Salacia reticulata
Summary
Salacia reticulata extracts contain salacinol and kotalanol, which block carbohydrate-digesting enzymes in the gut. A 51-person crossover lowered HbA1c in type 2 diabetes, a 29-person trial lowered fasting glucose and LDL in prediabetes, and a 133-person trial found a small fat-mass loss but no change in body-fat percentage. Related Salacia species blunted post-meal glucose.
Key facts
- A woody climber used in Sri Lankan and Indian traditional medicine; its tea is known as kothala himbutu[3][4]
- Salacinol and kotalanol, measured at about 4.2 and 2.3 µg/mg in one trial extract[4]
- HbA1c was 6.29% after 3 months of the tea versus 6.65% after placebo in 51 patients[3]
- 12 weeks lowered fat mass by about 480 g more than placebo, but body-fat percentage did not differ[1]
- Salacia oblonga cut post-meal glucose and insulin in a 66-person crossover; a Salacia chinensis trial mainly lowered the insulin response. These are different plants[5][6]
- 4 graded human outcomes on this page
- October 13, 2026
How it works
ProposedSalacia compounds (salacinol, kotalanol) inhibit intestinal alpha-glucosidase enzymes that break down sugars and starch, slowing glucose absorption, the same action as the drug acarbose. Undigested carbohydrate reaching the colon may also shift gut bacteria. In humans this is supported indirectly by lower post-meal glucose and insulin with related Salacia species.[4][5][6]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Weight | Grade C | Mixed | RCT · n = 133 · 2026 | 1 row |
| Blood sugar | Grade C | Improved | Crossover RCT · n = 51 · 2005 | 2 rows |
| Immunity | Grade D | Improved | RCT · n = 32 · 2015 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Body fat mass and body-fat percentage | Mixed | Grade C | RCT · n = 133 · 2026 Adults with overweight or obesity Form: Standardised Salacia reticulata extract capsules · Dose: Twice daily (mg dose not stated in the abstract) · Duration: 12 weeks Fat mass fell by about 482 g more than placebo (95% CI −907 to −58 g), but the co-primary outcome, body-fat percentage, did not differ (−0.30%, p=0.145). | 42187323 (opens PubMed)Source [1] |
| HbA1c in type 2 diabetes | Improved | Grade C | Crossover RCT · n = 51 · 2005 Adults with stable type 2 diabetes on usual treatment Form: Kothala himbutu herbal tea (Salacia reticulata) · Dose: Standard tea preparation · Duration: 3 months active, 3 months placebo HbA1c after the tea was 6.29% versus 6.65% after placebo (p=0.008); glibenclamide doses fell slightly with the tea (p=0.07). | 15707755 (opens PubMed)Source [3] |
| T-cell proliferation and gut microbiota | Improved | Grade D | RCT · n = 32 · 2015 Healthy Japanese adults with low immune-strength scores Form: Salacia reticulata extract tablets · Dose: 240 mg/day (60 mg before breakfast and lunch, 120 mg before dinner) · Duration: 4 weeks T-cell proliferation rose versus placebo; faecal Bifidobacterium increased and Clostridium decreased; no adverse events attributed to the extract. | 26630568 (opens PubMed)Source [4] |
| Fasting glucose and LDL in prediabetes with high lipids | Improved | Grade D | RCT · n = 29 · 2013 Adults with prediabetes and mild to moderate hyperlipidaemia Form: Salacia reticulata leaf or root-bark extract · Dose: 500 mg/day · Duration: 6 weeks Root-bark extract lowered LDL and fasting glucose at weeks 3 and 6; leaf extract lowered fasting glucose at week 6 only; no adverse events. | 23767865 (opens PubMed)Source [2] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Salacia reticulata extract (root, stem or leaf) | Varies[1][2][3][4] | No human absorption data; it acts mainly in the gut.[4] | No adverse events were reported in the cited trials of up to 12 weeks.[1][2][4] | Diabetes, prediabetes, weight and immune trials |
| Kothala himbutu tea | Varies[3] | No human absorption data.[3] | All 51 patients completed both arms; liver and kidney tests were monitored.[3] | 3-month type 2 diabetes crossover trial |
Studied doses
Doses studied in human trials ranged from 240 mg/day (4 weeks) to 500 mg/day (6 weeks) of Salacia reticulata extract. A 12-week weight trial gave capsules twice daily without a dose stated in the abstract, and a diabetes trial used a standard herbal tea for 3 months.[1][2][3][4]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Diabetes medicinesRCTSalacia lowered HbA1c in people on diabetes drugs, and glibenclamide doses fell slightly during use, so effects on blood sugar may add up.[3]
Who should be careful
- People on diabetes medicines
- Because it lowered HbA1c in people with type 2 diabetes already on medication, blood sugar may need closer monitoring when it is added to glucose-lowering drugs.[3]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Check the speciesMany products use Salacia oblonga or Salacia chinensis. Their post-meal glucose trials do not transfer automatically to Salacia reticulata, and vice versa.[5][6]
- Timing with mealsThe enzyme-blocking action works on carbohydrate in the gut; trials gave the extract before meals or with a sugar or carbohydrate load.[4][5][6]
- Gas and bloatingIn a Salacia oblonga trial, breath hydrogen rose with dose, a sign that undigested carbohydrate was fermenting in the colon, the same process behind the gas seen with acarbose-type drugs.[7]
Cost per studied dose, without the sales pitch
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Cost per studied dose
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Frequently asked questions
Does Salacia reticulata lower blood sugar?
Small trials suggest so: a 3-month crossover in 51 people with type 2 diabetes lowered HbA1c (6.29% vs 6.65%), and a 6-week trial in 29 people with prediabetes lowered fasting glucose.[2][3]
How does it work?
It blocks gut enzymes that digest sugars and starch, slowing glucose absorption after meals.[4][5]
Does it help with weight loss?
Only slightly. In 133 adults, 12 weeks reduced fat mass by about 480 g more than placebo, but body-fat percentage did not change significantly.[1]
Is Salacia oblonga the same thing?
No. It is a related species with its own trials showing lower post-meal glucose and insulin in type 2 diabetes.[5]
Sources
- [1]A 12-Week Randomized, Double-Blind, Placebo-Controlled Trial of Salacia reticulata Extract for Fat-Mass Reduction in Adults with Overweight/Obesity.. J Med Food, 2026. RCT
- [2]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.. J Med Food, 2013. RCT
- [3]A double blind randomised placebo controlled cross over study of a herbal preparation containing Salacia reticulata in the treatment of type 2 diabetes.. J Ethnopharmacol, 2005. crossover-RCT
- [4]Improvement in Human Immune Function with Changes in Intestinal Microbiota by Salacia reticulata Extract Ingestion: A Randomized Placebo-Controlled Trial.. PLoS One, 2015. RCT
- [5]Extract of Salacia oblonga lowers acute glycemia in patients with type 2 diabetes.. Am J Clin Nutr, 2007. crossover-RCT
- [6]Salacia Extract Improves Postprandial Glucose and Insulin Response: A Randomized Double-Blind, Placebo Controlled, Crossover Study in Healthy Volunteers.. J Diabetes Res, 2016. crossover-RCT
- [7]Effects of a medical food containing an herbal alpha-glucosidase inhibitor on postprandial glycemia and insulinemia in healthy adults.. J Am Diet Assoc, 2005. crossover-RCT
What changed
- Independent adversarial review: corrected the related-species key fact (the Salacia chinensis trial lowered post-meal insulin, not clearly glucose), added a gas/bloating note from breath-hydrogen data, and added industry-authorship notes. All PMIDs re-verified; the salacinol and kotalanol figures were confirmed in the full text.
- Adversarial second pass: every PMID re-checked against NCBI esummary (title, year, no retraction, erratum or expression-of-concern flags) and every number in each evidence row re-read against its PubMed abstract (PMC full text where the abstract lacked dose or duration). Countries and funding notes kept only where the abstract or full text states them; interactions listed only where a source supports them, otherwise stated as unstudied.
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows.