Herb & supplement monograph

Neem Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Neem interacts with medications. The heart of this page is the interaction list — every drug Neem is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Neem is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Neem Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Neem drug interaction appears low for most people, though a few situations deserve real attention. None of the listed interactions are rated major, and while all carry a moderate rating, nearly all rest on lab or animal findings rather than confirmed effects in people.

Interactions deserving the most attention

The clearest concern involves diabetes medications. Clinical research shows neem can lower blood sugar in adults with type 2 diabetes, including people already taking metformin, so combining them could push blood sugar too low. We would also be cautious with immunosuppressants, because animal research suggests neem may stimulate the immune system and could work against these medicines, which matters greatly for transplant patients whose drug effects must stay steady.

What the rest of the list means

The long list of interacting medications looks alarming, but most entries come from lab studies suggesting neem might affect enzymes and a transporter the body uses to clear many drugs. So far, these predicted effects have not been reported in people, so most combinations are theoretical rather than proven problems.

Check your medications against Neem

Based on HelloPharmacist’s Neem interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Neem

1014 medications have a known interaction with Neem, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Neem using our pharmacist-reviewed interaction data.

AI summaries are generated from our Neem interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Neem combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Neem affects

Every type of medication (drug category) Neem is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 7 drug categories Neem interacts with

Antidiabetes DrugsCytochrome P450 1a2 (cyp1a2) SubstratesCytochrome P450 2c8 (cyp2c8) SubstratesCytochrome P450 2c9 (cyp2c9) SubstratesCytochrome P450 3a4 (cyp3a4) SubstratesImmunosuppressantsP-glycoprotein Substrates

Antidiabetes Drugs

Neem might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Some clinical research shows that neem can lower blood glucose levels in adults with type 2 diabetes, including those already taking metformin.

Likelihood Possible Evidence D

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, neem leaf extract might increase the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that neem leaf extract inhibits CYP1A2 enzymes. So far, this reaction has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2C8 (Cyp2C8) Substrates

Theoretically, neem leaf extract might increase the levels and clinical effects of CYP2C8 substrates.
In vitro research shows that neem leaf methanol extract inhibits CYP2C8 enzymes. So far, this reaction has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, neem leaf extract might increase the levels and clinical effects of CYP2C9 substrates.
In vitro research shows that neem leaf methanol extract inhibits CYP2C9 enzymes. So far, this reaction has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, neem leaf extract might increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that neem leaf methanol extract inhibits CYP3A4 enzymes. So far, this reaction has not been reported in humans.

Likelihood Possible Evidence D

Immunosuppressants

Theoretically, neem might decrease the effectiveness of immunosuppressants.
Animal research suggests that neem might have immunostimulant effects.

Likelihood Possible Evidence D

P-Glycoprotein Substrates

Theoretically, neem leaf extract might increase the levels and clinical effects of P-glycoprotein substrates.
In vitro research shows that neem leaf methanol extract inhibits renal P-glycoprotein transport activity. So far, this reaction has not been reported in humans.

Likelihood Possible Evidence D

Monograph

Neem: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Neem is a tree from India used for centuries in traditional medicine, especially for skin, dental, and antimicrobial purposes. Some small studies are promising for oral health and skin, but high-quality human evidence is limited for most uses. Neem oil and seed extracts can be toxic if swallowed, especially in children, so use with caution and talk to your pharmacist or doctor first.

Scientific name: Azadirachta indica
Family: Meliaceae
Part used: Leaves, seeds (and seed oil), bark, and twigs
Common forms: Capsules, leaf powder, leaf extract, tea, topical oil, toothpaste, mouth rinse, and soap

People commonly use it for

Skin conditions
Dental and gum health
Antimicrobial and antiparasitic
Digestive upset
Blood sugar support
Insect repellent/pesticide

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Leaf preparations are likely safe short-term for most adults, but neem oil and seed extracts can be toxic if swallowed.

PregnancyLikely Unsafe

When neem oil or leaf is used orally. Neem oil and leaf have been used as abortifacients.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Neem (Azadirachta indica) is a fast-growing evergreen tree native to India and now grown across many tropical and subtropical regions. Nearly every part of the tree — the leaves, seeds, bark, and twigs — has been used in traditional Indian (Ayurvedic) medicine for thousands of years.

People use neem in many forms. The leaves are made into teas, powders, and capsules. The seeds are pressed to make neem oil, which is applied to the skin or used as a natural pesticide. Twigs have traditionally been chewed as natural toothbrushes, and neem is a common ingredient in some toothpastes, mouth rinses, and soaps.

Neem is also well known outside of medicine as a plant-based insecticide. In fact, neem oil is registered for use as a pesticide with the U.S. Environmental Protection Agency (EPA).

How it works

Neem contains many active plant compounds, including azadirachtin, nimbin, nimbidin, and various flavonoids and other antioxidants. These compounds are thought to give neem its antimicrobial, anti-inflammatory, and antioxidant effects.

In laboratory studies, neem extracts appear to interfere with the growth of certain bacteria, fungi, and parasites and to reduce inflammation. Azadirachtin is the main compound behind neem's well-known insecticide activity, disrupting the life cycle of many insects.

It is important to remember that most of this information comes from test-tube and animal research. How well these effects apply to the human body, and at what doses, is still not fully understood.

Effectiveness

Does Neem work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 23 uses evaluated

3 Possibly effective 20 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Possibly Effective Dental plaque