In short: 30C, 200C and 1M identify different levels of centesimal preparation; 1M conventionally means 1000C. LM/Q is a separate preparation system. Classical authors attach theories of depth, duration and repetition to these labels, but a higher potency number does not establish greater clinical effectiveness or safety.
This guide is for practitioners and students reading homeopathic case records and source texts. It separates three questions: what the label says about preparation, what a named author taught, and what evidence would be needed to support a treatment claim. It provides no universal dosing schedule or self-treatment instructions.
Homeopathy has little supporting evidence for specific health conditions. Symptoms that worsen should be medically assessed, not assumed to indicate a beneficial remedy response. NCCIH’s evidence and safety overview explains that distinction.
What Does Potency Mean in Homeopathy?
A potency label describes a preparation scale and level. In the centesimal system, each serial dilution is nominally 1:100, with succussion, or vigorous shaking, between stages. The number in 30C denotes thirty such stages. A decimal label, such as 6X, uses a different ratio and cannot be compared by its number alone.
Homeopathic literature also uses potency to express Hahnemann’s theory of dynamisation: he proposed that repeated dilution and succussion developed medicinal power. That is the historical explanation for calling a more diluted preparation a “higher potency”. It is not a measurement of pharmacological strength, demonstrated benefit or duration of action.
For an ideal serial dilution, thirty 1:100 stages correspond to a nominal dilution factor of 10 to the power of minus 60. This arithmetic describes the preparation model; it does not measure the contents of a finished product, establish product quality or validate a therapeutic mechanism.
What Is Posology?
Posology is the study of dosage. In homeopathic texts it includes the preparation scale, form, amount, repetition and interpretation of follow-up observations. A potency and a dose are therefore different pieces of information: the label on a vial does not state how much was administered or when.
For source study, record the author, edition and passage together with the terminology. A recommendation in one edition of the Organon should not be combined with a later author’s teaching and presented as one universal Hahnemannian rule. The differences are part of the history students need to understand.
The Potency Scales — X, C, M and LM
Centesimal (C)
The centesimal ratio is 1:100 at each dilution stage. Labels include 6C, 30C and 200C. In common homeopathic notation, 1M denotes 1000C, 10M denotes 10,000C and CM denotes 100,000C. The M here is a count within the centesimal convention, not the LM scale.
CH identifies the Hahnemannian centesimal method. C is the general scale label; CK or K may identify the Korsakovian method. Those methods differ in preparation, so do not infer the full manufacturing process from an abbreviated number in a case note.
Decimal (X / D)
X or D denotes a nominal 1:10 dilution at each stage. Six decimal stages and six centesimal stages therefore represent different nominal dilutions. A lower number does not by itself mean a safer product: the source substance, formulation, actual concentration and manufacturing quality matter.
LM / Q (fifty-millesimal)
LM/Q refers to the system described in §270 of the sixth-edition Organon. Its nominal ratio is approximately 1:50,000 per stage, with a specific process involving trituration and subsequent preparation. It is not simply a centesimal vial with a different letter, nor should a label such as LM1 be read as 1M.
Historical authors discuss LM preparations alongside changes between administrations. Claims that this makes them inherently gentle or particularly suitable for fragile patients are doctrinal claims, not established safety findings.
30C vs 200C vs 1M — A Practitioner’s Comparison
Use this table to interpret a label or a teaching text, rather than to choose a treatment.
| Label | Preparation convention | How it appears in classical teaching | What the label cannot establish |
|---|---|---|---|
| 30C | Thirty centesimal stages | Often discussed in introductory centesimal teaching | A safe default, a condition-specific benefit or a repetition interval |
| 200C | Two hundred centesimal stages | Some schools call it a higher or deeper potency | Greater effectiveness, longer clinical action or a defined aggravation risk |
| 1M | Conventionally 1000C | Often discussed in later high-potency teaching | A proven constitutional effect or suitability for a particular patient |
| LM/Q | Distinct fifty-millesimal process | Associated with the sixth-edition Organon and modified repetition | Proven gentleness, comparative safety or a patient dosing schedule |
30C vs 200C: Which Is Stronger?
“Stronger” is ambiguous. If the question concerns nominal dilution, 200C is more diluted. If it concerns the vocabulary of a classical school, that school may call 200C higher or deeper. If it concerns a clinical outcome, neither label supplies the evidence needed to answer.
Physical or mental-emotional depth, duration and aggravation risk are not established comparative properties of these labels. A useful source comparison identifies who makes such a claim and on what basis, rather than repeating it as a measured fact.
How Classical Authors Discuss Potency Selection
Hahnemann discusses dose and individual response in §§275–287 of the sixth-edition Organon. Kent discusses related ideas within his own philosophical framework. These texts are primary evidence for what their authors taught; they are not controlled demonstrations that a particular potency benefits a particular patient.
When comparing their accounts, ask:
- Which edition and passage? Identify the actual source, not a quotation attributed generally to “the classics”.
- Which preparation? Distinguish dry or liquid descriptions and centesimal or LM terminology without turning the passage into instructions.
- Which claim? Separate a preparation fact from an author’s theory about susceptibility, vitality or action.
- What observation supports it? A case narrative may record improvement after an intervention without establishing that the intervention caused it.
For students, this is a source-reading task that follows case-taking documentation and repertory study. Terms such as “vital force” and “constitutional depth” belong to the authors’ conceptual systems; they should not replace a medical assessment or medication review.
Keep the source and the record together. Similia’s Free plan includes seven classical repertories, 21 classic materia medica books, semantic search, and three new cases plus three analyses per month. Use repertory search to inspect references and record the source behind an observation. AI case analysis and the other AI toolkit features require Pro.
Repetition, Single Dose and the LM Method
The history contains different approaches to repetition. It is inaccurate to reduce §§245–248 to “never repeat during improvement”: sixth-edition §248 describes modified repetition while improvement continues. It is equally inaccurate to turn that passage into a modern schedule for every preparation or patient.
Compare the fifth- and sixth-edition passages side by side and note their qualifications. The point of the exercise is to understand the change in Hahnemann’s method, not to choose between daily, weekly or fortnightly schedules. A potency label alone supports none of those intervals.
“Plussing” in later homeopathic usage refers to modifying a preparation in water with further succussion between administrations. Describing the method does not substantiate claims that it prevents adverse reactions or makes repeated treatment safe. This page therefore gives no preparation recipe, dose quantity or repetition timetable.
Homeopathic Aggravation — Interpretation and Assessment
Classical literature uses homeopathic aggravation for an increase in existing symptoms interpreted as part of a remedy response. Related discussions distinguish new symptoms and the return of previous symptoms. These are interpretive categories within that literature, not reliable tests of whether treatment is working.
A symptom can change because of the underlying illness, another treatment, an adverse effect or unrelated variation. The timing of a change after taking a product does not establish its cause. Deterioration must not be dismissed as a favourable reaction or used to justify delaying appropriate healthcare assessment.
For a follow-up record, keep the observation separate from the interpretation: what changed, when, how severely, what else was being taken, and what assessment or action followed. Record “pain increased on Tuesday” before recording an author’s proposed explanation. This makes a case record more useful to another professional and prevents a doctrinal label from replacing the observed facts.
Choosing Potency in Your Repertory and Materia Medica Workflow
A useful learning workflow is to compare the same source question across records:
- Open a named materia medica source, such as a classical entry discussed in the Arsenicum guide.
- Record its author, title and section. If an edition or method is not specified, record that uncertainty.
- Separate the reported symptom picture from any potency or repetition statement. Neither a repertory grade nor a remedy match measures treatment effectiveness.
- Compare a second author’s account using the materia medica and repertory explainer.
- Keep exact observations, source interpretation and clinical decisions in distinct parts of the record. Never alter an existing medical treatment on the basis of a study exercise.
This approach preserves what is useful in classical posology: a precise vocabulary, an identifiable source and a reviewable record. It avoids assigning unverified levels of safety or benefit to a number on a vial.
Explore the classical sources. Read the 21 classic books in Similia’s public library. Free accounts include seven classical repertories, semantic search and three new cases plus three analyses monthly. Pro adds premium sources, unlimited cases and analyses, and the AI toolkit, including AI case analysis. Software suggestions support reference work; they do not establish a diagnosis, remedy or dose.
References and scope
- Hahnemann, S. Organon of Medicine, sixth edition: §§246–248 on repetition, §270 on preparation, and §§275–287 on dose. Digitized fifth- and sixth-edition repetition passages.
- Kent, J. T. Lectures on Homoeopathic Philosophy. Historical philosophical context, not a clinical dosing guideline.
- NCCIH: Homeopathy, for current evidence and safety context.
- FDA: Homeopathic Products, for label and product-quality context. FDA notes that some labelled products contain measurable active ingredients and that no homeopathic products are FDA-approved.
