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Buckthorn (Rhamnus spp., Frangula spp.)

While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.

Related Terms

  • 3′-O-acetylfrangulin, aglycones, Alaternus buckthorn, alder buckthorn, alder-leaf buckthorn, alderleaf buckthorn, alizarin, anthranoids, anthraquinone, Asian Chinese buckthorn, Avignon buckthorn, birchleaf buckthorn, California buckthorn, Carolina buckthorn, cascara, Cascara buckthorn, cascara sagrada, chitticum, coffeeberry, common buckthorn, coyotillo, Dahurian buckthorn, dichloromethanes, dimeric anthracenone, dogwood, Dyer’s buckthorn, emodin, flavonols, Frangula alnus, Frangula azorica, Frangula betulifolia, Frangula californica, Frangula caroliniana, Frangula purshiana, Frangula rubra, Frangula sphaerosperma, gesho, hartsthorn, highwaythorn, hollyleaf buckthorn, hollyleaf redberry, Hoxsey formula, Island redberry buckthorn, Italian buckthorn, Japanese buckthorn, Karwinskia humboldtiana, lanceleaf buckthorn, Lokao buckthorn, methanol, Persian berry, prinoidin bianthrones, prinoidin-emodin bianthrones, purging buckthorn, Pursh’s buckthorn, R. alaternus, R. alnifolia, R. cathartica, R. crocea, R. (F.) californica, R. (F.) caroliniana, R. (F.) purshiana, R. glandulosa, R. infectoria, R. prinoides, R. utilis, ramsthorn, red buckthorn, redberry buckthorn, Rhamnaceae (family), rhamnepalins, rhamnosylanthraquinone, rhamnosylanthrones, Rhamnus alaternus, Rhamnus alnifolia, Rhamnus arguta, Rhamnus betulaefolia, Rhamnus californica, Rhamnus caroliniana, Rhamnus cathartica, Rhamnus cathartica L., Rhamnus crocea, Rhamnus davurica, Rhamnus diffuses, Rhamnus frangula, Rhamnus glandulosa, Rhamnus globosa, Rhamnus ilicifolia, Rhamnus infectoria, Rhamnus japonica, Rhamnus lanceolata, Rhamnus latifolia, Rhamnus libanotica, Rhamnus lycioides, Rhamnus nepalensis, Rhamnus petiolaris, Rhamnus pirifolia, Rhamnus prinoides, Rhamnus purshiana, Rhamnus rubra, Rhamnus saxatilis, Rhamnus serrata, Rhamnus smithii, Rhamnus sphaerosperma, Rhamnus staddo, Rhamnus tinctoria, Rhamnus utilis, rock buckthorn, Sanguinho, sawleaf buckthorn, sharp-tooth buckthorn, shiny-leaf buckthorn, Smith’s buckthorn, Staddo, toxin T-514, tullidora, waythorn, West Indian buckthorn.


  • Species of buckthorn, which are shrubs or trees that usually grow to a height of 1-10 meters, are widely spread in temperate and subtropical parts of the world. They are classified as belonging to the family Rhamnaceae but may be subclassified into either Rhamnus or Frangula genera.
  • Traditionally, the berries and bark of buckthorn species have been used for stomach disorders. Buckthorn, especially its bark, is known to increase bowel movements in animals and people. The bark of the largest buckthorn, Rhamnus purshiana, is often called cascara sagrada or chitticum bark. The berries, harvested when fully ripe, may increase urine production or cause violent laxative properties.
  • The laxative effect of buckthorn may be caused by chemicals that also damage cells that line the colon and may promote tumor formation. Therefore, it is suggested that such laxatives, including buckthorn, be used only for short time periods.
  • Current research is investigating of the ability of buckthorn to prevent mutations and cause toxic effects against cancer cells. More recently, limited studies have investigated the ability of buckthorn to prevent cell growth, prevent mutations, and cause antioxidant effects.
  • Buckthorn is not generally recognized as safe and effective by the U.S. Food and Drug Administration (FDA).

Scientific Evidence


These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

C Intestinal blockage

Preliminary evidence suggests that buckthorn may be effective in treating intestinal blockage. Further research is required with buckthorn alone before a firm conclusion may be made.

*Key to grades:


The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

  • Antifungal, antimutagenic (prevents mutation), antineoplastic (anticancer), antioxidant, diabetes, fevers, hemorrhage, kidney problems, ocular disorders (sore eyes), respiratory ailments (breathing problems), tonic.


The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

  • There is no proven safe or effective dose for buckthorn in adults.

Children (under 18 years old)

  • There is no proven safe or effective dose for buckthorn in children.


The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.


  • Avoid using buckthorn in individuals with a known allergy or sensitivity to buckthorn, its parts, or members of the Rhamnaceae family.
  • Rhamnus purshiana (cascara sagrada) may be a potential cause of occupational asthma and rhinitis (nasal congestion).

Side Effects and Warnings

  • Buckthorn may cause abdominal cramps, asthma, colon dysfunction, colorectal cancer, epithelial cell death (death of body surface cells), hypocalcemia (low calcium levels), melanosis coli (abnormal colon color), nausea, rhinitis (nasal congestion), tumor growth, and vomiting.
  • Buckthorn may cause low blood pressure. Caution is advised in people taking drugs, herbs, or supplements that lower blood pressure.
  • Use cautiously in all people, as buckthorn may act as a stimulant laxative and cause nausea, vomiting, and abdominal cramps.
  • Avoid using buckthorn long-term, since using for more than 12 months may damage colon function, lead to melanosis coli (abnormal colon color), or promote cancer formation.
  • Avoid consuming green or ripe buckthorn fruit, as this may cause paralysis of the lower limbs. In severe cases, bulbar palsy (paralysis of certain muscles), or death may occur.
  • Avoid using buckthorn in people with abdominal pain, nausea, vomiting, or rectal bleeding.
  • Avoid using buckthorn in people with a known allergy or sensitivity to buckthorn, its components, or members of the Rhamnaceae family.
  • Avoid use in pregnant or breastfeeding women, or in children, due to a lack of safety information.

Pregnancy and Breastfeeding

  • There is currently a lack of scientific evidence on the use of buckthorn during pregnancy or breastfeeding.


Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

  • Buckthorn may cause low blood pressure. Caution is advised in people taking drugs that lower blood pressure.
  • Buckthorn may interact with anticancer agents, calcium, drugs that are eliminated from the body by the kidney, and laxatives.

Interactions with Herbs and Dietary Supplements

  • Buckthorn may cause low blood pressure. Caution is advised in people taking herbs or supplements that lower blood pressure.
  • Buckthorn may interact with calcium, fiber, herbs or supplements that are eliminated from the body by the kidneys, and laxatives.

Author Information

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (


Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to Selected references are listed below.

  1. Ammar RB, Bouhlel I, Valenti K, et al. Transcriptional response of genes involved in cell defense system in human cells stressed by H2O2 and pre-treated with (Tunisian) Rhamnus alaternus extracts: combination with polyphenolic compounds and classic in vitro assays. Chem Biol Interact. 7-20-2007;168(3):171-183. View Abstract
  2. Chakurski I, Matev M, Koichev A, Angelova I, Stefanov G. [Treatment of chronic colitis with an herbal combination of Taraxacum officinale, Hipericum perforatum, Melissa officinaliss, Calendula officinalis and Foeniculum vulgare]. Vutr.Boles. 1981;20(6):51-54. View Abstract
  3. Giavina-Bianchi PF, Castro Jr. FF, Machado ML, Duarte AJ. Occupational respiratory allergic disease induced by Passiflora alata and Rhamnus purshiana. Ann.Allergy Asthma Immunol 1997;79(5):449-454. View Abstract
  4. Gomez-Silva M, Garza-Ocanas L, Waksman N, Rivas V, Pineyro-Lopez A. In vitro metabolism and toxicity assessment of toxin T-514 (Peroxisomicine A1) of Karwinskia humboldtiana in microsomes and primary cultured hepatocytes. Toxicol In Vitro 2005;19(1):47-53. View Abstract
  5. Huang HC, Lee CR, Chao PD, Chen CC, Chu SH. Vasorelaxant effect of emodin, an anthraquinone from a Chinese herb. Eur J Pharmacol 12-3-1991;205(3):289-294. View Abstract
  6. Hypocalcemia due to cascara intoxication. Am Pract Dig.Treat. 1954;5(5):396-398. View Abstract
  7. Manojlovic NT, Solujic S, Sukdolak S, Milosev M. Antifungal activity of Rubia tinctorum, Rhamnus frangula and Caloplaca cerina. Fitoterapia 2005;76(2):244-246. View Abstract
  8. Matev M, Chakurski I, Stefanov G, Koichev A, Angelov I. [Use of an herbal combination with laxative action on duodenal peptic ulcer and gastroduodenitis patients with a concomitant obstipation syndrome]. Vutr.Boles. 1981;20(6):48-51. View Abstract
  9. National Toxicology Program. Toxicology and carcinogenesis studies of EMODIN (CAS NO. 518-82-1) feed studies in F344/N rats and B6C3F1 mice. Natl Toxicol Program Tech Rep Ser. 2001;493:1-278. View Abstract
  10. Pineyro-Lopez A, Martinez de Villarreal L, Gonzalez-Alanis R. In vitro selective toxicity of toxin T-514 from Karwinskia humboldtiana (buckthorn) plant on various human tumor cell lines. Toxicology 9-6-1994;92(1-3):217-227. View Abstract
  11. Siegers CP, von Hertzberg-Lottin E, Otte M, Schneider B. Anthranoid laxative abuse–a risk for colorectal cancer? Gut 1993;34(8):1099-1101. View Abstract
  12. Standish LJ, Greene K, Greenlee H, Kim JG, Grosshans C. Complementary and alternative medical treatment of breast cancer: a survey of licensed North American naturopathic physicians. Altern Ther Health Med 2002;8(5):68-70. View Abstract
  13. Turner NJ, Hebda RJ. Contemporary use of bark for medicine by two Salishan native elders of southeast Vancouver Island, Canada. J Ethnopharmacol 1990;29(1):59-72. View Abstract
  14. van Gorkom BA, de Vries EG, Karrenbeld A, Kleibeuker JH. Review article: anthranoid laxatives and their potential carcinogenic effects. Aliment.Pharmacol Ther 1999;13(4):443-452. View Abstract
  15. Willems M, van Buuren HR, de Krijger R. Anthranoid self-medication causing rapid development of melanosis coli. Neth.J Med 2003;61(1):22-24. View Abstract

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.