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Herb library · Updated 12 November 2026 · By Aashish Passi · 30 sources

Neem (Azadirachta indica): what the research says

Neem is Azadirachta indica A.Juss., a large evergreen tree of the Indian subcontinent and South-East Asia in the mahogany family, Meliaceae[1, 4]. The Ayurvedic Pharmacopoeia of India has five separate monographs for it (leaf, stem bark, root bark, flower and fruit) and names bitter triterpenoids and limonoids such as nimbin and nimbidiol as constituents[1, 2]. Human research is mostly small trials of mouthwashes, gels and toothpastes, plus a few trials of leaf and twig extract on blood sugar[9, 19, 20]. The main safety point is neem seed oil: swallowing it has been linked to serious poisoning, especially in young children[5, 6].

At a glance

Names and identity

Common nameNeem (margosa, Indian lilac, nimba)
SanskritNimba, Ariṣṭa, Picumarda
HindiNeem, Nim
PunjabiNim, Nimb
Botanical nameAzadirachta indica A.Juss. (syn. Melia azadirachta L., the name used in the API)
FamilyMeliaceae
Part usedLeaf, stem bark, root bark, flower and fruit (with seed) each have their own API monograph; the seed oil (neem or margosa oil) is a separate, higher-risk preparation. Not the same plant as Melia azedarach (Mahanimba, Persian lilac).
Sanskrit synonymsAriṣṭa, Picumarda, Picumanda, Prabhadra

Ayurveda

Neem in the Ayurvedic Pharmacopoeia

Rasa (taste)Tikta (bitter) in all five parts
Guna (qualities)Ruksha (dry) for the leaf; Laghu (light) and Ruksha for the stem bark; Laghu for root bark and flower; Laghu, Snigdha and Tikshna for the fruit
Virya (potency)Sheeta (cooling) for leaf, stem bark, root bark and flower; Ushna (heating) for the fruit
Vipaka (post-digestive effect)Katu (pungent)
Action on doshasKaphahara and Pittahara (stem bark, root bark, flower). Other actions listed include Kandughna, Vishaghna and Vranashodhana (stem bark), Chakshushya and Krimighna (flower), and Rasayana and Vatahara (fruit).
Karma (actions)Kaphahara, Pittahara, Kandughna, Vishaghna, Vranashodhana
Classical formulationsSudarshana Churna (stem bark), Nimbadi Kvatha Churna (stem bark), Panchatikta Guggulu Ghrita (stem bark), Arogyavardhini Gutika (leaf), Panchaguna Taila (leaf), Jatyadi Ghrita (leaf)
Dose in the APILeaf: 1-3 g of the drug in powder form, or 10-20 ml for decoction. Stem bark: 2-4 g of powder; the decoction is for external use. Root bark: 3-6 g. Flower: 2-4 g of flower powder or 10-20 ml of fresh flower juice. Fruit (with seed): 1-2 g of powder, or 5-10 drops of oil (API Part I, Vol II monographs 56 and 57; Vol V monographs 55-57).

Profile as recorded in the official texts[1, 2].

Chemistry

Key constituents

  • The API gives the constituents of neem leaf as triterpenoids and sterols, of the stem bark as the bitter principles nimbin and nimbiol, of the root bark as tetranortriterpenoids (including margocin, nimbidiol, nimbolicin and azadirinin), of the flower as 15-acetoxy-7-deacetoxydihydroazadirone (neeflone) and nonacosane, and of the fruit as a fixed oil with diterpenoids and triterpenoids (limonoids), including nimbin, gedunin, azadirachtin, nimbidinin and salanin[1, 2].
  • LiverTox describes neem (margosa) oil as a yellow oil with a disagreeable smell, about 20% free fatty acids and about 2% bitters (nimbin, nimbinin, nimbidin, nimbidol), with bitter concentrations varying between commercial samples[6].
  • Azadirachtin, the limonoid best known as a natural insect growth regulator, is the compound implicated in published neem oil poisoning reports, but the case reports we read do not show which component caused the harm[28, 5].
  • A 2022 review of neem's antimicrobial literature reports that most of the activity data come from laboratory studies of extracts and isolated compounds, and that clinical efficacy and in vivo safety still need to be established[25].
  • Trial results apply to the specific preparation used: a 2% mouthwash, a dental gel with 25 mg/g leaf extract, or a standardised aqueous leaf-and-twig extract do not predict what a plain leaf powder or a seed oil does[12, 15, 19].

Research

What human studies show

The bottom line

The best-supported human signal for neem is in oral hygiene, where small, mostly Indian trials of 2% mouthwash, gel and toothpaste report plaque and gingival scores similar to chlorhexidine, but the systematic reviews call the evidence limited and at risk of bias[9, 10]. Two Hyderabad trials of one standardised leaf extract report lower glucose and HbA1c, but come from one group and have not been repeated by others that we found[19, 20]. Most other claims, including antimicrobial, ulcer, contraceptive and anticancer activity, rest on laboratory, animal or very small studies, and none of the evidence supports using neem in place of medical care.

systematic reviewEvidence: limited

Plaque and gingivitis: neem mouthrinse (systematic review)

3 RCTs (206 records screened, searches to Feb 2015) comparing neem mouthrinse with chlorhexidine mouthrinse in people with gingivitis; no meta-analysis because of heterogeneity. Authors from AIIMS New Delhi and Davangere

The included trials reported that neem mouthrinse was as effective as chlorhexidine as an adjunct to toothbrushing for reducing plaque and gingival inflammation. The authors call the evidence lacking and in need of high-quality trials.[9]

Limitations: Only 3 trials; quality of reporting and methods were generally flawed with unclear risk of bias.

systematic reviewEvidence: limited

Dental plaque and gingivitis: plant extracts compared (systematic review)

47 trials of medicinal plant extracts as dental and periodontal antibiofilm agents (964 records screened); Azadirachta indica in 4 studies

Neem extracts showed efficacy similar to chlorhexidine for plaque and gingival scores in the four studies. The authors say more studies are needed to understand clinical relevance.[10]

Limitations: Neem results are a small part of a wider review, and the abstract gives no effect sizes for neem.

meta-analysisEvidence: limited

Plaque and gingivitis: miswak (pooled)

10 RCTs of miswak chewing sticks from Salvadora persica or Azadirachta indica, 9 pooled; GRADE assessment

Miswak was comparable with a toothbrush for plaque (SMD 0.39, 95% CI -0.05 to 0.83) and gingivitis scores, and as an adjunct to toothbrushing was more effective for plaque (SMD 0.68) and gingivitis (SMD 0.66).[11]

Limitations: Mixes two plant sources, so the result cannot be assigned to neem alone; included studies under-reported brushing method and frequency.

RCTEvidence: limited

Mouthwash vs chlorhexidine and tea (Indian trial)

n=30 healthy volunteers aged 18-25 at Jodhpur Dental College, 10 per group: 0.2% chlorhexidine, 2% neem or 0.5% tea mouthwash; up to 3 weeks; blinded

Plaque and gingival scores fell in all groups. Neem and tea showed gingival effects better than chlorhexidine (P < 0.05); the 0.5% tea mouthwash had the greatest anti-plaque effect, more than neem or chlorhexidine.[12]

Limitations: Only 10 people per arm; healthy young volunteers; the chlorhexidine arm stopped after week 2.

RCTEvidence: limited

Mouthwash vs chlorhexidine (Indian crossover trial)

n=40 participants aged 18-35, double-blind crossover, 2% neem mouthwash vs 0.2% chlorhexidine with a 1-week washout

Plaque fell slightly in both phases with no significant difference between mouthwashes; the gingival index fell in both groups. The authors conclude neem can be an alternative to chlorhexidine.[13]

Limitations: Small; the abstract gives short follow-up and does not separate a neem-specific effect from the group-wide change.

RCTEvidence: preliminary

Toothpaste (Indian trial)

n=30 first-year dental students, randomised double-blind, neem toothpaste vs control toothpaste

Plaque index and gingival index were significantly different between test and control groups after use. The authors suggest neem toothpaste as an adjunct for oral hygiene.[14]

Limitations: Small student sample; the abstract does not give the duration or effect sizes.

RCTEvidence: limited

Dental gel (Manipal, India)

Males aged 20-30, 6 weeks; mucoadhesive gel with neem leaf extract (25 mg/g) vs 0.2% chlorhexidine mouthwash as positive control

The gel significantly reduced plaque index and salivary bacterial count (P < 0.05) compared with the control group, as the authors report.[15]

Limitations: Males aged 20-30 only; sample size is not given in the abstract; the comparator was a chlorhexidine mouthwash used as a positive control, so the abstract does not describe a placebo.

otherEvidence: preliminary

Mutans streptococci and early caries (Manipal, India)

2-month study of neem mouthwash (with and without alcohol) against chlorhexidine; salivary S. mutans and lactobacilli counts

S. mutans was inhibited by neem mouthwashes and by chlorhexidine; lactobacilli were inhibited by chlorhexidine alone. The authors call their data initial and say longer clinical trials are essential.[16]

Limitations: 2001 study with sparse methods reported in the abstract; the claim of reversing incipient carious lesions rests on that early data.

RCTEvidence: preliminary

Five-herb mouthwash after periodontal therapy (Kerala, India)

Two RCTs (CTRI-registered): 50 people with periodontitis randomised to a mouthwash of five plant extracts (amla, haritaki, bibhitaki, mulethi and neem) or chlorhexidine for 2 weeks; a second study in radiation-induced mucositis versus soda saline

Bleeding, plaque and pocket depth fell significantly in both periodontitis groups. The herbal group reported less severe radiation mucositis and less analgesic need. Pain, dry mouth and antibiotic use did not differ significantly.[17]

Limitations: A five-plant formula, so no effect can be assigned to neem; preliminary trials.

RCTEvidence: limited

Root canal irrigant: pain and endotoxin (Cairo)

n=50 adults with necrotic lower molars, parallel double-blind; neem irrigant vs 2.5% sodium hypochlorite during endodontic therapy; pain at 6-48 h

Pain scores were lower with neem at every time point but significantly so only at 24 hours after instrumentation (P = 0.012). Both irrigants reduced endotoxin (18% neem, 8% hypochlorite); neither removed it completely.[18]

Limitations: Single centre, 50 patients; a procedure-specific irrigant, not an oral or topical consumer product.

RCTEvidence: moderate

Type 2 diabetes on metformin (Indian RCT)

n=80 people with type 2 diabetes already on metformin, Nizam's Institute of Medical Sciences, Hyderabad; standardised aqueous leaf-and-twig extract 125, 250 or 500 mg twice daily vs placebo, 12 weeks, double-blind

At all three doses the extract lowered post-meal and fasting glucose, HbA1c (for example 7.78% to 6.26% at 500 mg) and insulin resistance versus placebo, and improved endothelial function and inflammatory and oxidative markers. It did not change platelet aggregation or lipids.[19]

Limitations: One branded extract, 12 weeks, surrogate markers; reported by the same research group as the metabolic-syndrome trial, so the two are not independent confirmations.

RCTEvidence: limited

Metabolic syndrome (Indian RCT)

80 adults with metabolic syndrome, 20 per group; the same type of aqueous extract at 125, 250 or 500 mg twice daily vs placebo for 12 weeks; CTRI-registered

The extract dose-dependently improved fasting and post-meal glucose, insulin resistance, HbA1c, endothelial function and most inflammatory and oxidative markers over time.[20]

Limitations: Small groups; the abstract does not give effect sizes; surrogate markers; one research group.

RCTEvidence: preliminary

Prophylaxis in COVID-19 contacts (AIIA pilot, India)

n=190 healthcare workers or relatives of COVID-19 patients, single centre, double-blind placebo-controlled; 50 mg proprietary neem-leaf extract capsule twice daily for 28 days, follow-up to day 56

13 people tested positive (all asymptomatic). Among the 154 who completed per protocol, 3 in the neem group and 8 in the placebo group tested positive (relative risk 0.45). Adverse events were minimal and grade 1-2.[21]

Limitations: A pilot with very few events, so the estimate is imprecise; proprietary extract; outcome was a positive test in asymptomatic people; the authors call for further trials.

otherEvidence: preliminary

Gastric acid and duodenal ulcer (Kolkata, India)

Patients with acid-related problems and gastroduodenal ulcers took neem bark aqueous extract: 30 mg twice daily for 10 days (acid secretion) and 30-60 mg twice daily for up to 10 weeks (ulcers)

Gastric acid secretion fell by 77% after 10 days, and duodenal ulcers were reported as almost completely healed on barium meal or endoscopy at 10 weeks. Liver, kidney and blood markers stayed close to control values.[22, 5]

Limitations: The abstract describes no placebo or randomised comparison, and the group is small; MSK calls it 'a small study' and says more human studies are needed.

otherEvidence: preliminary

Head lice (Egypt)

60 heavily infested children aged 4-15 treated with a neem seed extract shampoo, left on for 5, 10, 15 or 30 minutes

The authors report that the shampoo was highly effective against all stages of head lice, with no differences between 10, 15 and 30 minutes and no skin irritation seen.[23]

Limitations: No comparison group described; an extract shampoo, not a plain preparation.

RCTEvidence: limited

Sand-flea infestation (tungiasis, Kenya)

n=96 children aged 6-14; topical 20% neem seed oil in coconut oil vs 0.05% potassium permanganate foot bath; fleas monitored for 6 days

Neem plus coconut oil killed about 40% of embedded fleas by day 6 and did not beat the potassium permanganate standard on that main outcome. Secondary outcomes (abnormal flea development, acute skin pathology, pain-free children) favoured the neem mixture.[24]

Limitations: Proof-of-principle trial with a short follow-up; topical seed oil on the skin of children, not an oral preparation.

Laboratory and animal studies

These studies explain possible mechanisms. They do not show the same effect in people.

in vitroEvidence: preliminary

Antimicrobial activity (review)

A 2022 narrative review of neem's antibacterial, antifungal, antiviral and antiparasitic literature, mainly laboratory and animal studies

The review describes activity against drug-resistant and biofilm-forming organisms in the laboratory, and concludes that mechanisms, clinical efficacy and in vivo safety still need study.[25]

Limitations: Not a systematic review; laboratory activity does not show a benefit in people.

animalEvidence: preliminary

Contraceptive activity (review)

PRISMA-guided review of 27 studies (1980-2020) on antifertility, antispermatogenic, anti-ovulation and abortifacient effects of A. indica, mostly in animals

The authors conclude that extracts and compounds showed a temporary, reversible contraceptive effect in animal models, and that clinical studies are lacking.[26]

Limitations: Almost entirely animal data; no human contraceptive efficacy is shown.

Safety

Safety, interactions and regulation

  • Neem seed oil by mouth: LiverTox and MSK both describe serious poisoning after ingestion of neem (margosa) oil, with vomiting, drowsiness, seizures, severe metabolic acidosis and coma, a pattern similar to Reye syndrome; liver enzymes may be normal at first and rise later. Cases are reported from India and Malaysia, and LiverTox rates it a probable rare cause of clinically apparent liver injury (likelihood score C). MSK warns that swallowing neem oil has caused severe poisoning in both children and adults[5, 6].
  • Case reports we read: a previously healthy 5-year-old with refractory seizures and metabolic acidosis who later had hearing, vision and balance problems[27]; an elderly man with vomiting, seizures, metabolic acidosis and toxic encephalopathy who recovered with supportive care[28]; and a 35-year-old woman who drank about 150 ml and lost vision in both eyes, with partial recovery to 20/200 after two months[29]. These are individual reports, not rates.
  • Why the oil is harmful is not settled. LiverTox notes that neem oil has been used for centuries in Ayurveda and says the outbreaks may reflect contamination of otherwise tolerated oil by seeds of lookalike plants; it also notes that A. indica DNA has been found as a contaminant in commercial herbal supplements in at least one screening report. Its proposed mechanism is mitochondrial dysfunction from a component or contaminant[6].
  • Leaf, bark and twig extracts: in the trials above, adverse events were minimal (grade 1-2 in the COVID prophylaxis pilot[21]), and organ-toxicity markers stayed near control values in the bark-extract ulcer study[22]. These trials are short (10 days to 12 weeks) and small, so they cannot rule out rare reactions, and LiverTox has no chapter for neem leaf or bark.
  • Skin: MSK lists allergic contact dermatitis from topical neem oil, including a scalp and face reaction after use for hair loss and a bullous pemphigoid flare in a woman using it on blisters[5]. A 2017 report notes that contact allergy to neem oil had been described in only 3 patients before and that the allergen is unknown[30].
  • Regulators: in Australia a 2003 TGA committee record describes the scheduling decision then in force, which did not allow neem or its extracts in preparations for human internal use in listed medicines, allowed dermal use up to 1% without special labelling, and above 1% required a child-resistant container and the statements 'Not to be taken', 'Keep out of the reach of children' and 'Do not use if pregnant or likely to become pregnant'. The pregnancy warning reflected the absence of proper dermal absorption studies, not a demonstrated harm[7]. Health Canada, by contrast, has an active licence for an oral neem tablet for adults aged 19 and over[8]. We did not verify current Australian rules.
  • Pregnancy, breastfeeding and fertility: we found no human safety data for oral neem leaf or bark in pregnancy or breastfeeding. A 2021 review of mostly animal studies reports temporary, reversible contraceptive effects of neem, with no clinical studies, so use when trying to conceive or in pregnancy should be discussed with a doctor[26, 7].
  • Blood sugar and medicines: the Hyderabad trials recorded lower glucose and HbA1c on top of metformin, so people on diabetes medicines should ask their doctor before using neem extracts[19, 20]. MSK notes that a neem extract inhibited CYP3A4/5, 2C8 and 2C9 enzymes in vitro and that clinical relevance is unknown[5].
  • Gaps: no EMA/HMPC monograph, NCCIH page or India-specific regulatory action on neem was found; no controlled safety data exist for long-term daily use of leaf powder. These are limits of our search, not statements that none exist.

Quality

Identity, standards and adulteration

  • API identity: the leaf is compound with serrate, lanceolate leaflets and a bitter taste, with anomocytic stomata on the lower surface and rosette crystals of calcium oxalate. The stem bark is rough, fissured, rusty-grey outside with a fibrous fracture, reddish-brown powder, prismatic calcium oxalate crystals, stone cells and simple starch grains[1].
  • API limits, leaf: foreign matter not more than 2%; total ash not more than 10%; acid-insoluble ash not more than 1%; alcohol-soluble extractive not less than 13%; water-soluble extractive not less than 19%. Stem bark: total ash not more than 7%, acid-insoluble ash not more than 1.5%, alcohol-soluble extractive not less than 6%, water-soluble extractive not less than 5%[1].
  • API limits, other parts: root bark total ash not more than 15%, acid-insoluble ash not more than 3%, extractives not less than 6% (alcohol) and 7% (water); flower total ash not more than 14%, acid-insoluble ash not more than 5%, extractives not less than 5% and 12%; fruit total ash not more than 8%, acid-insoluble ash not more than 2%, extractives not less than 16% and 19%. Foreign matter is not more than 2% for each[2].
  • Species identity: the API lists Mahanimba (Melia azedarach Linn., Persian lilac) as a separate drug from Nimba[3]. POWO lists Melia azadirachta L. as a synonym of Azadirachta indica, whereas Melia azedarach is a different species[4]. A specification should state the binomial and the part used, and the oil should be identified as seed oil from Azadirachta indica.
  • Standardisation: the trials used a standardised aqueous leaf-and-twig extract (125-500 mg twice daily) and a proprietary leaf extract (50 mg twice daily), and the API sets no assay marker for azadirachtin or nimbin in any monograph; manufacturers wanting to match trial material need to specify extract type and markers[19, 21, 1, 2].
  • Adulteration and contaminants: LiverTox mentions possible contamination of margosa oil with seeds of lookalike plants and A. indica DNA as a contaminant in commercial herbal supplements[6], but we did not find a peer-reviewed survey of neem leaf or bark adulteration or heavy metals that we could open and verify. This is a gap.

Manufacturing

How Neem is made into medicines

In Ayurvedic practice neem is used as leaf powder or decoction, stem bark powder and decoction, flower powder and juice, and as a component of formulations such as Sudarshana Churna, Nimbadi Kvatha Churna, Panchatikta Guggulu Ghrita, Arogyavardhini Gutika and Panchaguna Taila[1, 2]. The API gives leaf 1-3 g and stem bark 2-4 g as powder doses[1]. Modern products include aqueous leaf extracts in capsules (trial doses of 50-500 mg twice daily), mouthwashes, dental gels and toothpastes[12, 15, 19, 21]. Seed oil (fixed oil) is a separate material with a different safety profile; the API fruit monograph lists '5-10 drops of oil' as a dose, and the route is not stated in the text we read[2, 6]. For manufacturers, raw material should be authenticated against the API identity tests and ash and extractive limits for the specific part, kept separate from Melia azedarach, and the seed oil should be handled as an external or tightly controlled material, with child-resistant packaging and clear labelling if offered[1, 2, 3, 7].

Prabhat makes churnas, tablets, capsules, kwaths, syrups and oils under AYUSH GMP for brands across India. See churna, tablet and capsule manufacturing, or white label products.

FAQ

Common questions about Neem

What is neem good for?

Neem is a traditional Ayurvedic bitter used for skin conditions, fever and worms; the API lists Kushtha, Kandu, Krimiroga, Prameha and Vrana among the traditional uses of the leaf and stem bark[1]. In modern research it has been studied most in mouthwashes and dental gels, and in a few trials of leaf extract on blood sugar[9, 19, 20]. It is not shown to prevent or manage any disease.

Is neem safe to take every day?

Short trials of leaf-and-twig extract for up to 12 weeks reported minimal adverse events[19, 20, 21], but there are no long-term safety studies of daily leaf powder. Neem seed oil should not be swallowed: it has been linked to serious poisoning[5, 6]. People on diabetes medicines should ask their doctor first[19].

Can neem oil be taken by mouth?

LiverTox and MSK both warn against it. They describe severe poisoning, with seizures, metabolic acidosis and liver involvement, after ingestion of neem oil, particularly in young children[5, 6]. Case reports describe adult poisoning too[28, 29].

Is neem mouthwash as good as chlorhexidine?

Small trials found neem mouthwash scores comparable to chlorhexidine, but a systematic review of the 3 earliest trials called the evidence lacking and the methods flawed[9, 12, 13]. A wider review reported similar plaque and gingival scores to chlorhexidine in four neem studies and said more research is needed[10].

Does neem lower blood sugar?

Two Hyderabad trials of a standardised aqueous leaf-and-twig extract reported lower glucose, HbA1c and insulin resistance than placebo over 12 weeks, including in people on metformin[19, 20]. Both come from one research group and are small, so the finding needs confirming by others, and it does not apply to plain leaf powder.

Is neem safe in pregnancy?

We found no human safety studies of oral neem in pregnancy. Neem extracts showed temporary contraceptive effects in animal studies, and Australia's 2003 scheduling decision required a 'Do not use if pregnant' label on stronger topical products[26, 7]. Ask a doctor before using neem products when pregnant or trying to conceive.

References

Sources

  1. Government of India, Ministry of Health and Family Welfare, Department of AYUSH. The Ayurvedic Pharmacopoeia of India, Part I, Volume II. Monograph No. 56 (Nimba, leaf) and No. 57 (Nimba, stem bark), Azadirachta indica A. Juss. Source.
  2. Government of India, Ministry of Health and Family Welfare, Department of AYUSH. The Ayurvedic Pharmacopoeia of India, Part I, Volume V. Monograph No. 55 (Nimba, root bark), No. 56 (Nimba, flower) and No. 57 (Nimba, fruit), Azadirachta indica A. Juss. Source.
  3. Government of India, Ministry of Health and Family Welfare, Department of AYUSH. The Ayurvedic Pharmacopoeia of India, Part I, Volume IV. Monograph No. 28 (Mahanimba, stem bark), Melia azedarach Linn. Source.
  4. Plants of the World Online (POWO). Azadirachta indica A.Juss. Royal Botanic Gardens, Kew. Accessed 12 Nov 2026. Source.
  5. Memorial Sloan Kettering Cancer Center. About Herbs: Neem (Purported benefits, side effects and more). Last updated 23 May 2025. Source.
  6. National Institute of Diabetes and Digestive and Kidney Diseases. Margosa Oil. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Updated 5 February 2020. Source.
  7. Therapeutic Goods Administration (Australia), Complementary Medicines Evaluation Committee. Extracted Ratified Minutes, Thirty Ninth Meeting, 11 April 2003 (item 5.1, Neem, Azadirachta indica; recommendations 39.2 and 39.3). Source.
  8. Health Canada, Licensed Natural Health Products Database. Product information, NPN 80095023 (Organic Neem / Neem tablet, Himalaya Wellness USA Ltd.). Licensed 25 Oct 2019, revised 3 Dec 2024. Source.
  9. Dhingra K, Vandana KL. Effectiveness of Azadirachta indica (neem) mouthrinse in plaque and gingivitis control: a systematic review. Int J Dent Hyg. 2017;15(1):4-15. PMID: 26876277. doi: 10.1111/idh.12191.
  10. Furquim Dos Santos Cardoso V, Amaral Roppa RH, Antunes C, Silva Moraes AN, Santi L, Konrath EL. Efficacy of medicinal plant extracts as dental and periodontal antibiofilm agents: A systematic review of randomized clinical trials. J Ethnopharmacol. 2021;281:114541. PMID: 34416298. doi: 10.1016/j.jep.2021.114541.
  11. Ramli H, Nor Aripin KN, Mohd Said S, Mohamad Hanafiah R, Mohd Dom TN. The effectiveness of miswak (Salvadora persica L. and Azadirachta indica A.Juss.) practices in reducing plaque and gingivitis among adults: A systematic review and meta-analysis. J Ethnopharmacol. 2022;298:115598. PMID: 35944735. doi: 10.1016/j.jep.2022.115598.
  12. Balappanavar AY, Sardana V, Singh M. Comparison of the effectiveness of 0.5% tea, 2% neem and 0.2% chlorhexidine mouthwashes on oral health: a randomized control trial. Indian J Dent Res. 2013;24(1):26-34. PMID: 23852229. doi: 10.4103/0970-9290.114933.
  13. Jalaluddin M, Rajasekaran UB, Paul S, Dhanya RS, Sudeep CB, Adarsh VJ. Comparative Evaluation of Neem Mouthwash on Plaque and Gingivitis: A Double-blind Crossover Study. J Contemp Dent Pract. 2017;18(7):567-571. PMID: 28713109. doi: 10.5005/jp-journals-10024-2085.
  14. Abhishek KN, Supreetha S, Sam G, Khan SN, Chaithanya KH, Abdul N. Effect of Neem containing Toothpaste on Plaque and Gingivitis--A Randomized Double Blind Clinical Trial. J Contemp Dent Pract. 2015;16(11):880-3. PMID: 26718296. doi: 10.5005/jp-journals-10024-1776.
  15. Pai MR, Acharya LD, Udupa N. Evaluation of antiplaque activity of Azadirachta indica leaf extract gel--a 6-week clinical study. J Ethnopharmacol. 2004;90(1):99-103. PMID: 14698516. doi: 10.1016/j.jep.2003.09.035.
  16. Vanka A, Tandon S, Rao SR, Udupa N, Ramkumar P. The effect of indigenous Neem Azadirachta indica [correction of (Adirachta indica)] mouth wash on Streptococcus mutans and lactobacilli growth. Indian J Dent Res. 2001;12(3):133-44. PMID: 11808064.
  17. Ambili R, Ramadas K, Nair LM, Raj D, Nazeer F, George PS, et al. Efficacy of a herbal mouthwash for management of periodontitis and radiation-induced mucositis - A consolidated report of two randomized controlled clinical trials. J Ayurveda Integr Med. 2023;14(6):100791. PMID: 37897968. doi: 10.1016/j.jaim.2023.100791.
  18. Hosny NS, El Khodary SA, El Boghdadi RM, Shaker OG. Effect of Neem (Azadirachta indica) versus 2.5% sodium hypochlorite as root canal irrigants on the intensity of post-operative pain and the amount of endotoxins in mandibular molars with necrotic pulps: a randomized controlled trial. Int Endod J. 2021;54(9):1434-1447. PMID: 33884661. doi: 10.1111/iej.13532.
  19. 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. doi: 10.2147/DMSO.S274378.
  20. Pingali U, Vuppalanchi B, Nutalapati C, Gundagani S. Aqueous Azadirachta indica (Neem) Extract Attenuates Insulin Resistance to Improve Glycemic Control and Endothelial Function in Subjects with Metabolic Syndrome. J Med Food. 2021;24(11):1135-1144. PMID: 34582720. doi: 10.1089/jmf.2020.4838.
  21. Nesari TM, Bhardwaj A, ShriKrishna R, Ruknuddin G, Ghildiyal S, Das A, et al. Neem (Azadirachta Indica A. Juss) Capsules for Prophylaxis of COVID-19 Infection: A Pilot, Double-Blind, Randomized Controlled Trial. Altern Ther Health Med. 2021;27(S1):196-203. PMID: 33891569.
  22. Bandyopadhyay U, Biswas K, Sengupta A, Moitra P, Dutta P, Sarkar D, et al. Clinical studies on the effect of Neem (Azadirachta indica) bark extract on gastric secretion and gastroduodenal ulcer. Life Sci. 2004;75(24):2867-78. PMID: 15454339. doi: 10.1016/j.lfs.2004.04.050.
  23. Abdel-Ghaffar F, Semmler M. Efficacy of neem seed extract shampoo on head lice of naturally infected humans in Egypt. Parasitol Res. 2007;100(2):329-32. PMID: 16900389. doi: 10.1007/s00436-006-0264-2.
  24. Elson L, Randu K, Feldmeier H, Fillinger U. Efficacy of a mixture of neem seed oil (Azadirachta indica) and coconut oil (Cocos nucifera) for topical treatment of tungiasis. A randomized controlled, proof-of-principle study. PLoS Negl Trop Dis. 2019;13(11):e0007822. PMID: 31756189. doi: 10.1371/journal.pntd.0007822.
  25. Wylie MR, Merrell DS. The Antimicrobial Potential of the Neem Tree Azadirachta indica. Front Pharmacol. 2022;13:891535. PMID: 35712721. doi: 10.3389/fphar.2022.891535.
  26. Patil SM, Shirahatti PS, V B CK, Ramu R, M N NP. Azadirachta indica A. Juss (neem) as a contraceptive: An evidence-based review on its pharmacological efficiency. Phytomedicine. 2021;88:153596. PMID: 34092456. doi: 10.1016/j.phymed.2021.153596.
  27. Dhongade RK, Kavade SG, Damle RS. Neem oil poisoning. Indian Pediatr. 2008;45(1):56-7. PMID: 18250509.
  28. Mishra A, Dave N. Neem oil poisoning: Case report of an adult with toxic encephalopathy. Indian J Crit Care Med. 2013;17(5):321-2. PMID: 24339648. doi: 10.4103/0972-5229.120330.
  29. Suresha AR, Rajesh P, Anil Raj KS, Torgal R. A rare case of toxic optic neuropathy secondary to consumption of neem oil. Indian J Ophthalmol. 2014;62(3):337-9. PMID: 24722271. doi: 10.4103/0301-4738.121129.
  30. de Groot A, Jagtman BA, Woutersen M. Contact Allergy to Neem Oil. Dermatitis. 2017;28(6):360-362. PMID: 29059091. doi: 10.1097/DER.0000000000000309.

How this page was written. Every statement links to a source we opened. PubMed IDs were checked against the NCBI database. Human studies are kept apart from laboratory and animal work, and null results are included. Read our method.

Author: Aashish Passi, Managing Director, Prabhat Ayurvedic Pharmacy. Last updated: 12 November 2026. Spotted an error? Email info@prabhatayurvedicpharmacy.in.

This page is educational and summarises published research. It is not medical advice and is not a claim for any product. Talk to a qualified doctor before using any herbal medicine, especially if you are pregnant, breastfeeding, taking medicines or have a medical condition.

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