Gymnema

Common names: Gurmarbooti, Gurmar

Botanical name: Gymnema sylvestre

Parts used and where grown: Gymnema sylvestre is a woody climbing plant that grows in the tropical forests of central and southern India. The leaves are used in herbal medicine preparations. G. sylvestre is known as periploca of the woods in English and meshasringi (meaning “ram’s horn”) in Sanskrit. The leaves, when chewed, interfere with the ability to taste sweetness, which explains the Hindi name gurmar—“destroyer of sugar.”

Gymnema has been used in connection with the following condition (refer to the individual health concern for complete information):

Rating Health Concerns
2Stars Diabetes
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star An herb is primarily supported by traditional use, or the herb or supplement has little scientific support and/or minimal health benefit.

Historical or traditional use (may or may not be supported by scientific studies): Gymnema has been used in India for the treatment of diabetes for over 2,000 years. The leaves were also used for stomach ailments, constipation, water retention, and liver disease.

Active constituents: The hypoglycemic (blood sugar-lowering) action of gymnema leaves was first documented in the late 1920s.1 This action is gradual in nature, differing from the rapid effect of many prescription hypoglycemic drugs. Gymnema leaves raise insulin levels, according to research in healthy volunteers.2 Based on animal studies, this may be due to regeneration of the cells in the pancreas that secrete insulin.3 Other animal research shows that gymnema can also improve uptake of glucose into cells and prevent adrenaline from stimulating the liver to produce glucose, thereby reducing blood sugar levels.4

The leaves are also noted for lowering serum cholesterol and triglycerides.5 While studies have shown that a water-soluble acidic fraction of the leaves provides hypoglycemic actions, the specific constituent responsible for this action has not been clearly identified. Some researchers have suggested gymnemic acid as one possible candidate.6 However, further research is needed to clearly determine which constituent is responsible for this effect. Gurmarin, another constituent of the leaves, and gymnemic acid have been shown to block the ability in humans to taste sweets.7

How much is usually taken? Double-blind clinical trials in India have used 400 mg per day of a water-soluble acidic fraction of the gymnema leaves. In type 2 diabetics, ongoing use for periods as long as 18 to 24 months has proven successful.8 In type 1 (insulin-dependent) diabetes patients, a similar amount has been used successfully as an adjunct to ongoing use of insulin.9 The extract used in these trials contains approximately 2,990 gymnemic acids. Consult closely with a physician, as insulin amounts may need to be lowered while taking gymnema. Traditionally, 2–4 grams per day of the leaf powder is used.

Are there any side effects or interactions? Used at the amounts suggested, gymnema is generally safe and devoid of side effects. The safety of gymnema during pregnancy and breast-feeding has not yet been determined. People with diabetes should only use gymnema to lower blood sugar under the clinical supervision of a healthcare professional. Gymnema cannot be used in place of insulin to control blood sugar by people with either type 1 or type 2 diabetes.

Are there any drug interactions? Certain medications may interact with gymnema. Refer to the drug interactions safety check for a list of those medications.

References:

1. Mhasker KS, Caius JF. A study of Indian medicinal plants. II. Gymnema sylvestre R.Br. Indian J Med Res Memoirs 1930;16:2–75.

2. Shanmugasundaram KR, Panneerselvam C, Sumudram P, Shanmugasundaram ERB. Insulinotropic activity of G. sylvestre, R.Br. and Indian medicinal herb used in controlling diabetes mellitus. Pharmacol Res Commun 1981;13:475–86.

3. Shanmugasundaram ER, Gopinath KL, Radha Shanmugasundaram K, Rajendran VM. Possible regeneration of the islets of Langerhans in streptozotocin diabetic rats given Gymnema sylvestre leaf extracts. J Ethnopharmacol 1990;30:265–79.

4. [No authors listed]. Gymnema sylvestre. Alt Med Rev 1999;4:46–7 [review].

5. Bishayee A, Chatterjee M. Hypolipidemic and antiatherosclerotic effects of oral Gymnema sylvestre R.Br. leaf extract in albino rats fed on a high fat diet. Phytother Res 1994;8:118–20.

6. Gymnema monograph. Lawrence Review of Natural Products. Aug 1993.

7. Fushiki T, Kojima A, Imoto T, et al. An extract of Gymnema sylvestre leaves and purified gymnemic acid inhibits glucose-stimulated gastric inhibitory peptide secretion in rats. J Nutr 1992;122:2367–73.

8. Baskaran K, Ahmath BK, Shanmugasundaram KR, Shanmugasundaram ERB. Antidiabetic effect of a leaf extract from Gymnema sylvestre in non-insulin-dependent diabetes mellitus patients. J Ethnopharmacol 1990;30:295–305.

9. Shanmugasundaram ERB, Rajeswari G, Baskaran K, et al. Use of Gymnema sylvestre leaf extract in the control of blood glucose in insulin-dependent diabetes mellitus. J Ethnopharmacol 1990;30:281–94.