Gymnema sylvestreGurmar, 'sugar destroyer'
An Ayurvedic leaf extract with a handful of small trials showing lower fasting glucose and HbA1c in type 2 diabetics, plus a well-documented effect of blunting sweet taste for about an hour after chewing it.
- Dose used in trials
- 200 to 400 mg/day of GS4 or a 25 percent gymnemic acid extract
- Time to effect
- Sweet-taste effect is immediate; glycemic effects took months in the trials
What the evidence says
Two often-cited Indian trials from 1990 (GS4 extract, 400 mg/day for 18 to 20 months) found HbA1c reductions in both type 1 and type 2 diabetics on top of medication. Later trials are small and mixed. The sweet-taste suppression is well established and is the basis of its use for cravings.
What it is
A woody climbing vine from India whose leaves contain gymnemic acids. These block sweet receptors on the tongue, and are proposed to reduce sugar absorption in the gut and support insulin release.
What the trials found
The 1990 trials are the strongest, with HbA1c falling by roughly two points over 18 months in patients who continued medication. They were small, open-label and have not been replicated at that scale. Modern short trials show smaller or inconsistent effects.
The practical use most people notice is craving control: chew a leaf or take a lozenge and sweet foods taste flat for an hour.
Side effects
- Generally well tolerated
- Hypoglycemia when combined with diabetes medication
Interactions
- Insulin and oral diabetes drugs: additive effect, monitor glucose
- May reduce absorption of some drugs if taken at the same time; separate by two hours
Products we reviewed that contain it
- GlucoTrust review →
Bedtime blood sugar capsule with gymnema, chromium, cinnamon and a sleep blend. Dose of gymnema sylvestre not disclosed on the label.
Frequently asked questions
- Is gymnema in GlucoTrust at a useful dose?
- The label does not say. The trials used 400 mg a day of a standardized extract; a proprietary blend capsule that also holds seven other ingredients is unlikely to.
Other blood sugar ingredients
This article is for information only and is not medical advice. Statements about supplements have not been evaluated by the FDA. Do not start, stop or combine supplements with prescription medication without talking to your doctor or pharmacist. If you cannot pass urine, or have chest pain, confusion or fainting, seek emergency care.
Some links on this site are affiliate links, including links to ClickBank vendors. If you click one and buy something, we may earn a commission at no extra cost to you. This site is not affiliated with or endorsed by Google, Meta, or any product manufacturer mentioned here.