The short answer
Yes, there is evidence that neem adds to metformin. In a 12-week placebo-controlled trial, 80 adults with type 2 diabetes already on metformin took a standardised extract of neem leaves and twigs or a placebo. In the highest-dose group, fasting sugar went from 120.7 to 97.3 mg/dL and HbA1c from 7.78% to 6.26%. No low-sugar episodes were reported.
The trial was small and short, and nobody in it took insulin. Neem oil and home-made preparations are different products from the extract tested. If you take metformin or insulin and want to start neem, tell your doctor and ask whether you should check your sugar more often.
Metformin is sold in India as Glycomet. Common insulins include Actrapid and Lantus.
At a glance
| What was seen | How it may work | Direction | Evidence |
|---|---|---|---|
| Lower fasting sugar and HbA1c when neem extract was added to metformin[1] | Extra sugar lowering; how is not established | Sugar falls further; insulin not studied | RCT |
No listing is not a clearance. A missing interaction here never means a combination is safe.
The evidence, study by study
Trial in type 2 diabetes on metformin, 2020 RCT
Eighty adults on 1,500 to 2,500 mg of metformin a day took a standardised water extract of neem leaves and twigs (125, 250 or 500 mg twice a day) or a placebo for 12 weeks. With the highest dose, fasting sugar fell from 120.7 to 97.3 mg/dL and HbA1c from 7.78% to 6.26%. These are changes within that group, not differences from placebo. No low-sugar episodes were reported and two people had mild stomach complaints. The authors note the small size, the short length and that diet and exercise were not tracked.[1]
What your doctor may watch for
- Blood sugar readings after you add neem.[1]
- Sweating, shakiness or confusion, which should be reported to your diabetes team promptly, especially if you use insulin.
What to tell your prescribing doctor
You can read this out, or show them this page:
“I am taking, or planning to take, neem (leaf powder, capsules, extract or juice, and how much) along with my diabetes medicine. In a trial, a neem extract lowered sugar further in people on metformin. Should I check my sugar more often, and what reading should make me call you?”
Withheld until review
Questions people ask
Can neem cause low sugar with metformin?
None was reported in the 12-week trial. The metformin label says metformin by itself does not usually cause low sugar, but people on insulin were not studied with neem.[1][2]
Is neem juice the same as the extract in the trial?
No. The trial used a standardised water extract of leaves and twigs. Leaves, bark, juice and neem oil are different products, and results for one do not carry over to another.[1]
Related
Karela (bitter gourd) and diabetes medicines
Added to metformin and dapagliflozin, a karela extract lowered HbA1c further in a 2026 study. With insulin or sulfonylureas, low sugar is the worry.
ConditionType 2 diabetes (sugar): what Ayurveda offers
Some herbs, such as methi and karela, lowered HbA1c a little in trials. Taken with diabetes medicines, they can add to the risk of low sugar.
InteractionFenugreek (methi) with metformin or insulin
Methi lowered blood sugar further when added to diabetes medicines in two trials. How often that causes low sugar was not measured well.
InteractionNeem and blood pressure medicines
Neem lowered blood pressure in rats, and in lab tests it blocked an enzyme that clears amlodipine. We found no study of neem with BP medicines.
Sources
- Pingali U, Ali MA, Gundagani S, Nutalapati C. Evaluation of the effect of an aqueous extract of Azadirachta indica (neem) leaves and twigs on glycemic control, endothelial dysfunction and systemic inflammation in subjects with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled clinical study. Diabetes Metab Syndr Obes. 2020;13:4401-4412. PMID 33244247.
- Metformin hydrochloride tablets, US prescribing information (DailyMed).
Awaiting review by The Good Vaidya Medical Board. Prepared from the sources below and checked against each one.
Published 4 November 2026 · Last updated 4 November 2026
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