A genus of 125 species of deciduous and evergreen, often thorny trees and shrubs that occur mainly in northern temperate regions. Rhamnus frangula and R. cathartica are ideal for hedges in a wild or woodland garden. The former, which grows wild in damp, peaty ground, has good autumn color, and its flowers are especially attractive to bees. It was once grown to make charcoal for small-arms gunpowder. Rhamnus purshiana, which is native to coastal redwood and mixed evergreen forests, is particularly noticeable in winter, forming groups of upright, silver-gray stems. The bark of Rhamnus species contains anthraquinone glycosides, which have strong purgative effect and cause severe griping pains, nausea, and vomiting unless stored for at least a year after drying. Rhamnus cathartica has been used as a purgative since at least the 9th century and was included in the British Phamacopoeia in 1650. Its effect is so drastic that it is no longer prescirbed, although buckthorn syrup, made from the berries, is used in veterinary practice. Rhamnus frangula and R. purshiana have superseded R. cathartica in medicine, having a gentler effect; the latter is mild enough for treating children and the elderly. Rhamnus purshiana was first listed in the U.S. Pharmacopoeia in 1890. Indiscriminate stripping of bark, leading to the destruction or some 100,000 trees a year, was reported as early as 1909, and shortages led to the exploitation of the much smaller R. alnifolia (alder buckthorn), which is similar in chemistry. Anthraquinones are pigments, so plants that contain them are almost always used for dyeing — a purpose that usually predates their importance in medicine. Rhamnus infectoria (Avignon berry) was one an important source of yellow dye; R. davurica and R. utilis were sources of the pigment known as "Chinese green indigo", used in dyeing silk. Fruits of R. cathartica, known as "Rhine berries", also yield an artist's pigment.

This laxative herb is so strong that it's usually used only as a last resort. Chemicals in buckthorn called anthraquinones stimulate the muscles of the intestinal tract, greatly increasing the urge to defecate and sometimes causing diarrhea and abdominal pain.

Dense, thicket-forming deciduous shrub or small tree with gray-brown bark, and ovate to elliptic leaves, to 6cm (2½in) long, which turn yellow in autumn. Tiny yellow-green, 4-petaled flowers are borne in axillary clusters in late spring, followed by globose red berries, about 6mm (¼in) across.

Common Name:
Other Names:
Hartsthorn, Highwaythorn, Ramsthorn, Waythorn
Botanical Name:
Rhamnus catharticus
Native Location:
Europe, NW Africa, and Asia
Well-drained soil in sun or partial shade. Rhamnus cathartica prefers alkaline soil, R. frangula neutral to acid soil. Shorten of thin out branches, and remove dead wood, in late winter or early spring.
By seed sown when ripe; by greenwood cuttings in early summer; by layering in autumn or early spring.
Bark is stripped from young plants during spring and early summer, and it is dried for one to two years before being used in decoctions, liquid extracts, powders, and tablets. Bark from two-year-old plants is preferred in the case of R. frangula. Fruits (R. cathartica) are collected when ripe and they are made into syrup.
6m (20ft)
5m (15ft)
Parts Used:
Bark, fruits
A bitter, cooling, purgative herb that cleanses toxins from tissues and has diuretic effects.
Medicinal Uses:
Internally for constipation. Small amounts are occasionally used in alterative formulas to treat skin diseases, intestinal parasites, and gallstones.
To treat constipation and poor digestion; as a diuretic in "blood-purifying" remedies. Germany's Commission E has approved the use of Buckthorn to treat constipation.
Typical Dose:
A typical dose of buckthorn may range from 2 to 5 gm per day.
Possible Side Effects:
Buckthorn's side effects include, nausea, vomiting, loss of appetite, abdominal cramps, and nervousness. Long-term use leads to dehydration and loss of electrolytes, especially potassium.
Drug Interactions:
Digoxin, Diuretics, Loop Diuretics, Oral Corticosteroids, Thiazide Diuretics
Taking buckthorn with these drugs may reduce or prevent drug absorption:
All drugs taken orally, (Due to the herb's laxative effect)
Taking Buckthorn with these drugs may interfere with the action of the drug:
Acebutolol, (Novo-Acebutolol, Sectral) Adenosine, (Adenocard, Adenoscan) Amiodarine, (Cordarone, Pacerone) Bretylium, (Bretylium)
Digoxin, (Digitek, Lanoxin) Diltiazem, (Cardizem, Tiazac) Disopyramide, (Norpace, Rhythmodan) Dofetilide, (Tikosyn)
Esmolol, (Brevibloc) Flecainide, (Tambocor) Ibutilide, (Corvert) Lidocaine, (Lidoderm, Xylocaine)
Mexiletine, (Mexitil, Novo-Mexiletine) Moricizine, (Ethmozine) Phenytoin, (Dilantin, Phenytek) Procainamide, (Procanbid, Pronestyl-SR)
Propafenone, (Gen-Propafenone, Rhythmol) Propranolol, (Inderal, InnoPran XL) Quinidine, (Novo-Quinidin, Quinagulate Dura-Tabs) Sotalol, (Betapace, Sorine)
Tocainide, (Tonocard)
Verapamil, (Calan, Isoptin SR)
Taking buckthorn with these drugs may increase the risk of hypokalemia (low levels of potassium in the blood):
Acetazolamide, (Apo-Acetazolamide, Diamox Sequels) Azosemide, (Diat) Beclomethasone, (Beconase, Vanceril) Betamethasone, (Celestone, Diprolene) Budesonide, (Entocort, Rhinocort)
Budesonide and Formoterol, (Symbicort) Bumetanide, (Bumex, Burinex) Chlorothiazide, (Diuril) Chlorthalidone, (Apo-Chlorthalidone, Thalitone) Cortisone, (Cortone)
Deflazacort, (Calcort, Dezacor) Dexamethasone, (Decadron, Dexasone) Ethacrynic Acid, (Edecrin) Etozolin, (Elkapin) Flunisolide, (Aerobid, Nasarel)
Fluorometholone, (Eflone, Flarex) Fluticasone, (Cutivate, Flonase) Furosemide, (Apo-Furosemide, Lasix) Hydrochlorothiazide, (Apo-Hydro, Microzide) Hydrocortisone, (Anusol-HC, Locoid)
Hydroflumethiazide, (Diucardin, Saluron) Indapamide, (Lozol, Nu-Indapamide) Loteprednol, (Alrex, Lotemax) Mannitol, (Osmitrol, Resectisol) Medrysone, (HMS Liquifilm)
Mefruside, (Baycaron)—Used for elevated blood pressure Methazolamide, (Apo-Methazolamide, Neptazane) Methyclothiazide, (Aquatensen, Enduron) Methylprenisolone, (Depo-Medrol, Medrol) Metolazone, (Mykrox, Zaroxolyn)
Olmesartan and Hydrochlorothiazide, (Benicar HCT) Polythiazide, (Renese) Prednisolone, (Inflamase Forte, Pred Forte) Prednisone, (Apo-Prednisone, Deltasone) Rimexolone, (Vexol)
Torsemide, (Demadex) Triamcinolone, (Aristocort, Trinasal) Trichlormethiazide, (Metatensen, Naqua) Urea, (Amino-Cerv, UltraMide) Xipamide, (Diurexan, Lumitens)
Taking buckthorn with these drugs may interfere with the actions of the herb:
Aluminum Hydroxide, (AlternaGel, AluCap) Aluminum Hydroxide and Magnesium Carbonate, (Gaviscon Extra Strength, Gaviscon Liquid) Aluminum Hydroxide and Magnesium Hydroxide, (Maalox, Rulox) Aluminum Hydroxide and Magnesium Trisilicate, (Gaviscon Tablet)
Aluminum Hydroxide, Magnesium Hydroxide, and Simethicone, (Maalox, Mylanta Liquid) Calcium Carbonate, (Rolaids Extra Strength, Tums) Calcium Carbonate and Magnesium Hydroxide, (Mylanta Gelcaps, Rolaids Extra Strength) Famotidine, Calcium Carbonate, and Magnesium Hydroxide, (Pepsid Complete)
Magaldrate and Simethicone, (Riopan Plus, Riopan Plus Double Strength) Magnesium Hydroxide, (Dulcolax Milk of Magnesia, Phillips' Milk of Magnesia) Magnesium Oxide, (Mag-Ox 400, Uro-Mag) Magnesium Sulfate, (Epsom Salts)
Sodium Bicarbonate, (Brioschi, Neut)
Lab Test Alteration:
May confound results of diagnostic urine tests that rely on a color change by turning urine different colors.
Disease Effects:
May worsen cases of Crohn's disease, irritable bowel syndrome, ulcerative colitis, or other gastrointestinal diseases.
Food Interactions:
The action of buckthorn may be inhibited by milk.
Supplement Interactions:
All parts, especially the berries are harmful if eaten. Sap and berries are skin irritants.
Economic Uses:
Bark and fruits yield a yellow dye, once used to color paper and maps. Fruits are mixed with gum arabic and limewater to make a green pigment used in watercolor painting.
Encylopedia of Herbs by Deni Brown Copyright ©: 1995, 2001 Dorling Kindersley Limited pp 342-343
The Essential Herb-Drug-Vitamin Interaction Guide By Geo. T.Grossberg,MD and Barry Fox,PhD Copyright©2007 Barry Fox,PhD. Pp. 100-102