This is not medical advice
HelperTea summarizes published research and traditional use. It does not diagnose, treat, or prevent any condition, and is no substitute for a clinician who knows your history.
No content here is written or reviewed by a doctor, pharmacist, herbalist, or any other healthcare professional. Never delay care, and never stop a prescribed treatment, because of something you read here.
Herbs are drugs
A plant with a measurable effect on the body can also interfere with medication, raise or lower drug levels, or damage organs on its own. Herbal and dietary supplements now account for roughly a fifth of cases reported to the US Drug-Induced Liver Injury Network.
Ask a pharmacist or doctor before taking any herb if you take prescription medication, are pregnant or breastfeeding, are giving it to a child, have liver or kidney disease, or face surgery.
In an emergency
For a suspected medical emergency — chest pain, trouble breathing, a severe allergic reaction, seizures, confusion, or suspected poisoning — call your local emergency number (911 in the United States) immediately. In the US, Poison Control is 1-800-222-1222 or poisonhelp.org. Do not look it up here first.
Herbs on this site that need extra care
- Senna — a stimulant laxative. MedlinePlus advises against use beyond one week without talking to a doctor; continued use can cause laxative dependence and loss of normal bowel activity. Not for undiagnosed abdominal pain. Seek care for rectal bleeding.
- Licorice root — its glycyrrhizin can cause serious harm, including irregular heartbeat and cardiac arrest, especially in large amounts or over the long term (NCCIH). Even small amounts have been linked to severe effects in people who consume a lot of salt, and in those with high blood pressure or heart or kidney conditions. Large amounts in pregnancy are unsafe and are linked to earlier delivery. Interactions with corticosteroids have been reported.
- Valerian — sedating; do not combine it with alcohol or sedatives. Stopping abruptly after chronic use has caused anxiety, irritability, and insomnia. Liver injury is rarely reported, mostly with multi-herb products. Safety in pregnancy and breastfeeding is unknown.
- Feverfew — do not take it while pregnant, as it may affect uterine contractions. People sensitive to ragweed and related plants may react to it. It may slow blood clotting; stop it at least two weeks before surgery. Chewing fresh leaves can cause mouth sores.
- Eucalyptus — eucalyptus oil is poisonous when swallowed. Ingestion has caused vomiting, drowsiness, seizures, coma, and death, and young children are especially vulnerable. Keep it out of reach; never take it internally.
- Elderberry — raw or unripe berries, and the leaves, stems, and bark, contain cyanide-producing compounds that cause nausea, vomiting, and severe diarrhea. Cooking destroys them. Never eat or juice raw elderberry.
Pregnancy, breastfeeding, and children
For most herbs here, safety in pregnancy, breastfeeding, and childhood has never been studied. Unknown is not the same as safe. Ask a clinician.
No professional relationship
Reading this site, or emailing us, creates no doctor-patient relationship. We cannot answer personal medical questions; our contact page explains why. Use of this site is at your own risk. See also our terms of use.
Sources for this page
NCCIH (nccih.nih.gov), MedlinePlus (medlineplus.gov), and PubMed, including Sitaraman R, Rao G. Cureus. 2019;11(9):e5734 (PMID: 31723495) on eucalyptus oil poisoning and Halegoua-DeMarzio D, Navarro V. Liver Int. 2025;45(3):e16071 (PMID: 39136211) on herb-induced liver injury.
Last reviewed and updated . HelperTea is written by an enthusiast, not a clinician, and is not medically reviewed. How we research and rate evidence. Found an error? Tell us — safety corrections get priority.