Dangers of Milk Thistle

milk thistle plant

A new study from the University of Pittsburgh points to several dangers of milk thistle, particularly for patients with HIV-AIDS and hepatitis C. It's important to keep in mind that the University of Pittsburgh study is but one study, and more are needed to fully understand the potential effects of milk thistle and potential dangers.

Milk Thistle

Milk thistle (Silybum marianum) has been used since the time of Christ as a remedy for liver and gallbladder ailments. The active ingredient taken from the milk thistle plant's seeds is silymarin, and the word is sometimes used interchangeable with milk thistle to refer to the herb. It's often recommended as a detoxification herb and has a long history of use to help the liver detoxify. The many benefits of milk thistle make it a popular herb.

The liver is a large, football shaped organ situated on the right side of the abdomen. It has many functions, including filtering poisons and toxins from the blood. Many people take milk thistle in the belief that it can help the liver detoxify and neutralize toxins more effectively. Milk thistle may also help the liver regenerate its cells.

Dangers of Milk Thistle

For the majority of people, milk thistle poses no immediate dangers. If you choose to take milk thistle, follow the label directions carefully, since the strength and dose of herbs depends upon the quantity and quality of the extract. Check with an herbalist if you have any chronic ailments or take medications, and always tell your doctor if you are taking any herbal supplements.

Drug Interaction Dangers

The University of Pittsburgh study was cited on HCV Advocate, a website focused on information dissemination for patients with hepatitis and HIV. Since many people take milk thistle to combat hepatitis, it's important to understand the possible dangers of milk thistle, especially if you have either disease.

According to the study, the liver's enzymes break down the chemicals of everything we ingest, from food to medication. Milk thistle may slow or reduce the action of the enzymes, which can cause more of a particular medication to circulate.

To better illustrate how this can be a potential danger, assume that Medicine X, prescribed by your doctor, has a dose of one, 500-milligram tablet once a day. That dose depends on your weight, health conditions, and other factors. Before approval by the FDA, numerous studies demonstrating the dose's safety and efficacy must be conducted and submitted, so your doctor is reasonably sure that this dose will work and that it won't harm you; your body is likely to metabolize and excrete it within a certain time period.

Now assume that while taking Medicine X, you also take milk thistle. If the enzymes needed to break down Medicine X are reduced by the milk thistle, more than the typical amount of Medicine X remains in the bloodstream because there are insufficient enzymes to break it down. You take another tablet of Medicine X on day two, assuming that everything is fine, but now your body has significantly more of Medicine X than the prescribed dose, even though you took the 500 milligram tablet, just as your doctor told you to do. If this goes on for several days, you could have substantially more of Medicine X circulating in your body than you bargained for, leading to even more of an overload on the liver.

Drugs that Can Interact with Milk Thistle

There's a long list of pharmaceutical drugs that may interact with milk thistle. If you're taking any of these, talk to your doctor or a naturopathic doctor before taking milk thistle. Be sure to seek help from a qualified medical professional who can evaluate your condition, medications and health status; no article can substitute for this. Medications that may interact with milk thistle include:

  • Methadone
  • Antidepressants, including SSRI medications (including the herb St. John's Wort)
  • Antihistamines (Seldane and other brands)
  • Antifungal medications
  • Sedatives and sleeping pills
  • Cholesterol lowering drugs (statin medications)
  • Estrogen
  • Others

Is Milk Thistle Safe?

Given these warnings, is milk thistle safe? Again, the answer depends on various factors. For many people, it is safe to take. For others, it may not be. Talk to a qualified herbalist, naturopathic doctor or a physician for advice. There are some dangers of milk thistle, but for many it is a useful herb.

Dangers of Milk Thistle