Activella, Agnus Castus, Alfalfa, Alora, Amber Touch-and-Heal, American Ginseng, Anchi, Angeliq, Asclepias tuberosa, Barbasco, Black Cohosh, Butterfly Weed, Cabbage Palm, Canada Root, Canadian Ginseng, Cenestin, Chaste Tree, Chasteberry, Cimicifuga racemosa, Climara, ClimaraPro, Cloister Pepper, Colic Root, CombiPatch, Conjugated Estrogen, Conjugated Estrogen Vaginal Cream, Conjugated Estrogens and Medroxyprogesterone, Conjugated Estrogens Injection, Cow Clover, Dehydroepiandrosterone, DHEA, Dioscorea species, Drospirenone and Ethinyl Estradiol, Drospirenone and estradiol tablets, Esclim, Esterfied Estrogens and Methyltestosterone, Esterified Estrogens, Estrace, Estrace Vaginal Cream, Estraderm Patch, Estradiol, Estradiol and Levonorgestrel, Estradiol and Norethindrone Acetate Oral, Estradiol and Norethindrone Transdermal Patch, Estradiol and Norgestimate, Estradiol Topical Emulsion, Estradiol Topical Gel, Estradiol Transdermal System, Estradiol Vaginal Cream, Estradiol Vaginal Ring, Estradiol Vaginal Tablets, Estrasorb, Estratab, Estratest, Estratest H.S., Estring, EstroGel, Estrone Injection, Estropipate tablets, Etonogestrel and ethinyl estradiol vaginal ring, Fan Palm, FemPatch, Femring, Feuille de Luzerna, Five Fingers, Flux Root, Ginseng, American, GL701, Glycine max, Glycine soja, Gynodiol, Hardhay, Hypericum, Hypericum perforatum, Klamath Weed, Lucerne, Lunelle, Meadow Clover, Medicago, Medicago sativa, Medroxyprogesterone acetate and Estradiol cypionate injection, Menest, Menostar, Millepertuis, Monk's Berry, Monk's Pepper, North American Ginseng, NuvaRing, Ogen, Orange Milkweed, Orange Swallow-wort, Ortho-Est, Ortho-Prefest, Panax quinquefolius, Pleurisy root, Prasterone, Prefest, Premarin, Premarin Intravenous, Premarin Vaginal Cream, Premphase, Prempro, Purple Clover, Purple Medick, Red Berry, Red Clover, Ren Shen, Rosin Rose, Sabal, Sabal serrulata, Saw Palmetto, Scrub Palm, Serenoa, Serenoa repens, Silkweed, SJW, Soy, Soya, Soybeans, St. John's Wort, Swallow-wort, Syntest D.S., Syntest H.S., Tipton Weed, Trefoil, Trifolium pratense, Tuber Root, Vagifem, Vitex, Vitex agnus-castus, Vivelle, Vivelle-Dot, White Root, Wild Clover, Wild Root, Wild Yam, Yasmin, Yuma.
Quick guide to Lady's Thistle
Scientific Name: Milk Thistle
Other Names: Cardui mariae, Carduus marianum, Holy Thistle, Lady's Thistle, Legalon, Marian Thistle, Mariendistel, Mary Thistle, Our Lady's Thistle, Silimarina, Silybin, Silybum marianum, Silymarin, St. Mary Thistle
Who is this for?
Milk thistle contains several chemicals with possible medical effects. Most current research focuses on one of them, silymarin, which may have specific protective effects on cells in the liver. In multiple human, animal, and laboratory studies, it has shown differing degrees of effectiveness for protecting the liver from damage caused by alcohol, chemicals, drugs, diseases, and poisonous plants. Silymarin and other chemicals in milk thistle are believed to protect liver cells in several different ways:
Silymarin has antioxidant properties. Antioxidants are thought to prevent or lessen damage to body cells that is caused by a chemical process called oxidation.Silymarin and other chemicals from milk thistle have also been tested in laboratory studies involving various types of human cancer cells. In general, they seem to interrupt cancer cell division as well as shortening the time that cancer cells live. They may also stop or limit the formation of new blood vessels that supply tumors. Most research has centered on breast cancer and prostate cancer, but milk thistle may also be useful in treating other cancers such as leukemia. The application of another milk thistle chemical, silibinin, to the skin of laboratory animals has protected the animals against the development of skin cancer either before or immediately after exposure to damaging radiation. In addition, some chemicals from milk thistle may increase the effectiveness of current anticancer drugs. Some of these anticancer effects are being studied in early-phase human trials, but none is confirmed, yet.
Milk thistle and chemicals derived from it are being studied for a number of additional potential effects. For example, in animal studies and one small study in humans, milk thistle produced modest reductions in cholesterol levels. Results of separate laboratory studies show that milk thistle may help to protect the heart muscle from damage caused by certain drugs. However, these potential uses have not been well-studied in humans nor have they been proved in animal or laboratories studies.
When should I be careful taking it?
Women with hormone-dependent conditions such as endometriosis, uterine fibroids, and cancers of the breast, ovaries, or uterus should not take or use milk thistle plant extract due to its possible estrogenic effects.
Pregnant women should not take milk thistle because of its possible estrogen-like effects, which could interfere with normal fetal development.
Men who have prostate cancer should not take milk thistle without the approval of a doctor.
Some cases of skin rash from touching milk thistle plants have been reported in the medical literature. Milk thistle belongs to the same family of plants as chrysanthemums, daisies, and ragweed. Individuals who are sensitive to those plants may also be sensitive to milk thistle.
What side effects should I watch for?
No severe side effects have been reported from taking milk thistle. Doses greater than 2500 mg (2.5 grams) per day have been reported to have a slight laxative effect, however.
Occasionally, individuals taking milk thistle have reported:
What interactions should I watch for?
Milk thistle may interfere with the effectiveness of estrogen by blocking an enzyme that breaks down estrogen in the body. As a result, estrogen products may not be as effective in reducing the symptoms of menopause or preventing osteoporosis. In addition, oral contraceptives may not be as effective and an unintended pregnancy could result.
Because it is broken down by certain enzymes in the liver, milk thistle may possibly interfere with the effectiveness of prescription drugs that are processed by the same enzymes. Some of these drugs are:
No interactions have been reported between milk thistle and non-prescription drugs, other herbal supplements, or foods. However, because few reliable studies of milk thistle have been conducted, its possible interactions with drugs, foods, and other dietary supplements are not completely understood. Be sure that your doctor or pharmacist is aware of all the prescription and non-prescription medicines you take before you begin to use milk thistle or any other herbal supplement.
Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals.
Should I take it?
Milk thistle gets its name from the thick white fluid that seeps from the leaves when they are broken. Its long leaves have prominent white veins and sharp spines that can scratch unprotected skin. Purple or pink flowers that grow individually on tall stems bloom in mid-to-late summer. Each milk thistle plant has up to 50 flowers; each flower contains about a hundred seeds. The seeds resemble dandelion seeds, since they are attached to feathery structures that blow in the wind. Thought to have originated in areas around the Mediterranean Sea and possibly regions of India, milk thistle is now found growing wild in most parts of the world with moderate temperatures including Canada, Europe, and the United States. It grows as an annual in cooler climates or a biennial in bush that can be as tall as ten feet and that has a very strong taproot. Because it spreads rapidly, grows in marginal areas such as vacant lots, and crowds out other plants; milk thistle is often considered to be a weed. It may poison cattle and other livestock that eat large amounts of whole plants.
Currently, milk thistle seeds are the part most commonly used in medicine. All the parts that grow above the ground may be used, however, to make extracts. In the past, milk thistle products have been used to stimulate the flow of breast milk in women who were breast-feeding infants. It was also a folk remedy for depression. Its leaves, roots, and stems have been eaten as a vegetable in some parts of the world, and its seeds may be toasted and boiled into a coffee-type beverage.
Dosage and Administration
Most of the milk thistle products used in human studies were standardized to contain between 70% and 80% of silymarin. Standardization by the manufacturer should assure the same amount of active ingredient in every batch of the commercial preparation. Standardization of herbal products is not required by the U.S. Food and Drug Administration (FDA), so not every product sold in the United States will contain the same amounts of active ingredients.
Standardized commercial preparations of milk thistle are common in Europe. An injectable form of silymarin is also used by European physicians, but it is not available in the United States. In North America, milk thistle is sold most often as an extract, which is a concentrated liquid preparation made by soaking one or more of the chopped or mashed aerial parts of milk thistle plants (flowers, leaves, seeds, and stems) in a liquid such as alcohol. This semi-liquid preparation is then strained to filter out the solid parts. It can be packaged as a liquid or dried and made into capsules or tablets. Extracts made only from the seeds of milk thistle are thought not to have estrogen-like effects. The active chemicals in milk thistle do not dissolve very well in water, so making a tea from dried milk thistle is not very useful.
A typical daily dose of milk thistle extract is 200 mg to 420 mg in one, two, or three doses. In clinical studies, the most common length of dosing was 4 weeks to 8 weeks.
Milk thistle is effective at protecting the liver from toxic substances. In many parts of the world, it is used as an emergency measure to prevent death from eating poisonous mushrooms and it is taken to prevent or lessen liver damage from some medications and industrial chemicals. It may also have some usefulness for liver diseases such as hepatitis and cirrhosis including alcohol-induced liver damage.Also used to promote milk production for women who are breast-feeding, milk thistle has mild estrogenic effects that may make it useful for treating prostate cancer. It is thought to reduce cholesterol to some degree, but more studies are needed to prove its usefulness in the treatment of high cholesterol.
Due to the estrogen-like effect that may be associated with taking milk thistle plant extract, pregnant women and women with hormone-dependent conditions should not take it. Men who have prostate cancer should not take it without the approval of a doctor.
Touching milk thistle plants may cause a skin rash.
Side effects from using milk thistle are reported to be mild. They include general gastrointestinal upset.
Milk thistle may interfere with the effects of estrogen replacement therapy and oral contraceptives due to its possible estrogenic effects. The effectiveness of drugs that are broken down by the same enzymes that break down milk thistle may also be affected. If you take prescription medications, ask your doctor or pharmacist about possible interactions before you begin to take milk thistle.
Agency for Health Care Policy and Research. Milk thistle: effects on liver disease and cirrhosis and clinical adverse effects. Summary. Evidence Report/Technology Assessment Number 21. September 2000. Available at: http://ahcpr.gov/clinic/epscums/milktsum.htm Accessed February 12, 2003.
Anon: Milk thistle. In: DerMarderosian A, Beutler JA, eds. Facts and Comparisons: The Review of Natural Products. St. Louis, MO, Facts and Comparisons. January 1997.
Arizona Board of Regents. An Illustrated Guide to Arizona Weeds. Tucson, Arizona. The University of Arizona Press. 1972. Available at: http://wwwuapress.arizona.edu/online.bks/weds/milkthis.htm Accessed March 6, 2003.
Awang D. Milk thistle. Canadian Pharmaceutical Journal. 1993;126:402-404 and 422.
Bean C. The Nature Conservancy. Element Stewardship Abstract for Silybum marianum. Available at: http://tncweeds.ucdavis.edu/esadocs/documnts/silymar.html Accessed March 6, 2003.
Bean P. The use of alternative medicine in the treatment of hepatitis C. American Clinical Laboratory. 2002;21(4):19-21.
Buzzelli G, Moscarella S, Giusti A, Duchini A, Marena C, Lampertico M. A pilot study of the liver protective effect of silybin-phosphatidylcholine complex (idb1016) in chronic active hepatitis. International Journal of Clinical Pharmacology, Therapy, and Toxicology. 1993. 31(9):456-460.
Chlopcikova S, Psotova J, Miketova P, Simanek V. Chemoprotective effect of plant phenolics against anthracycline-induced toxicity on rat cardiomyocytes. Part I. Silymarin and its flavonolignans. Phytotherapy Research. 2004;18(2):107-110.
Chu SC, Chiou HL, Chen PN, Yang SF, Hsieh YS. Silibinin inhibits the invasion of human lung cancer cells via decreased productions of urokinase-plasminogen activator and matrix metalloproteinase-2. Molecular Carcinogens. 2004;40(3):143-149.
Crocenzi FA, Sanchez Pozzi EJ, Pellegrino JM, et al. Beneficial effects of silymarin on estrogen-induced cholestasis in the rat: a study in vivo and in isolated hepatocyte couplets. Hepatology. 2001;34(2):329-339.
Dehmlow C, Erhard J, de Groot H. Inhibition of Kupffer cell functions as an explanation for the hepatoprotective properties of silibinin. Hepatology. 1996;23(4):749-754.
Dhanalakshmi S, Agarwal P, Glode LM, Agarwal R. Silibinin sensitizes human prostate carcinoma DU145 cells to cisplatin- and carboplatin-induced growth inhibition and apoptotic death. International Journal of Cancer. 2003;106(5):699-705.
Dhanalakshmi S, Mallikarjuna GU, Singh RP, Agarwal R. Silibinin prevents ultraviolet radiation-caused skin damages in SKH-1 hairless mice via a decrease in thymine dimer positive cells and an up-regulation of p53-p21/Cip1 in epidermis. Carcinogenesis. 2004;25(8):1459-1465.
DiCenzo R, Shelton M, Jordan K, Koval C, Forrest A, Reichman R, Morse G. Coadministration of milk thistle and indinavir in healthy subjects. Pharmacotherapy. 2003;23(7):866-870.
Ferenci P, Dragosics B, Dittrich H, Frank H, Benda L, Lochs H, et al. Randomized controlled trial of silymarin treatment in patients with cirrhosis of the liver. Journal of Hepatology. 1989;9(1):105-113.
Flora K, Hahn M, Rosen H, Benner K. Milk thistle (Silybum marianum) for the therapy of liver disease. American Journal of Gastroenterology. 1998;93(2):139-143.
Fraschini F, Demartini G, Esposti D. Pharmacology of silymarin. Clinical Drug Investigation. 2002;22(1):51-65.
Giese LA. Milk thistle and the treatment of hepatitis. Gastroenterology Nursing. 2001;24(2):95-97.
Hernandez R, Nazar E. Effect of silymarin in intrahepatic cholestasis of pregnancy (preliminary communication)[Article in Spanish] Rev Chil Obstet Ginecol. 1982;47(1):22-29.
Ioannides C. Pharmacokinetic interactions between herbal remedies and medicinal drugs. Xenobiotica. 2002;32(6):451-478.
Jacobs BP, Dennehy C, Ramirez G, Sapp J, Lawrence VA. Milk thistle for the treatment of liver disease: a systematic review and meta-analysis. American Journal of Medicine. 2002;113(6):506-515.
Jellin JM, Gregory P, Batz F, Hitchens K, et al, eds. Pharmacist's Letter/Prescriber's Letter. Natural Medicines Comprehensive Database, 3rd Edition. Stockton CA: Therapeutic Research Facility, 2000.
Johnson VJ, He Q, Osuchowski MF, Sharma RP. Physiological responses of a natural antioxidant flavonoid mixture, silymarin, in BALB/c mice: III. Silymarin inhibits T-lymphocyte function at low doses but stimulates inflammatory processes at high doses. Planta Medica. 2003;69(1):44-49.
Kohno H, Tanaka T, Kawabata K, Hirose Y, Sugie S, Tsuda H, Mori H. Silymarin, a naturally occurring polyphenolic antioxidant flavonoid, inhibits azoxymethane-induced colon carcinogenesis in male F344 rats. International Journal of Cancer. 2002;101(5):461-468.
Krecman V, Skottova N, Walterova D, Ulrichova J, Simanek V. Silymarin inhibits the development of diet-induced hypercholesterolemia in rats. Planta Medica. 1998;64(2):138-142.
Ladas EJ, Kelly KM. Milk thistle: is there a role for its use as an adjunct therapy in patients with cancer? Journal of Alternative and Complementary Medicine. 2003;9(3):411-416.
Lee DG, Kim HK, Park Y, Park SC, Woo ER, Jeong HG, Hahm KS. Gram-positive bacteria specific properties of silybin derived from Silybum marianum. Archives of Pharmaceutical Research. 2003;26(8):597-600.
Li LH, Wu LJ, Zhou B, et al. Silymarin prevents UV irradiation-induced A375-S2 cell apoptosis. Biology and Pharmacology Bulletin. 2004;27(7):1031-1036.
Lieber CS, Leo MA, Cao Q, Ren C, DeCarli LM. Silymarin retards the progression of alcohol-induced hepatic fibrosis in baboons. Journal of Clinical Gastroenterology. 2003;37(4):336-339.
Maghrani M, Zeggwagh NA, Lemhadri A, El Amraoui M, Michel JB, Eddouks M. Study of the hypoglycaemic [sic] activity of Fraxinus excelsior and Silybum marianum in an animal model of type 1 diabetes mellitus. Journal of Ethnopharmacology. 2004;91(2-3):309-316.
Muriel P, Mourelle M. The role of membrane composition in ATPase activities of cirrhotic rat liver: effect of silymarin. Journal of Applied Toxicology. 1990;10(4):281-284.
National Cancer Institute. Milk thistle (PDQ). Health professional version. Last modified June 23, 2004. Available at: www.nci.nih.gov/cancertopics/ pdq/cam/milkthistle/healthprofessional/allpages. Accessed October 14, 2004.
Pares A, Planas R, Torres M, Caballeria J, Viver JM, Acero D, et al. Effects of silymarin in alcoholic patients with cirrhosis of the liver: results of a controlled, double-blind, randomized and multicenter trial. Journal of Hepatology. 1998. 28(4):615-621.
Peirce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: Stonesong Press; 1999.
Piscitelli SC, Formentini E, Burstein AH, Alfaro R, Jagannatha S, Falloon J. Effect of milk thistle on the pharmacokinetics of indinavir in healthy volunteers. Pharmacotherapy. 2002;22(5):551-556.
Qi L, Singh RP, Lu Y, Agarwal R, Harrison GS, Franzusoff A, Glode LM. Epidermal growth factor receptor mediates silibinin-induced cytotoxicity in a rat glioma cell line. Cancer Biology and Therapeutics. 2003;2(5):526-531.
Saller R, Meier R, Brignoli R. The use of silymarin in the treatment of liver diseases. Drugs. 2001;61(14):2035-2063.
Scambia G, De Vincenzo R, Ranelletti FO, et al. Antiproliferative effect of silybin on gynaecological [sic] malignancies: synergism with cisplatin and doxorubicin. European Journal of Cancer. 1996;32A(5):877-882.
Seidlova-Wuttke D, Becker T, Christoffel V, Jarry H, Wuttke W. Silymarin is a selective estrogen receptor beta (ERbeta) agonist and has estrogenic effects in the metaphysis of the femur but no or antiestrogenic effects in the uterus of ovariectomized (ovx) rats. Journal of Steroid Biochemistry and Molecular Biology. 2003;86(2):179-188.
Singh RP, Agarwal R. Prostate cancer prevention by silibinin. Current Cancer Drug Targets. 2004;4(1):1-11.
Skottova N, Krecman V. Silymarin as a potential hypocholesterolaemic [sic] drug. Physiology Research. 1998;47(1):1-7.
Skottova N, Vecera R, Urbanek K, Vana P, Walterova D, Cvak L. Effects of polyphenolic fraction of silymarin on lipoprotein profile in rats fed cholesterol-rich diets. Pharmacology Research. 2003;47(1):17-26.
Somogyi A, Ecsedi GG, Blazovics A, Miskolczi K, Gergely P, Feher J. Short term treatment of type II hyperlipoproteinaemia [sic] with silymarin. Acta Medica Hungaria. 1989;46(4):289-295.
Sridar C, Goosen TC, Kent UM, Williams JA, Hollenberg PF. Silybin inactivates cytochromes P450 3A4 and 2C9 and inhibits major hepatic glucuronosyltransferases. Drug Metabolism and Disposition. 2004;32(6):587-594.
Svagera Z, Skottova N, Vana P, et al. Plasma lipoproteins in transport of silibinin, an antioxidant flavonolignan from Silybum marianum. Phytotherapy Research. 2003;17(5):524-530.
Thelen P, Jarry H, Ringert RH, Wuttke W. Silibinin down-regulates prostate epithelium-derived Ets transcription factor in LNCaP prostate cancer cells. Planta Medica. 2004;70(5):397-400.
Thelen P, Wuttke W, Jarry H, Grzmil M, Ringert RH. Inhibition of telomerase activity and secretion of prostate specific antigen by silibinin in prostate cancer cells. Journal of Urology. 2004;171(5):1934-1938.
Tyagi AK, Agarwal C, Chan DC, Agarwal R. Synergistic anti-cancer effects of silibinin with conventional cytotoxic agents doxorubicin, cisplatin and carboplatin against human breast carcinoma MCF-7 and MDA-MB468 cells. Oncology Reports. 2004;11(2):493-499.
Tyagi A, Agarwal C, Harrison G, Glode LM, Agarwal R. Silibinin causes cell cycle arrest and apoptosis in human bladder transitional cell carcinoma cells by regulating CDKI-CDK-cyclin cascade, and caspase 3 and PARP cleavages. Carcinogenesis. 2004;25(9):1711-1720.
Tyagi AK, Agarwal C, Singh RP, Shroyer KR, Glode LM, Agarwal R. Silibinin down-regulates survivin protein and mRNA expression and causes caspases activation and apoptosis in human bladder transitional-cell papilloma RT4 cells. Biochemistry and Biophysics Research Communications. 2003;312(4):1178-1184.
Tyagi A, Bhatia N, Condon MS, Bosland MC, Agarwal C, Agarwal R. Antiproliferative and apoptotic effects of silibinin in rat prostate cancer cells. Prostate. 2002;53(3):211-217.
Varga Z, Ujhelyi L, Kiss A, Balla J, Czompa A, Antus S. Effect of silybin on phorbol myristate actetate-induced protein kinase C translocation, NADPH oxidase activity and apoptosis in human neutrophils. Phytomedicine. 2004;11(2-3):206-212.
Wilasrusmee C, Kittur S, Shah G, Siddiqui J, Bruch D, Wilasrusmee S, Kittur DS. Immunostimulatory effect of Silybum Marianum (milk thistle) extract. Medical and Science Monitor. 2002;8(11):BR439-BR443.
Wu DF, Peng RX, Ye LP, Yu P. The effects of silymarin on hepatic microsomal and mitochondrial membrane fluidity in mice. [Article in Chinese] Zhongguo Zhong Yao Za Zhi. 2003 Sep;28(9):870-872.
Yoo HG, Jung SN, Hwang YS, et al. Involvement of NF-kappaB and caspases in silibinin-induced apoptosis of endothelial cells. International Journal of Molecular Medicine. 2004;13(1):81-86.
Zhao J, Agarwal R. Tissue distribution of silibinin, the major active constituent of silymarin, in mice and its association with enhancement of phase II enzymes: implications in cancer chemoprevention. Carcinogenesis. 1999;20(11):2101-2108.
Zhou S, Lim LY, Chowbay B. Herbal modulation of P-glycoprotein. Drug Metabolism Review. 2004;36(1):57-104.
(Note: The above information is not intended to replace the advice of your physician, pharmacist, or other healthcare professional. It is not meant to indicate that the use of the product is safe, appropriate, or effective for you.)