Purulent (pustular) acne is the inflammatory end of acne vulgaris. It involves blocked pilosebaceous follicles, Cutibacterium acnes overgrowth and a strong inflammatory response. Acne pathogenesis combines inflammation, abnormal shedding of follicular epithelium and follicular colonisation by C. acnes. Ayurvedic practice treats such lesions (mukhadushika) with lepa, a topical paste. Neem (Azadirachta indica) and haridra (Curcuma longa) are the classical pairing.
Neem: Antimicrobial and multitarget activity
Neem leaf and oil contain azadirachtin, nimbidin and nimbolide. Neem extracts inhibit C. acnes and other skin pathogens such as Staphylococcus aureus. A 2023 study in Molecules analysed neem oil by GC-MS and network pharmacology. It identified 39 compounds in the oil and 17 genes shared between neem oil targets and acne targets.1 This supports a multitarget anti-inflammatory mechanism, though it is computational and not clinical evidence.
Haridra: Curcumin as an anti-inflammatory agent
Curcumin is the principal bioactive polyphenol of turmeric. It has anti-inflammatory, antimicrobial, antioxidant and wound-healing properties, and experimental and clinical data suggest a role as an adjunct in acne. A recent study tested alcoholic turmeric extract on S. aureus, C. acnes and S. epidermidis. All three strains were inhibited, and the inhibition zone widened as extract concentration rose. This dose-response pattern matters for pustular lesions, where staphylococcal co-colonisation is common.2
Clinical evidence for the combination
The best-documented trial involved a neem-and-turmeric face wash. It was a four-week, open-label, single-arm study in people with mild-to-moderate acne or oily skin, and it reported reduced acne with no side effects. The study has clear limits: it was uncontrolled, short, and tested a wash rather than a leave-on lepa. No randomised trial of a classical neem-haridra lepa for purulent acne was found. Reviews note that neem formulations and study designs vary widely, and that standardised clinical trials are still needed.
Local applications (bahirparimarjana chikitsā) like lepas are prescribed based on the dominant doṣa. Nimba Taila is often used externally to manage inflammation, itching, and bacterial infections.3
Moreover, Nimbādi Guggulu is a tablet formulation containing Nimba, Guggulu, Haridra, and Triphala. It is specifically indicated in Kapha-Pitta Kushtha, acne, infected eczema, and pustular eruptions.
Practical Lepa protocol (Traditional practice)
The following is a commonly described protocol, not a trial-validated regimen:
- Preparation: Grind fresh neem leaves (or use neem leaf powder) with turmeric powder. Mix with rose water or plain water to a smooth paste. Use a fresh batch each time.
- Application: Cleanse the face and apply a thin layer to affected areas only. Avoid the eye margins.
- Duration: Leave on for 15–20 minutes and rinse before it dries completely, to limit irritation.
- Frequency: Once daily or on alternate days for 2–4 weeks, then reassess.
- Adjuncts: Avoid squeezing pustules, use a gentle cleanser and non-comedogenic moisturiser, and do a patch test first.
Safety and Limitations
Turmeric stains the skin yellow temporarily and can cause contact dermatitis in sensitised people. Neem oil can also irritate. Homemade pastes vary in potency and may carry microbial contamination if prepared carelessly. Nodulocystic, scarring or widespread purulent acne, or acne with systemic symptoms, needs dermatological care. Standard options include topical retinoids, benzoyl peroxide and antibiotics, and a lepa should not replace these.
Conclusion
Laboratory, mechanistic and small clinical data support the antimicrobial and anti-inflammatory rationale for neem-haridra lepa in pustular acne. Large, controlled trials with standardised extracts and defined lepa protocols are the main gap. Until then, it is best positioned as a complementary measure for mild-to-moderate lesions.
References:
- Gopinath H, Karthikeyan K. Neem in Dermatology: Shedding Light on the Traditional Panacea. Indian J Dermatol. 2021;66(6):706. doi:10.4103/ijd.ijd_562_21. https://pmc.ncbi.nlm.nih.gov/articles/PMC8906293/
- Teow SY, Liew K, Ali SA, Khoo AS, Peh SC. Antibacterial Action of Curcumin against Staphylococcus aureus: A Brief Review. J Trop Med. 2016;2016:2853045. doi:10.1155/2016/2853045. https://pmc.ncbi.nlm.nih.gov/articles/PMC5124450/
- Koirala P, Gautam M. Role of Ayurvedic Herbal Formulations and Naturopathic Therapies in Managing Skin Disorders. Journal of Ayurveda and Naturopathy. 2025;2(1):38-42. https://www.ayurvedjournal.net/archives/2025/vol2issue1/PartA/2-1-7-339.pdf