International Journal of Homoeopathic Sciences

Background: Potency selection remains central to the philosophy and practice of homoeopathy. While the centesimal (C) scale, developed by Hahnemann in the 5th edition of the Organon, has dominated practice worldwide, the LM (Q) potency scale introduced in the 6th edition was intended as a refinement to address limitations such as strong aggravations, difficulties in repetition, and the need for individualized dose-adjustment.
Objective: This review critically examines the theoretical foundations, pharmacy preparation, and clinical evidence regarding centesimal and LM (Q) potencies.
Methods: Literature from PubMed, Scopus, AYUSH portals, and CCRH databases (2000-2025) was reviewed, along with primary homoeopathic texts. Comparative data were extracted from RCTs, observational studies, case reports, and pharmaco-technical descriptions.
Results: Centismal potencies provide rapid and often intense action but are associated with aggravations in sensitive individuals. LM potencies allow flexible, frequent repetition in aqueous solution, leading to gentler action. Evidence from CCRH trials, dermatology studies, migraine research, and practitioner surveys suggests that LM potencies reduce aggravations while maintaining efficacy. Centismal potencies remain preferred for acute, high-intensity conditions. High-quality RCTs directly comparing both scales remain limited.
Conclusion: Both centesimal and LM potency scales have unique clinical niches. Centismal potencies are powerful, rapid, and remain globally dominant; LM potencies offer gentleness, adaptability, and reduced aggravations. High-quality comparative trials are urgently required to guide potency selection scientifically.