the herb and your medical history. That way you get the benefits without the avoidable dangers.