Centesimal Scale

The centesimal scale is the most widely used potency scale in homeopathy. At each step of potentization, one part of the preparation is diluted in ninety-nine parts of vehicle and then vigorously succussed. The resulting potencies are denoted by the letter C — for example, 6C, 30C, 200C, or 1M (one thousand centesimal).

In Practice

When a practitioner prescribes Arnica 30C, the remedy has been through thirty complete cycles of centesimal potentization. At each cycle, one part of the previous stage was added to ninety-nine parts of fresh purified water-alcohol solution in a clean glass vial, then succussed a specified number of times.

The centesimal scale spans a wide range of clinical applications. Low centesimal potencies (6C, 12C) are commonly used for acute physical complaints and for patients whose sensitivity is uncertain. The 30C potency is among the most commonly used potencies — versatile enough for both acute and chronic presentations. Higher centesimal potencies (200C, 1M, 10M) act more deeply and for longer durations, reaching the mental and emotional levels more decisively. Practitioners select along this spectrum based on the individual case, the patient's vitality, and the certainty of the remedy match.

Two distinct methods exist for preparing centesimal potencies. The Hahnemannian method uses a fresh vial at each step, ensuring a precise 1:100 ratio. The Korsakovian method, developed later, reuses a single vial — the liquid clinging to the glass walls after emptying serves as the carried-over portion. Pharmacopoeias specify which method applies at different potency ranges. In most traditions, Hahnemannian preparation is standard for lower potencies, while Korsakovian preparation is accepted for higher ones.

The centesimal scale has been the dominant scale in homeopathic practice since Hahnemann established it, and it remains the default reference point when practitioners discuss potency selection.

Related Terms

• Potency — the level of preparation expressed as a number on a given scale
• Decimal Scale — an alternative scale using a 1:10 dilution ratio
• LM Potency — Hahnemann's later scale using a 1:50,000 ratio
• Potentization — the combined process of dilution and succussion

Learn More

• Potency Guide — practical guidance on selecting centesimal and other potencies
• How Homeopathic Remedies Are Made — the preparation process in detail