Moderate evidenceHeart & metabolic

Salacia

Salacia is an alpha-glucosidase inhibitor from South Asian traditional medicine with a genuine, reproducible effect on post-meal glucose and a small HbA1c benefit in randomised trials — roughly a 0.25-0.5% drop, comparable to a weak acarbose. The trade-off is acarbose-like gas and bloating.

What the science says

Blunts post-meal glucose spikes Moderate evidence
Salacia's mangiferin and salacinol/kotalanol inhibit intestinal alpha-glucosidase, and multiple crossover trials in healthy and prediabetic adults show reduced postprandial glucose and insulin after a carbohydrate load, with a matching rise in breath hydrogen confirming carbohydrate reaches the colon undigested. The mechanism is real and well characterised.
Lowers HbA1c in type 2 diabetes Moderate evidence
A triple-blind, placebo-controlled crossover trial in 136 Sri Lankan patients with type 2 diabetes found a Salacia reticulata biscuit reduced HbA1c by about 0.25% relative to placebo (from a baseline of roughly 8.5%), significant but small. Earlier RCTs in prediabetes reported HbA1c and lipid improvements of similar magnitude. This is a modest adjunct effect, not a substitute for metformin.
Improves cholesterol Limited evidence
A double-blind RCT in prediabetic adults with mild-to-moderate hyperlipidaemia reported improvements in total and LDL cholesterol and triglycerides alongside glycaemic changes, but this has not been consistently replicated and the lipid effects are secondary findings in glucose trials.

Dosage & safety

Studied doseTrials have used 240-1000 mg/day of Salacia reticulata or S. oblonga extract, taken immediately before carbohydrate-containing meals — timing matters, because the mechanism is enzyme inhibition in the gut. Acute postprandial studies used 240-1000 mg with the meal; the HbA1c trials ran 6 weeks to 3 months.

SafetySide effects mirror acarbose and are common: flatulence, abdominal distension, borborygmi, nausea and loose stools, driven by fermentation of undigested carbohydrate. Trials found no serious renal or hepatic adverse effects. Because it lowers glucose it can compound hypoglycaemia risk with insulin or sulfonylureas — although as a carbohydrate-blocker its own hypoglycaemia risk is low. Avoid in pregnancy and breastfeeding for lack of data. Salacia species are variably identified and adulterated in the supplement trade, so extract identity and standardization are worth checking.

Scientific references

Salacia reticulata improves serum lipid profiles and glycemic control in patients with prediabetes and mild to moderate hyperlipidemia: a double-blind, placebo-controlled, randomized trial
Shivaprasad HN, Bhanumathy M, Sushma G, Midhun T, Raveendra KR, Sushma KR, Venkateshwarlu K — Journal of Medicinal Food, 2013
The Effect of Salacia Reticulata Extract Biscuits on Blood Sugar Control of Type 2 Diabetes Mellitus Patients: A Two-Period, Two-Sequence, Crossover, Randomized, Triple-Blind, Placebo-Controlled, Clinical Trial
Siribaddana S, Medagama A, Wickramasinghe N, Siribaddana NM, Agampodi S, Fernando D — Cureus, 2023

Where to buy

View on iHerb

Referral link — this site may earn a commission on purchases.

Related in Heart & metabolic

Vitamin B3 (Niacin) Limited evidence
Vitamin K2 (MK-7) Limited evidence
Chromium Limited evidence
Potassium Strong evidence
Vanadium Limited evidence
L-Arginine Moderate evidence