Neem

Names and identification

Language	Name
English	Neem
Common Names	Neem, Indian Lilac, Margosa
Hindi	Neem, Nimba
Sanskrit	Nimba, Arishta
Latin/Botanical	Azadirachta indica

Parts Used

• Leaf
• Bark
• Seed
• Oil
• Flower
• Root

Dosha Effects

Dosha	Effect
Pitta	Decreases
Kapha	Decreases
Vata	May Increase

Key Phytochemical Constituents

• Azadirachtin
• Nimbin
• Nimbidin
• Nimbidol
• Gedunin
• Quercetin

Therapeutic Actions (Karma)

• Antibacterial
• Antifungal
• Anti-parasitic
• Blood purifier
• Anti-diabetic
• Antipyretic
• Insecticidal

How does it work?

• Azadirachtin blocks TNF-induced NF-kB activation by binding to TNFR1 at the TNF binding site, preventing TNF binding and downstream signaling
• Inhibits IkBalpha phosphorylation and degradation, blocking RelA (p65) nuclear translocation
• Reduces pro-inflammatory cytokines TNF-alpha, IL-6, IL-1beta, TLR4, and NF-kB in dose-dependent manner
• Nimbolide and azadirachtin show concentration-dependent free radical scavenging and reductive potential
• Prevents procarcinogen activation and oxidative DNA damage; upregulates antioxidant and carcinogen detoxification enzymes
• Synergistic activity with existing antibiotics against multidrug-resistant bacterial species
• Gedunin acts as HSP90 inhibitor, disrupting protein folding in cancer cells

How is it used traditionally?

Called ‘Sarva Roga Nivarini’ (curer of all ailments). Extensively used in Kushtha (skin diseases), Prameha (diabetes), and Krimi (parasitic infections). Twigs used as toothbrush (Datun).

Where is it described in the classical texts?

• Charaka Samhita
• Sushruta Samhita
• Bhavaprakasha Nighantu

What do recent clinical trials show?

• Tufail T, Bader Ul Ain H, Ijaz A and others 2025. Neem (Azadirachta indica): A Miracle Herb; Panacea for All Ailments. Food science & nutrition. PMID 40901661 · doi:10.1002/fsn3.70820
  Comprehensive review covering neem’s applications across pharmaceuticals, agriculture, cosmetics, and fuel production, with focus on broad-spectrum antimicrobial, anticancer, and anti-diabetic properties.
• Anuradha DS, Jaganathan B 2025. Predictive modelling and ranking: Azadirachta indica compounds through indices and multi-criteria decision-making techniques. Frontiers in chemistry. PMID 40365176 · doi:10.3389/fchem.2025.1580267
  Computational study using molecular descriptor indices to rank neem bioactive compounds for drug discovery prioritization, identifying azadirachtin, nimbin, and gedunin as top candidates.
• Wylie MR, Merrell DS 2022. The Antimicrobial Potential of the Neem Tree Azadirachta indica. Frontiers in pharmacology. PMID 35712721 · doi:10.3389/fphar.2022.891535
  Comprehensive review of antimicrobial activities across dentistry, food safety, bacteriology, mycology, virology, and parasitology. Nimbins demonstrated activity against four dengue virus strains.

3 further claims previously listed here could not be traced to a published paper and have been removed. An absence here means we could not identify the source, not that no work exists.

Recent safety updates

• Non-aqueous extracts are most toxic neem products (ESD: 0.002-12.5 mcg/kg bw/day); aqueous extracts safer (ESD: 0.3 mg/kg bw/day)
• Prolonged use may cause renal dysfunction, decreased arterial blood pressure, and hypoglycemic responses
• Reversible anti-fertility effects on both male and female mammals documented upon sub-acute or chronic exposure
• Drug interaction (MODERATE): potentiates hypoglycemic agents - may cause dangerously low blood sugar
• Drug interaction (MODERATE): may alter lithium levels requiring dose adjustment
• Drug interaction (MODERATE): may interfere with immunosuppressant medications - contraindicated for organ transplant recipients
• Insufficient long-term safety data in humans - need for more funded toxicology research emphasized in 2025 bibliometric analysis
• Neem oil ingestion in children has been associated with serious adverse events including toxic encephalopathy

Recommended Dosage

Leaf powder: 2-4g/day; Leaf juice: 10-20ml/day; Neem oil: external use only

Safety, contraindications and cautions

• Pregnancy (abortifacient)
• Trying to conceive (anti-fertility)
• Infants/children (internal use)
• Organ transplant patients (immunostimulant)

What is it made of?

Part(s) Analyzed: Leaf/Bark/Seed

Terpenoids

• Azadirachtin (0.2-0.6%)
• Nimbin (0.1-0.3%)
• Nimbidin
• Nimbinin
• Nimbolide (0.05-0.2%)
• Salannin
• Gedunin
• Mahmoodin

Flavonoids

• Quercetin (0.1-0.3%)
• Kaempferol
• Myricetin
• Rutin

Alkaloids

• Nimbimine
• Nimbidine
• Nimbinine

Phenolics

• Gallic acid (0.5-1.0%)
• Catechol
• Protocatechuic acid

Tannins

• Condensed tannins (2-5%)
• Gallic acid tannins

Steroids_Saponins

• Beta-sitosterol (0.1%)
• Stigmasterol
• Campesterol

Glycosides

• Nimbosterol
• Nimbioside

Fatty_acids

• Oleic acid (40-50%)
• Stearic acid (15-20%)
• Palmitic acid (15-18%)

Coumarins

• Scopoletin (trace)
• Margosine

Essential Oil Composition

• Azadirachtin: 0.2-0.6%
• Nimbin: 0.1-0.3%
• Limonoids: major fraction

Analytical Methods: HPLC, LC-MS, GC-MS, HPTLC, UV-Vis spectrophotometry

Dosage forms and preparation

Dosage Forms: Tablet, Capsule, Churna (powder), Kwatha (decoction), Oil (external), Cream/ointment, Arishtam, Soft gel capsule, Tincture

Standard Dosage: 1-3 g dried leaf powder per day; 400-800 mg standardized extract per day; 10-20 mL leaf decoction twice daily; topical oil as needed

Bioavailability: Azadirachtin and nimbidin show moderate oral bioavailability (25-40%) due to hepatic first-pass metabolism and poor aqueous solubility. Limonoids are lipophilic and benefit from lipid-based delivery systems (SEDDS, nanoemulsions) which can boost bioavailability 2-3 fold. Gallic acid and quercetin present in leaf have reasonable absorption (~30-45%).

Optimal Timing: Oral supplements best taken after meals to reduce GI irritation. Topical applications as needed, preferably evening application for dermatological conditions.

Standardized Extract: Standardized neem leaf extract (10:1) containing minimum 2.5% bitter principles (as nimbidin), minimum 0.3% azadirachtin. Neem seed extract standardized to 5% azadirachtin for agricultural applications. Neem bark extract standardized to nimbin >1.5%.

Shelf Life: Dried leaf powder: 18-24 months; Standardized extract: 24-36 months; Neem oil: 12-18 months; Tablets/Capsules: 24-36 months

Storage: Store in airtight containers below 25 deg C, protected from light and moisture. Neem oil requires amber glass or HDPE containers, storage below 30 deg C. Azadirachtin-rich extracts require refrigerated storage (2-8 deg C) for long-term stability.

Marker Compounds: Azadirachtin, Nimbidin, Nimbin, Nimbolide, Gedunin, Gallic acid, Quercetin, Salannin, Epinimbin

Extraction Methods

• Hydroalcoholic extraction (50-70% ethanol)
• Cold-pressed seed oil extraction
• Supercritical CO2 extraction for azadirachtin-rich fractions
• Aqueous decoction (traditional Kwatha)
• Soxhlet extraction with ethanol for standardized extract production
• Steam distillation for neem oil volatile fraction

Synergistic Combinations

• Haridra/Turmeric (enhanced anti-inflammatory and wound healing)
• Tulsi (synergistic antimicrobial action)
• Karanja (potentiated insecticidal and dermatological effects)
• Guduchi (hepatoprotection with immune modulation)
• Manjistha (blood purification and skin health)