Eight species of Madagascar annuals and perennials are included in this genus. Catharanthus roseus has become a pantropical weed and is grown in temperate regions as an indoor plant or summer bedding plant for its attractive, periwinkle-like flowers. Extraction of alkaloids for medicinal uses was developed in the 1950s, after C. roseus was screened by an American pharmaceutical company for possible therapeutic properties. It contains more than 75 alkaloids, including vincristine and vinblastine, which have revolutionized cancer therapy, especially the treatment of acute leukemia in children. Isolated alkaloids are highly toxic and quite different in effect from the leaves, which have long been used in folk medicine for other purposes.

This popular garden flower with its star-shaped pink, purple, or white flowers has long been used as a folk remedy for diabetes, wasp stings, coughs, and colds. In recent years, scientists discovered that the Madagascar periwinkle contains as many as seventy alkaloids, some of which lower blood sugar levels, ease hypertension, stop bleeding, fight cancer, and have a powerful tranquilizing effect.

Small, erect perennial with smooth, shiny, oval leaves, up to 5cm (2in) long, and pink, flat-petaled flowers 4cm (1½in) across, with darker pink centers.

Common Name:
Other Names:
Cape Periwinkle, Catharanthus, Cayenne Jasmine, Church-Flower, Madagascar Periwinkle, Magdalena, Myrtle, Old Maid, Rosy Periwinkle
Botanical Name:
Catharanthus roseus syn. Vinca rosea
Native Locations:
Madagascar, now pantropical.
Moist well-drained soil in sun. Cut back in spring to maintain compact shape. Low temperatures and wet conditions may cause fungal disease.
By seed sown in spring at 13-18°C (55-64°F); by softwood cuttings in late spring; by semi-ripe cuttings in summer.
Leaves are picked before or during flowering and dried for infusions, liquid extracts, and tinctures; and for extractions of alkaloids.
Var. ocellatus
Has red-eyed flowers

Pacifica Series
Has a vigorous, compact, bushy habit, with large lilac, pale pink, or white, often red-eyed flowers.
Height: 30cm (12in)
Width: 30cm (12in)
30-60cm (12-24in)
30-60cm (12-24in)
Min. 13°C (55°F)
Parts Used:
All Above-Ground Parts, Leaves
Chemical Constituents:
  • Vinblastine
  • Vincristine
  • Vinleurosine
  • Virosidine
  • Properties:
    An astringent herb that reduces blood sugar levels, increasing perspiration, and stimulates the uterus.
    Known Effects:
  • Inhibits growth and development of germs
  • Depresses bone marrow production, damaging body's blood cell-manufacturing processes
  • Effective in treatment of several different types of malignant tumors
  • Reduces granulocytes (white blood cells) in body

  • Miscellaneous Information:
    When purified, derivatives of Vinca (vincristine sulfate, vinblastine sulfate) are used to treat cancer under rigidly controlled supervision.
    Possible Additional Effects:
  • May decrease inflammation when used as an ointment
  • May treat sore throats and inflamed tonsils
  • May treat diabetes mellitus
  • May cause halluncinations when smoked
  • Medicinal Uses:
    Internally for diabetes (West Indies); diabetes, hypertension, chronic constipation, and indigestion (Mauritius, Vietnam, Surinam); asthma (Bahamas); menstrual irregulation (Africa, Phillipines). Isolated alkaloids treat acute leukemia (especially in children), Hodgkin's disease, and other cancers, with side-effects such as nausea, hair loss, and bone marrow depression.
    Internally, it is used as a diuretic and to treat diabetes, cough, inflammation of the throat, and lung congestion. Externally, it is used for insect stings and bites, skin infection, skin inflammation, and eye irritation.
    Possible Side Effects:
    Madagascar periwinkle's side effects include nausea, vomiting, hair loss, vertigo, hallucinations, and seizures.
    Drug Interactions:
    Taking Madagascar periwinkle with these drugs may increase the risk of hypoglycemia (low blood sugar):
    Acarbose, (Prandase, Precose)
    Acetohexamide, (Acetohexamide)
    Chlorpropamide, (Diabinese, Novo-Propamide)
    Gliclazide, (Diamicron, Novo-Gliclazide)
    Glimepiride, (Amaryl)
    Glipizide, (Glucotrol)
    Glipizide and Metformin, (Metaglip)
    Gliquidone, (Beglynor, Glurenorm)
    Glyburide, (DiaBeta, Micronase)
    Glyburide and Metformin, (Glucovance)
    Insulin, (Humulin, Novolin R)
    Metformin, (Glucophage, Riomet)
    Miglitol, (Glyset)
    Nateglinide, (Starlix)
    Pioglitazone, (Actos)
    Repaglinide, (GlucoNorm, Prandin)
    Rosiglitazone, (Avandia)
    Rosiglitazone and Metformin, (Avandamet)
    Tolazamide, (Tolinase)
    Tolbutamide, (Apo-Tolbutamide, Tol-Tab)
    Lab Test Alterations:
    May lower blood glucose.
    Disease Effects:
    May cause hypoglycemia (low blood sugar).
    Warnings and Precautions:
    Toxic if eaten.

    Don't take if you:
  • Are pregnant, think you may be pregnant, or plan pregnancy in the near future.
  • Have any chronic disease of the gastrointestinal tract, such as stomach or duodenal ulcers, reflux esophagitis, ulcerative colitis, spastic colitis, diverticulosis, or diverticulitis.

  • Consult your doctor if you:
  • Take this herb for any medical problem that doesn't improve in 2 weeks (There may be safer, more effective treatments.)
  • Take any medicinal drugs or herbs including aspirin, laxatives, cold and cough remedies, antacids, vitamins, minerals, amino acids, supplements, other prescription or non-prescription drugs.

  • Pregnancy:
    Dangers outweigh any possible benefits. Don't use.
    Dangers outweigh any possible benefits. Don't use.
    Infants and Children:
    Treating infants and children under 2 with any herbal preparation is hazardous.
    This product will not help you and may cause toxic symptoms.
  • Store in cool, dry area away from direct light, but don't freeze.
  • Store safely out of reach of children.
  • Don't store in bathroom medicine cabinet. Heat and moisture may change the action of the herb.

  • Safe Dosage:
    Consult your doctor for the appropriate dose for your condition.
    Rated slightly dangerous, particularly in children, persons over 55 and those who take larger than appropriate quantities for extended periods of time.
    Adverse Reactions, Side Effects, or Overdose Symptoms:
    Signs and Symptoms What to Do

    Drowsiness Discontinue. Call doctor when convenient.
    Hair Loss Discontinue. Call doctor when convenient.
    Nausea Discontinue. Call doctor immediately.
    Seizures Seek emergency treatment.
    Yellow eyes, dark urine and yellow skin resulting from destruction of some liver cells Seek emergency treatment.
    Encyclopedia of Herbs by Deni Brown Copyright © 1995, 2001 Dorling Kindersley Limited. pp 158-159
    The Essential Herb-Drug-Vitamin Interaction Guide by Geo. T. Grossberg,MD and Barry Fox,PhD Copyright©2007 Barry Fox,PhD. Pg. 318
    Vitamins, Herbs, Minerals & Supplements The Complete Guide by H. Winter Griffith, MD Copyright©1998 Fisher Books pp. 411-412