Posology

Posology is the branch of homeopathic therapeutics concerned with dosage in its fullest sense — not merely the quantity of substance administered, but the selection of potency, the frequency of repetition, and the method of administration. It is central to case management and, alongside remedy selection itself, one of the areas where clinical skill most directly influences outcomes.

In Practice

Choosing the correct remedy is only half of the prescribing decision. The same remedy given at the wrong potency, repeated too frequently, or administered by an unsuitable method can produce a poor result even when the remedy selection is accurate. Posology addresses all of these variables.

Potency selection involves choosing from the centesimal scale (6C, 30C, 200C, 1M), the decimal scale (X/D potencies), or the LM/Q scale introduced in the sixth edition of the Organon of Medicine. Lower potencies are generally used for conditions with strong physical pathology; higher potencies when the mental-emotional picture is clear and vitality is good. LM potencies offer a middle path — gentle enough for sensitive patients yet capable of deep action in repeated liquid doses.

Repetition refers to how often the dose is given. The frequency of repetition varies widely depending on the nature of the case, the potency used, and the patient's sensitivity. The principle of the minimum dose guides repetition decisions: the least amount of stimulation sufficient to initiate a healing response.

Method of administration includes dry dosing (pellets on the tongue), liquid dosing (remedy dissolved in water), and the plussing method — succussing the solution before each dose to slightly modify the potency. Hahnemann came to prefer liquid dosing with succussion in his later practice, finding it produced smoother results with less aggravation.

These three elements interact, and experienced practitioners adjust them as a system. This flexibility is what makes posology both a science and an art within homeopathic practice.

Historical Context

Hahnemann's posological thinking evolved dramatically over his career. His early practice used crude doses and low potencies; by the time of the fifth edition of the Organon (1833), he advocated single doses of high centesimal potencies with long waiting periods. The sixth edition (completed 1842) introduced the LM scale and the plussing method, representing his most refined posological approach — one that balanced the need for gentle action with the ability to repeat doses frequently in chronic cases.

Related Terms

• Minimum Dose — the guiding principle behind potency and repetition decisions
• Plussing Method — the liquid dosing technique that refines dose repetition
• Aggravation — a potential consequence of incorrect posological choices
• Organon of Medicine — the text where Hahnemann's posological evolution is documented

Learn More

• Potency Guide — a practical overview of potency scales and their applications
• Minimum Dose — the principle that underpins all posological decisions