Gymnema sylvestre: does it really curb sugar cravings?

In India, it is called “gurmar”, the sugar destroyer. Let a little Gymnema sylvestre dissolve on your tongue, then taste a square of chocolate: the sweetness has almost disappeared. This striking experience made the plant famous. But is blocking sweet taste for a few dozen minutes the same as curbing sugar cravings? Mechanisms, human studies, blood glucose, risks and doses studied: here is what science can establish, and what it cannot.

What is Gymnema sylvestre?

Gymnema sylvestre is a climbing plant in the Apocynaceae family (previously classified as Asclepiadaceae). It grows in tropical and subtropical areas of Africa, Arabia, India, Sri Lanka and Southeast Asia, as far as Australia. Its leaves have long been used in Ayurvedic medicine, and its Hindi name, “gurmar”, literally means “sugar destroyer”.

Its main active compounds are gymnemic acids, molecules in the triterpene saponin family. Extracts sold as supplements are often standardised to a gymnemic acid content, for example 25%.

How does gymnema block sweet taste?

Sweet taste is detected on the tongue by a receptor made of two proteins, T1R2 and T1R3. A 2014 study showed that gymnemic acids block the human receptor by binding to the part of T1R3 that crosses the membrane of taste cells. Interestingly, they do not act on the mouse receptor, and simply rinsing the mouth with a cyclodextrin is enough to remove the blockade.

Gymnema also contains a small peptide, gurmarin. It blocks sweet taste in rats, but does not act on the human receptor: in humans, the effect comes from gymnemic acids.

Does it really curb sugar cravings? What studies show

Does blocking the perception of sweetness reduce consumption? Several trials have tested lozenges containing gymnemic acids.

• In the short term, the effect is clear. In 56 adults, a lozenge containing 4mg of gymnemic acids reduced the amount of chocolate consumed in the following fifteen minutes by 21%, desire by 23% and pleasure by 31%, without changing hunger. In a randomised trial involving 67 adults, a single lozenge reduced sweet consumption by 44%. A brain imaging study even observed lower activation in reward regions when anticipating drinking a milkshake.
• Over time, the effect fades. In a 14-day double-blind randomised trial (58 participants, one lozenge three times a day), chocolate consumption was lower on day one, but the difference had disappeared by day fifteen. In another trial, participants who drank gymnema tea subsequently sought more sugar, as though compensating.
• More favourable findings also exist: in 2025, among 32 people who described themselves as having a “sweet tooth”, unrestricted lozenge use reduced sugary drink consumption by 42% and cravings by 28% compared with placebo.

These studies remain small, often short, and some were funded by lozenge manufacturers.

Our verdict: yes, but on individual occasions. In contact with the tongue, gymnema makes sweets less enjoyable and leads to less being eaten in the following hour. It can help interrupt a particular craving, but is not a lasting solution on its own.

Capsule, tea or lozenge: the form makes all the difference

Gymnema acts in two very different ways depending on whether it touches the tongue.

• In contact with the tongue (lozenge, tea or powder): it blocks the perception of sweet taste for a limited time. This sensory effect may be useful just before a tempting situation.
• Swallowed in a capsule: it does not touch the tongue, so it does not alter taste. Studies on blood glucose and metabolism, by contrast, used swallowed extracts.

The tea has a strongly bitter taste, and its active compound content is difficult to estimate. Capsules of standardised extract, such as Hexagon® Gymnema Sylvestre (400mg of extract standardised to 25% gymnemic acids per capsule), allow you to know precisely what you are taking. To understand the different formats, read our article on capsule forms and functions.

Gymnema and blood glucose: encouraging but limited results

Gymnema's antidiabetic reputation first arose from older, less rigorous studies. In 1990, adding a leaf extract (400mg per day for 18 to 20 months) to the treatment of 22 people with type 2 diabetes was associated with lower fasting blood glucose and glycated haemoglobin (HbA1c), but the study was neither randomised nor blinded. In 2010, an extract stimulated insulin secretion from human pancreatic islets in the laboratory and increased insulin in a small series of patients.

Recent randomised trials are more robust, but tiny:

• among 30 people with impaired glucose tolerance assigned to gymnema or placebo, 600mg per day was associated in the gymnema group with lower blood glucose two hours after a glucose load (from 9.1 to 7.8 mmol/L) and lower HbA1c (from 5.8 to 5.4%);
• among 24 people with metabolic syndrome, the same dose for 12 weeks changed neither insulin secretion nor insulin sensitivity.

Two meta-analyses suggest an effect on fasting blood glucose and blood lipids (triglycerides and cholesterol), but the studies were heterogeneous, of low quality, and one analysis did not compare against placebo. Gymnema is therefore no substitute for medical care. For another plant studied for glucose metabolism, see our article on berberine.

Gymnema sylvestre for weight loss: what should you take away?

The evidence is thin. In the 12-week metabolic syndrome trial, mean weight in the gymnema group fell from 81.3 to 77.9 kg, with a reduction in BMI. However, this involved only 24 participants, with no effect on insulin, and the 2023 meta-analysis pooling six randomised trials reported no effect on weight. By occasionally helping people resist sweets, gymnema may support a change in habits; it does not cause weight loss on its own.

Which doses have been studied?

There is no official dose. Metabolism trials used 400mg to 1 g of extract per day; for the taste effect, a few milligrams of gymnemic acids in contact with the tongue are sufficient. Follow the manufacturer's recommended dose.

Risks, side effects and contraindications

• Hypoglycaemia: combined with diabetes medication, gymnema can lower blood glucose too much. In France, the label must specify that use is not recommended in people taking diabetes medication. In that situation, do not take it without your doctor's advice.
• Liver: a case of toxic hepatitis was published in 2010 in a 60-year-old woman drinking gymnema tea, with recovery within six months. The NIH LiverTox database classifies it as a possible rare cause of liver injury.
• Digestive symptoms: nausea, abdominal discomfort, diarrhoea and headaches are the most frequently reported adverse effects, usually temporary.
• Pregnancy and breastfeeding: no data are available; it is better to avoid it.

Other ways to address sugar cravings

Gymnema acts on taste, but sugar cravings have other drivers that can be addressed.

• Sleep. In 12 young men, two nights of four hours' sleep reduced leptin, the satiety hormone, by 18% and increased appetite for carbohydrate-rich foods by 33 to 45%. See our article on disrupted sleep.
• Stress. In the laboratory, women whose cortisol responded most strongly to stress subsequently ate more, particularly sweet foods. Find some approaches in our selection of 5 ingredients studied for stress.
• Habit. After three months of a diet low in simple sugars, participants perceived sweet foods as sweeter than before: the palate readjusts.

Frequently asked questions

What does “gurmar” mean?

It is the Hindi name for Gymnema sylvestre. It means “sugar destroyer” and refers to the leaf's effect on sweet taste, not an action on blood sugar.

How long does the effect on sweet taste last?

After a mouth rinse with gymnemic acids, sweet perception falls to around 14% of normal, then rises to 63% within 30 minutes. Full recovery takes more than 50 minutes, sometimes several hours.

When should you take Gymnema sylvestre?

For the taste effect, just before a tempting situation (after a meal or before a snack). For capsules, at the time recommended by the manufacturer, often with a meal.

Gymnema sylvestre or berberine: what is the difference?

These are two plants with two different mechanisms. Gymnema acts primarily on sweet taste; berberine is an alkaloid extracted from plants in the Berberis genus, studied for its effects on glucose metabolism. They are not interchangeable.

Is gymnema authorised in France?

Yes. The leaf appears on the list of plants authorised in food supplements (order of 24 June 2014), under its other botanical name, Marsdenia sylvestris. However, no health claim is authorised for this plant at European level.

Can you take gymnema if you have diabetes?

Not without medical advice. The risk of hypoglycaemia when combined with diabetes medication justifies the mandatory label warning, and gymnema does not replace any treatment.

Conclusion

Gymnema sylvestre earns its nickname in the literal sense: in contact with the tongue, it blocks the sweet taste receptor and leads to less sweet food being eaten in the following hour. Over several weeks, the effect on sugar cravings is less clear, and its promising action on blood glucose still rests on small studies. Used occasionally, with awareness of its limitations and precautions, it may help regain control over sweet cravings, particularly alongside better sleep and a gradual reduction in sugar.

Sources

1. Sanematsu K et al. (2014). Molecular mechanisms for sweet-suppressing effect of gymnemic acids. Journal of Biological Chemistry, 289(37), 25711-25720. doi:10.1074/jbc.M114.560409
2. Sigoillot M, Brockhoff A, Meyerhof W, Briand L (2012). Review of sweet taste-suppressing compounds. Applied Microbiology and Biotechnology, 96(3), 619-630. doi:10.1007/s00253-012-4387-3
3. Rayo-Morales R et al. (2023). Systematic review of gymnema and sweet taste perception. Heliyon, 9(10), e19733. PubMed 37817998
4. Gent JF, Hettinger TP, Frank ME, Marks LE (1999). Taste confusions following gymnemic acid rinse. Chemical Senses, 24(4), 393-403. doi:10.1093/chemse/24.4.393
5. Turner S et al. (2020). Consuming Gymnema sylvestre Reduces the Desire for High-Sugar Sweet Foods. Nutrients, 12(4), 1046. doi:10.3390/nu12041046
6. Turner S et al. (2022). A 14-day randomised trial of a Gymnema sylvestre lozenge and sweet food consumption. Nutrients, 14(24), 5287. PubMed 36558446
7. Stice E, Yokum S, Gau JM (2017). Gymnemic acids lozenge reduces short-term consumption of high-sugar food: A placebo controlled experiment. Journal of Psychopharmacology, 31(11), 1496-1502. doi:10.1177/0269881117728541
8. Stice E, Yokum S (2018). Effects of gymnemic acids lozenge on reward region response to receipt and anticipated receipt of high-sugar food. Physiology & Behavior, 194, 568-576. doi:10.1016/j.physbeh.2018.07.012
9. Noel et al. (2017). Study of gymnema tea and sugar-seeking behaviour. Appetite, 117, 74-81. PubMed 28606563
10. Hsiao WH et al. (2025). Trial of unrestricted gymnema lozenge use in people attracted to sugar. Appetite, 207, 107871. PubMed 39855349
11. Baskaran K et al. (1990). Antidiabetic effect of a leaf extract from Gymnema sylvestre in non-insulin-dependent diabetes mellitus patients. Journal of Ethnopharmacology, 30(3), 295-300. doi:10.1016/0378-8741(90)90108-6
12. Al-Romaiyan A et al. (2010). A novel Gymnema sylvestre extract stimulates insulin secretion from human islets in vivo and in vitro. Phytotherapy Research, 24(9), 1370-1376. doi:10.1002/ptr.3125
13. Zuñiga LY, González-Ortiz M, Martínez-Abundis E (2017). Effect of Gymnema sylvestre Administration on Metabolic Syndrome, Insulin Sensitivity, and Insulin Secretion. Journal of Medicinal Food, 20(8), 750-754. doi:10.1089/jmf.2017.0001
14. Gaytán Martínez LA et al. (2021). Effect of Gymnema sylvestre Administration on Glycemic Control, Insulin Secretion, and Insulin Sensitivity in Patients with Impaired Glucose Tolerance. Journal of Medicinal Food, 24(1), 28-32. doi:10.1089/jmf.2020.0024
15. Devangan S et al. (2021). The effect of Gymnema sylvestre supplementation on glycemic control in type 2 diabetes patients: A systematic review and meta-analysis. Phytotherapy Research, 35(12), 6802-6812. doi:10.1002/ptr.7265
16. Zamani M et al. (2023). The effects of Gymnema Sylvestre supplementation on lipid profile, glycemic control, blood pressure, and anthropometric indices in adults: A systematic review and meta-analysis. Phytotherapy Research, 37(3), 949-964. doi:10.1002/ptr.7585
17. Shiyovich A, Sztarkier I, Nesher L (2010). Toxic hepatitis induced by Gymnema sylvestre, a natural remedy for type 2 diabetes mellitus. The American Journal of the Medical Sciences, 340(6), 514-517. doi:10.1097/MAJ.0b013e3181f41168
18. NIH, LiverTox (2024). Gymnema. ncbi.nlm.nih.gov
19. Order of 24 June 2014 establishing the list of plants, other than fungi, authorised in food supplements and the conditions of their use (Official Journal of the French Republic).
20. Spiegel K, Tasali E, Penev P, Van Cauter E (2004). Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of Internal Medicine, 141(11), 846-850. doi:10.7326/0003-4819-141-11-200412070-00008
21. Epel E, Lapidus R, McEwen B, Brownell K (2001). Stress may add bite to appetite in women: a laboratory study of stress-induced cortisol and eating behavior. Psychoneuroendocrinology, 26(1), 37-49. doi:10.1016/S0306-4530(00)00035-4
22. Wise PM, Nattress L, Flammer LJ, Beauchamp GK (2016). Reduced dietary intake of simple sugars alters perceived sweet taste intensity but not perceived pleasantness. The American Journal of Clinical Nutrition, 103(1), 50-60. doi:10.3945/ajcn.115.112300

Food supplements do not replace a varied, balanced diet or a healthy lifestyle. Ask a healthcare professional for advice if you are taking medication, pregnant or breastfeeding.