Dandelion and milk thistle plants are members of the same plant family, Compositae. They originated in Europe and now grow wild across North America, according to Medicinal Herb Info. In spite of their reputation as unwanted weeds, they're both valuable medicinal herbs. Before beginning to take any medicinal herbs or supplements, consult your health care provider for instructions.
Milk Thistle & Dandelion
Dandelion and milk thistle are traditionally used to treat various liver conditions, but each has a number of other medicinal uses. The website for the Memorial Sloan-Kettering Cancer Center, or MSKCC, says dandelion is commonly used as a liver treatment and to treat cancer, diabetes, eczema, gastrointestinal disorders and rheumatoid arthritis. The site also reports that milk thistle is used for cancer prevention, alcoholism, cirrhosis of the liver, food poisoning, hepatitis and indigestion. However, the National Center for Complementary & Alternative Medicine, or NCCAM, website says both herbs can upset the stomach when taken. This may be avoided if the supplements are taken with food.
The NCCAM has funded a number of clinical studies on the use of milk thistle to treat various conditions, and the results seem promising. It suggests that more research be done before the herb can be recommended. And even though dandelion has a time-honored tradition of medicinal use, the NCCAM site claims there is no clinical proof that it works in treating medical conditions.
Possible Side Effects
The MSKCC website reports that dandelion and milk thistle could cause an upset stomach or mild diarrhea when taken. Potentially, these could be avoided by taking the supplements with meals. Other possible side effects are described on the U.S. National Library of Medicine, or USNLM, website as lowering blood sugar levels and potential excess bleeding.
Dandelion may have harmful interactions with some other herbs and medications, says the USNLM site. The site warns people who take antibiotics, medications for diabetes, diuretics, lithium, medications for the heart such as digoxin, corticosteroids, nicotine, blood thinners, cholesterol-lowering drugs, anti-inflammatories, certain antacids, anticancer agents, appetite suppressants, laxatives and gout medications to avoid taking dandelion. The University of Maryland Medical Center, or UMMC, website cautions people taking allergy drugs, medications for high cholesterol, anti-anxiety medications, blood thinners, some cancer drugs, antipsychotics and seizure medications to avoid taking milk thistle, due to possible interactions. If you have questions about whether dandelion or milk thistle will interact harmfully with medications or supplements you take, discuss it with a pharmacist or health care provider.
Dandelion can be found as fresh leaves, dried leaves, dried root, leaf tincture, root tincture and standardized powdered extract forms, according to the UMMC website. The site also says that milk thistle is available in capsules, standardized dried herb, liquid extract and tincture. Both can also be made into teas.
According to the NCCAM website, people with known allergies to other members of the plant family Compositae such as chamomile, chrysanthemums, yarrow, feverfew, ragweed, marigold or daisy should not use dandelion or milk thistle. They could also cause an allergic reaction. Allergic reactions can occur even if a substance has been used before with no reaction. Watch for signs of swelling of the lips, tongue, throat, face or a rash. If any of these occur, stop using the herbs and contact your health care provider.