Andrographis paniculata (Burm. f.) Wall. ex Nees, commonly called Kalmegh or Kālamegha, is an Acanthaceae herb used in Ayurveda. Its strongest human evidence concerns short-term relief of symptoms in uncomplicated acute respiratory tract infections, not confirmed elimination of respiratory viruses. It is therefore more accurate to describe Kalmegha as an Ayurvedic drug with product-specific respiratory symptom evidence than as a proven broad-spectrum antiviral.

Botanical and Ayurvedic Identity

The Ayurvedic Pharmacopoeia of India, Part I, Volume VIII, identifies Kālamegha as the aerial part of Andrographis paniculata and provides a separate monograph for its powder. Kalmegha is not the same botanical drug as Kirātatikta: an official Indian medicinal-plant profile identifies the former as A. paniculata and the latter as Swertia chirata, although both have sometimes been called Bhūnimba.

Common Dravyaguna descriptions assign Kalmegha Tikta rasa; Laghu, Ruksha and Tikshna guna; Ushna virya; Katu vipaka; and Kapha-Pitta-shamana action. Traditional indications include Jvara, Agnimandya and Yakrit disorders. These Ayurvedic categories should not be translated directly into claims that the herb kills viruses or boosts a specific immune pathway.

Phytochemical Identity and Standardization

Andrographolide is the principal analytical marker, but Kalmegha contains a mixture of diterpenoids. Frequently reported constituents include neoandrographolide, 14-deoxyandrographolide, andrograpanin and 14-deoxy-11,12-didehydroandrographolide. Their proportions vary with plant material, harvest and extraction, so crude powder, aqueous extract, hydroalcoholic extract and isolated andrographolide are not dose-equivalent. Results from one named extract or fixed combination cannot automatically be applied to every Kalmegha product.

Antiviral and Anti-inflammatory Mechanisms

Laboratory research supports biological plausibility but remains preclinical. Andrographolide has been shown to form a covalent adduct with reduced cysteine 62 of the NF-κB p50 subunit, thereby inhibiting NF-κB DNA binding. This demonstrates an anti-inflammatory molecular action; it does not prove that oral Kalmegha prevents a cytokine storm or improves severe viral disease.

An in vitro study found that an A. paniculata extract and andrographolide inhibited production of infectious SARS-CoV-2 particles in infected Calu-3 lung cells. Cell-culture activity does not establish an effective human dose, adequate tissue exposure or clinical benefit for COVID-19, influenza, herpes or other viral infections. Human evidence does not establish interferon boosting, viral-entry blockade or clinically effective viral-protease inhibition.

Clinical Evidence for Respiratory Infections

A 2017 systematic review and meta-analysis included 33 randomized controlled trials involving 7,175 participants with acute respiratory tract infections. Compared with placebo, Andrographis preparations improved cough scores in 596 participants (standardized mean difference −0.39; 95% confidence interval −0.67 to −0.10) and sore-throat scores in 314 participants (standardized mean difference −1.13; 95% confidence interval −1.37 to −0.89). The authors emphasized poor overall methodological quality, heterogeneous products and inconsistent outcome reporting.

An earlier review by Coon and Ernst, PMID 15095142, found that A. paniculata appeared superior to placebo for subjective symptoms of uncomplicated upper respiratory infection, while calling for more research. These studies evaluated symptoms; they did not establish viral clearance, prevention of pneumonia or replacement of necessary antibiotics.

In PMID 10589439, 158 adults received SHA-10 dried extract at 1,200 mg/day or placebo for five days, with improvement reported in selected cold symptoms. In PMID 20092985, 223 participants received KalmCold 200 mg/day or placebo, with most between-group symptom differences reported at day five. A 152-patient pharyngotonsillitis trial, PMID 1797953, found that paracetamol and 6 g/day of crude A. paniculata performed better than the lower herbal dose for fever and sore throat at day three; effects did not differ at day seven. It was not a formal non-inferiority trial and did not establish superior tolerability.

Clinical Trials Summary

The table lists verified study details. These regimens describe particular research products and are not universal self-treatment doses.

Evidence Reference Design Regimen Interpretation
Acute respiratory infections PMID 28783743 33 RCTs; 7,175 participants Multiple preparations Possible symptom benefit; poor quality and heterogeneity limit certainty.
Common-cold symptoms PMID 10589439 Placebo-controlled; 158 adults SHA-10, 1,200 mg/day for 5 days Selected symptoms improved with the studied extract.
Uncomplicated URTI PMID 20092985 Placebo-controlled; 223 participants KalmCold, 200 mg/day Most assessed symptoms favored the extract at day 5.
Pharyngotonsillitis PMID 1797953 Comparative trial; 152 patients Two crude-herb doses versus paracetamol The 6 g/day group and paracetamol outperformed the lower dose at day 3.

Evidence Map

The central distinction is between pharmacopoeial identity, laboratory activity and clinically measured symptom relief. These levels should not be merged into a claim of proven antiviral treatment.

KALMEGHA: LEVELS OF EVIDENCE
IDENTITY
API aerial part of A. paniculata.
LABORATORY
NF-κB and antiviral cell-culture findings.
CLINICAL
Changes in cough, sore throat and symptom scores.
NOT PROVEN
Viral clearance or prevention of complications.

Safety and Drug Interactions

Clinical reviews mainly report gastrointestinal complaints, headache, rash or other skin reactions, but severe allergy is an important risk. Australia’s Therapeutic Goods Administration warns that Andrographis medicines can cause sudden, unpredictable and potentially life-threatening anaphylaxis, including after previous uneventful use. Stop the product and seek urgent care for breathing difficulty, tongue or throat swelling, wheezing, persistent dizziness or collapse.

People who are pregnant or breastfeeding, take prescription medicines or have significant chronic illness should consult a qualified Ayurvedic practitioner and healthcare provider before use.

Dosage and Responsible Use

There is no single evidence-based dose for every Kalmegha product. Trials used markedly different preparations, including 1,200 mg/day of SHA-10, 200 mg/day of KalmCold and 6 g/day of crude herb. Extract ratios and andrographolide content differ, so these milligram or gram amounts cannot be transferred safely between products.

In Ayurvedic practice, formulation, dose, anupana and duration should follow the authenticated product and an individualized assessment. Kalmegha should not delay medical evaluation of persistent fever, breathing difficulty, dehydration, severe throat pain, suspected pneumonia or illness in a young child. Consult a qualified Ayurvedic practitioner or healthcare provider rather than copying trial doses for self-treatment.

Conclusion

Kalmegha is an authentic Ayurvedic pharmacopoeial drug with identifiable diterpene lactones and a meaningful but methodologically limited literature for uncomplicated respiratory symptoms. Laboratory studies support anti-inflammatory and antiviral research hypotheses, while human trials mainly support cautious, product-specific symptom-relief claims. The evidence does not justify calling Kalmegha a proven broad-spectrum antiviral or substituting it for diagnosis and standard medical care.

References

  1. Ayurvedic Pharmacopoeia of India
  2. Chandigarh (chandigarh.gov.in)
  3. Ahalia Ayurveda Medical College
  4. A Comprehensive Review of Andrographis paniculata (Burm. f.) Nees and Its Constituents as Potential Lead Compounds for COVID-19 Drug Discovery (2022), PubMed Central
  5. Andrographolide attenuates inflammation by inhibition of NF-kappa B activation through covalent modification of reduced cysteine 62 of p50 (2004), PubMed
  6. Anti-SARS-CoV-2 Activity of Andrographis paniculata Extract and Its Major Component Andrographolide in Human Lung Epithelial Cells and Cytotoxicity Evaluation in Major Organ Cell Representatives (2021), PubMed
  7. Journals (journals.plos.org)
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  9. Use of visual analogue scale measurements (VAS) to asses the effectiveness of standardized Andrographis paniculata extract SHA-10 in reducing the symptoms of common cold. A randomized double blind-placebo study (1999), PubMed
  10. A randomized double blind placebo controlled clinical evaluation of extract of Andrographis paniculata (KalmCold) in patients with uncomplicated upper respiratory tract infection (2010), PubMed
  11. Efficacy of Andrographis paniculata, Nees for pharyngotonsillitis in adults (1991), PubMed
  12. Safety of Andrographis paniculata: A systematic review and meta-analysis (2021), PubMed
  13. Tga (tga.gov.au)