Milk Thistle Drug Interactions, Dangers and Contraindications

There are some possible milk thistle drug interactions to be aware of if you are considering taking this supplement.

Milk thistle (Silybum marianum) is a medicinal plant that has been used for more than 2,000 years in traditional herbal medicine. For centuries it was primarily used for the prevention and treatment of conditions related to the liver and/or gallbladder.

Contemporary uses of milk thistle have expanded beyond that of traditional practice. To date, milk thistle has been observed to exhibit anti-inflammatory, antioxidant, anticancer, anti-diabetic, cardioprotective, hepatoprotective and renoprotective actions.

It is now one of the most popular dietary supplements on the market. While it is considered to be relatively safe to use, it may interact with some pharmaceutical drugs and supplements. You should speak to your doctor to determine whether this supplement is appropriate for you to use.

Milk thistle is generally well tolerated by the majority of users. No serious or permanent side effects have been attributed to this herbal extract. It is likely safe even at high doses over long time spans (up to 44 months).

Milk Thistle

Herbal Supplement

Liver Health

Detox

Longevity

How It Works:

• Supports liver health & detox
• Anti-oxidant & anti-inflammatory properties
• Improves insulin sensitivity & cholesterol

Dosage:

Between 140 - 800 mg per day

Safety:

Rated Likely Safe

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Milk Thistle Supplement Overview

The seeds of S. marianum contain the phytochemicals (plant nutrients) believed responsible for the majority of the plant’s beneficial properties. Milk thistle seeds contain a group of flavonolignans collectively called silymarin.

Silymarin is a versatile substance that may cause a number of effects on the human body. It works as an antioxidant, which can neutralize free radicals that cause oxidative damage.

The antioxidant potential of silymarin is believed to be at least ten times that of vitamin E. It has also been observed to significantly increase the availability of superoxide dismutase (SOD), one of the body’s most important antioxidants.

Milk thistle may interact with some medications because of its ability to affect glutathione synthesis. When the liver has higher levels of glutathione, it is better able to detoxify itself and thereby enhance its own performance.

Silymarin supplementation has been observed to elevate rodent glutathione levels by 50 percent. In humans, glutathione levels have been increased by roughly 35 percent.

Milk thistle supplementation helps the liver to clear out hormones, drugs, alcohol, environmental toxins and other harmful agents. Silymarin also encourages protein synthesis in the liver, and suppresses leukotriene production.

This can affect the way that certain drugs are metabolized by the body. For this reason, if you are taking any drugs to address health conditions, it is important to check with your doctor before using milk thistle supplements.

Milk Thistle Drug Interactions

Cytochrome p450 Substrate Medications: Milk thistle may interact with cytochrome p450 substrate medications. By affecting the cytochrome p450 liver enzyme system, this supplement may alter drug metabolism in the liver.

As a result, the levels of these drugs may become elevated or diminished in the blood. This may result in significant changes to the normal effects of the drugs, as well as the prevalence and severity of possible side effects. Serious reactions are possible.

Diabetes Medications:The hypolipidemic (lipid-lowering) and hypoglycemic (blood-sugar-lowering) properties of S. marianum may also lead to drug interactions.

Caution is recommended if using milk thistle in conjunction with diabetic medications, as blood glucose levels may drop below recommended levels. If you are considering milk thistle supplementation, prescription medication dosages may need to be altered.

Drug Interaction Warnings: Other milk thistle drug interactions are possible when the supplement is used in combination with medications that target blood health, lactation, skin health, heart health, stomach/intestinal health, the effects of alcohol consumption, cholesterol control, fertility, hormone balancing, p-glycoprotein modulation, anxiety and/or cancer management.

Always read the manufacturer’s recommendations for usage, and then discuss those recommendations with a doctor or pharmacist before beginning supplementation.

Milk Thistle Supplement Interactions

Silybum marianum may interact with other herbal remedies and dietary supplements.

Caution should be exercised when combining this supplement with other natural compounds that are processed by the liver.

Milk thistle interactions can occur when taken with supplements or herbs that affect blood sugar, liver enzymes and hormone balance. A number of serious side effects are possible and a physician’s approval should be sought prior to combining herbal supplements.

Do not mix S. marianum with the following herbs without first consulting with your your primary healthcare provider:

• Antianxiety, antidiabetic, anticancer, anti-inflammatory, antioxidant, antiretroviral and/or antiviral herbs;
• Supplements for lowering cholesterol;
• Herbal fertility enhancers;
• Calcium and/or iron supplements;
• Supplements used for heart, skin, intestines and/or stomach health;
• Glucuronidated herbal supplements;
• P-glycoprotein modulators;
• N-acetyl cysteine;
• Herbs to address male impotence;
• Hormone balancing supplements.

The United States Food and Drug Administration does not regulate the use of herbal supplements and there are no available guarantees concerning the strength or safety of these medicinal agents.

Determining the optimal dosage for your needs will depend on a number of variables, including health history, therapeutic targets, gender, age, weight, diet, exercise levels and more.

Milk Thistle During Pregnancy and Lactation

Milk thistle is known to promote lactation and is commonly classified as a galactogogue. S. marianum should not be used in conjunction with other galactogogues because it increases the risk of excessive lactation.

Pregnant and nursing women should exercise caution and speak with their OB/GYN about milk thistle supplementation.

Possible Side Effects

The historical use of S. marianum combined with contemporary clinical data suggests the plant is generally well tolerated and likely safe when taken appropriately. Clinical trials have not revealed serious or long-term side effects with supplementation up to five years at recommended doses.

Although serious side effects are rare, the use of milk thistle with interacting drugs or supplements can increase the risk of adverse effects. Consult with your doctor before beginning supplementation to ensure safe use.

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