Milk Thistle Risks

The scientific name for milk thistle is Silybum marianum. Other common names for this plant include bull thistle, holy thistle, milk ipecac, Mary's thistle, royal thistle and wild artichoke. According to the Mayo Clinic, milk thistle has been used to treat liver and gall bladder issues for more than 2,000 years. Milk thistle is also commonly used to increase breast milk supply. The Mayo Clinic reports that there is good scientific evidence for using milk thistle to treat chronic liver disease and cirrhosis. There is less clear evidence for treating hepatitis, cancer, diabetes in patients with cirrhosis, indigestion, liver damage due to drugs or toxins, high cholesterol, Amanita phalloides mushroom poisoning and menopausal symptoms.

Allergic Reactions

• Although generally well tolerated, the Mayo Clinic reports that milk thistle has been known to cause allergic reactions, including skin rashes, in some people with sensitivities to plants in the aster family like ragweed, marigold, daisy and chrysanthemum. Allergic reactions are also common to those who have sensitivities to siliandrin, silydianin, silibinin, silymonin and silychistin, which are chemicals found in milk thistle. Anaphylaxis reactions have been reported in some individuals.

Intestinal Issues

• According to the University of Maryland Medical Center, intestinal issues have been noted in some sensitive individuals. These issues include stomach upset, gas, heartburn, nausea, diarrhea and vomiting. Symptoms abated once the individual stopped taking milk thistle.

Possible Blood Sugar Issues

• Cautions have been issued to diabetics and hypoglycemics. According to the National Center for Complementary and Alternative Medicine (NCCAM), milk thistle may lower blood sugar. The caution also applies to individuals who take medications that lower blood sugar.

Cancer Concerns

• Individuals with hormone-related cancers are also cautioned against using milk thistle because of its possible estrogenic properties, according to the University of Maryland Medical Center. Prostate, breast and uterine cancers may become more aggressive in the presence of estrogen and phytoestrogens.

Drug Interactions

• According to the University of Maryland Medical Center, drug interactions are possible with milk thistle. Patients who are taking anti-psychotics, Halothane, Dilantin, statins, Allegra, blood thinners, anti-anxiety drugs and some cancer medications should consult a pharmacist or health care provider before using milk thistle.

  According to a 1994 study reported in Volume 55 of the Current Therapeutic Research Journal, use of milk thistle concomitant with butyrophenones or phenothiazines may reduce lipid peroxidation.

  According to a study published in the Journal of Pharmacy and Pharmacology, milk thistle has an antagonistic effect if it is given at the same time as yohimbine or phentolamine.