Tansy Supplement: Uses, Safety, and What to Know

Tansy supplements pop up online as a cure for digestion problems, parasites, and menstrual cramps. Before you try one, know that tansy (Tanacetum vulgare) is a strong herb with risks as well as uses.

What it is and how people use it: Tansy is a flowering plant that Europeans used for centuries. Traditional uses include easing gas, helping clear intestinal worms, and reducing menstrual pain. Modern supplements come as teas, capsules, tinctures, and essential oils.

Practical uses and evidence

Lab tests show tansy compounds can fight some bacteria and parasites, but human studies are few. That means there’s limited proof it works the way old herbal books claim. If you’re looking for a mild digestive aid, gentler options like peppermint or fennel have more reliable evidence. Using tansy for parasites or serious conditions should only follow advice from a qualified clinician.

Forms and dosing: Tansy is sold as dried herb for tea, alcohol-based tinctures, capsules, and essential oil. There’s no standard dosing. Labels vary and many products don’t state thujone levels—the compound linked to toxicity. If you try a product, choose the lowest recommended dose, use it short term, and follow the label.

Safety and who should avoid it

Safety: Tansy contains thujone, which can cause nausea, dizziness, convulsions, and even organ damage at high doses. Essential oil is especially concentrated and should never be swallowed. Avoid tansy if you are pregnant or breastfeeding—historic use links it to uterine contractions and risks to the fetus. People with epilepsy, liver disease, or those taking medications that affect the nervous system should stay away. It may also cause skin irritation in sensitive people.

Interactions and precautions: Tansy may interact with anti-seizure drugs, sedatives, and possibly blood thinners. Because labs don’t always check thujone, treat tansy like a strong medicine: tell your doctor if you plan to use it, stop before surgery, and keep it away from children.

Buying tips: Buy from brands that post testing results or use third-party labs. Avoid internal use of essential oil. If a seller promises miracle cures, be skeptical. Ask the vendor about thujone content and how long a course should last.

Watch for side effects and what to do: If you start tansy, watch for tremor, confusion, severe nausea, vomiting, or sudden headaches. Stop immediately and seek medical care if you notice these signs. Avoid combining tansy with alcohol or sedating drugs. If you apply product to skin, do a 24-hour patch test on a small area to check for rash. Keep bottles labeled and out of reach. Tell your pharmacist about tansy so they can check for drug interactions and advise safe use and monitor.

Final practical take: Tansy has a long folk history and some lab support, but proof in people is thin and risks are real. For simple belly upset or to help digestion, try safer herbs first. If you still want to try tansy, talk with a healthcare pro, pick a tested product, and use the smallest effective dose for a short time.