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Milk Thistle

Medically reviewed by Last updated on Sep 23, 2021.

What are other common names?

  • Carduus marianus
  • Fructus cardui mariae
  • Fructus silybi mariae
  • Mariana mariana
  • Silybum marianum
  • Blessed Milk Thistle
  • Bull Thistle
  • Chardon-Marie
  • Holy Thistle
  • Lady's Milk
  • Lady's Thistle
  • Marian Thistle
  • Mary Thistle
  • Mild Marian Thistle
  • Our Lady's Thistle
  • Pternix
  • Shui Fei Ji
  • Silberdistil
  • Silibinin
  • Silibum
  • Silybe
  • Silybin
  • Silybon
  • Silybum
  • Silymarin
  • Silymarine
  • St Mary Thistle
  • St Marys Thistle
  • St. Mary's Thistle
  • Thistle
  • Thistle of the Blessed Virgin

What is this product used for?

Milk thistle is used by some people to help with liver problems. Others use it to help prevent harm to the liver. Some people with diabetes will take it to help lower blood sugar.

What are the precautions when taking this product?

  • Always check with your doctor before you use a natural product. Some products may not mix well with drugs or other natural products.

  • Do not use this product if you are pregnant or plan to become pregnant soon. Use birth control you can trust while taking this product.

  • Do not use this product if you are breastfeeding.

  • This product may interfere with some lab tests. Be sure to talk with your doctor about this and all drugs you are taking.

  • Take extra care if you are allergic to pollens or plants like ragweed, daisy, aster, marigolds, or chrysanthemums.

  • Take extra care and check with your doctor if you have:

    • Diabetes

    • Cancer

    • Problems like endometriosis or fibroids

  • Keep hard candies, glucose tablets, liquid glucose, or juice on hand for low blood sugar.

What should I watch for?

  • Upset stomach

  • Increased gas and bloating

  • Heartburn

  • Headache

  • Not hungry

  • Rash

When do I need to call the doctor?

  • Signs of a very bad reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat. Go to the ER right away.

  • Signs of low blood sugar. These include hunger, dizziness, shaking, a fast heartbeat, confusion, or sweating.

  • Signs of liver problems. These include upset stomach or throwing up, belly pain, feeling tired, dark urine, yellow skin or eyes, not hungry.

  • Very bad throwing up

  • Very bad loose stools

Where can I learn more?

National Center for Complementary and Alternative Medicine

Last Reviewed Date


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