A nosode is a homeopathic remedy prepared from a disease product — the serum of a scabies vesicle, a gonorrhoeal discharge, a culture of tubercle bacilli, carcinomatous tissue — triturated and attenuated exactly as any other remedy is, then prescribed on its own proved symptom picture. The origin is what makes the class unusual; the prescribing rule is not unusual at all, and confusing those two things is the single most common error in this corner of the materia medica. This guide sets out what nosodes in homeopathy actually are, how the classical ones were prepared and proved, when the literature says a nosode is indicated, and where the bowel nosodes fit. It is education for practitioners and serious students, not self-treatment advice.
What a Nosode Is
The word names a source, not a method. Look at how the classical authors head these chapters and the pattern is immediately clear. Boericke calls Psorinum simply "Scabies Vesicle"; Medorrhinum, "The Gonorrhœal Virus"; Tuberculinum, "A Nucleo-protein, a Nosode from Tubercular Abscess"; Syphilinum, "The Syphilitic Virus — A Nosode"; Carcinosinum, "A nosode from Carcinoma." Clarke's Dictionary is equally matter-of-fact: Medorrhinum is "Nosode of Gonorrhœa. Attenuations of the Virus"; Syphilinum, "Luesinum. Lueticum. Syphilitic virus. A nosode. Attenuations."
That is the whole definition. A nosode is a remedy whose starting material is a morbid product rather than a plant, mineral or animal substance. Everything downstream of that — the trituration and attenuation, the proving, the schema of symptoms, the modalities, the differential work — proceeds exactly as it does for Sulphur or Pulsatilla. J. B. Bell, quoted at the end of H. C. Allen's Psorinum chapter, disposed of the squeamishness in one sentence: "Whether derived from purest gold or purest filth, our gratitude for its excellent service, forbids us to enquire or care."
Nosodes are not a shortcut, a class of "stronger" medicines, or a parallel system; they sit alongside the major polycrests rather than above them.
How the Classical Nosodes Were Prepared and Proved
The preparation histories are worth knowing, because they explain some of the confusion in the names.
Psorinum. Clarke records three preparations in a single bracket: "The sero-purulent matter of a scabies vesicle was used by Hahnemann. The product of Psora sicca (epidermoid efflorescence of Pityriasis) by Gross. The salt from a product of Psora by Hering." Triturations. So the psoric nosode reaches us through Hahnemann's own hand and two of the next generation's most careful provers. Clarke's verdict on the resulting proving is unusually strong: "Psorinum has been proved entirely in the potencies, and I know of no more trustworthy proving in the materia medica."
Tuberculinum and Bacillinum. Here the naming genuinely does trip people up, and Clarke sorts it out explicitly. He reserves Tuberculinum for Koch's preparation — "a glycerine extract of a pure cultivation of tubercle bacilli (human)" — while "Burnett's Bacillinum is now accepted as the name of the original homœopathic preparation, and though its originator, Swan, named it Tuberculinum, it owes its present position in therapeutics to Burnett." Clinically he treats them as one: "I do not find any appreciable difference between the action of Tub. and that of Bac… the one will answer to the indications of the other."
Medorrhinum and Syphilinum. Both reach us as attenuations of the virus, and both were proved in potency. Of Medorrhinum, Clarke notes that "the virus has had an extensive proving in the potencies, and the symptoms there recorded have been largely verified in practice." For Syphilinum he credits the chain directly — "I learnt the value of this nosode from Skinner… It has been proved by Swan in the potencies" — and takes his own schema from Hering's. Carcinosin, the fifth, is one of Burnett's preparations (Clarke).
Nosodes Versus Ordinary Remedies: The Rule That Governs Prescribing
Get this right before anything else; it is where the class is most often misused.
Isopathy means giving the potentised disease product for the disease it came from — same to same. Homeopathic nosode prescribing means giving it on similarity of symptoms, whatever the patient's history happens to be. Clarke states the rule in one sentence in his Medorrhinum chapter: "The nosodes may be used according to their indications in exactly the same way as other homœopathic remedies, and not merely for manifestations of the disease from which they are derived."
H. C. Allen closes his Psorinum chapter with the same principle put more sharply: "Psorinum should not be given for psora or the psoric diathesis, but like every other remedy, upon a strict individualization — the totality of the symptoms — and then we realize its wonderful work."
Nash tested the question and reported honestly against the isopathic expectation. He found the nosodes unimpressive when prescribed on the matching history, but recorded "remarkable results from them in cases resembling, for instance, gonorrhœal, syphilitic or psoric troubles, without any history of pre-existing trouble of the kind": itch-like eruptions cured with Psorinum, obstinate rheumatic states with Medorrhinum, "a long standing case of caries of the spine with Syphilinum", in none of which could he trace itch, gonorrhoea or syphilis. He added that others' experience differed, and that he gave only his own.
Clarke gives the complementary case: a knowledge of origin "will often give the clue to the remedy required." Deschere cured a woman of twenty-three of a blepharitis of twelve years' standing with high-potency Medorrhinum, after recalling that he had treated her father for gonorrhoea before the marriage; Skinner traced a boy's intractable favus to the same hereditary cause and cured it with Medorrhinum 1m.
Both are true at once, and together they define the discipline: history raises the nosode as a candidate; the symptom picture prescribes it. And one plain sentence follows from that — a nosode is a prescription made on the totality of an individual case by a qualified practitioner, and it is not a substitute for anything: not for clinical assessment, not for any preventive or public-health measure, and not for the indicated remedy the case actually needs.
When a Nosode Is Indicated
Four situations recur across Boericke, Clarke, Allen and Nash. None of them is a diagnosis; each is a state of the case.
1. Lack of vital reaction
The classical indication, and the one most often meant when practitioners say "this case needs a nosode." Boericke gives it for Psorinum in a single clause — "Lack of reaction, i.e. phagocytes defective; when well-chosen remedies fail to act" — paired with "debility, independent of any organic disease, especially the weakness remaining after acute disease." Allen makes the conditions explicit: Psorinum is for "chronic cases when well selected remedies fail to relieve or permanently improve (in acute diseases, Sulph.)". Note the two qualifiers. The remedies must have been well selected, and the case must be chronic. A nosode is not a rescue for careless prescribing.
2. A convalescence that never begins
The specific form lack of reaction most often takes. The acute illness has resolved, and the patient simply has not come back: appetite absent, sweating on the least exertion, no organic lesion to account for it. Clarke collects reported cases of exactly this — a young woman convalescing from typhoid, "stationary, no appetite", changed immediately by Psorinum 400; a man of fifty who "complained of nothing but weakness… least exertion puts him into a perspiration", cured rapidly (both J. B. Bell). Nash's summary is the bedside version: great debility, sweats on the slightest movement, wants to give up and lie down.
3. A miasmatic or hereditary thread running through an obscure case
Where the case has an inherited or suppressed background that the surface symptoms do not explain — Clarke's blepharitis and favus cases above, or the series Clarke reports from Burnett's book on Delicate Children, in which Syphilinum freed "stunted children from this constitutional blight" (Clarke). Boericke's Medorrhinum picture carries the same theme in its own vocabulary: chronic ailments due to suppressed gonorrhoea, "history of sycosis", children dwarfed and stunted. The theoretical frame for this is miasm theory, which is a subject of its own — our guide to psora, sycosis and syphilis sets it out properly.
4. A well-indicated remedy that will not hold
The case improves, then stalls; the same remedy repeated does less each time. Clarke puts the commonest instance into a single line of his Psorinum Relations: "if Sul. is indicated but fails to act give Pso." Boericke records the equivalent move a step deeper: "When Tuberculinum fails Syphilinum often follows advantageously, producing a reaction." Burnett's much-quoted observation, preserved in Boericke's Tuberculinum chapter, describes a blocked case with a different key: "Vaccinosis may block the way of action of Tuberculin — until Thuja has been given and then acts brilliantly." A useful corrective, because the obstacle is not always nosode-shaped: sometimes the answer is Thuja.
The Classical Nosodes, One by One
Each has a full symptom picture that deserves its own study. What follows is orientation only — the central idea and the confirmatory detail that gets you to the right chapter.
Psorinum
The nosode of psora, and the remedy of lack of vital reaction. Boericke's patient is intensely chilly — "wants the head kept warm, wants warm clothing even in summer", better for heat, worse from cold, from changes of weather and from coffee. The mental state is the psychological face of the failed reaction: "Hopeless; despairs of recovery", melancholy deep, persistent and religious. The second keynote is foulness — the secretions "have a filthy smell", and Clarke notes the body odour "which no amount of washing can remove." Clarke also preserves a strange and very useful confirmatory: "Feels unusually well day before attack." Complementary to Sulphur (Boericke). Full picture: our Psorinum guide.
Tuberculinum
The nosode of change and exhaustion. Boericke's indication is precise and is really a prescribing situation rather than a symptom: "When symptoms are constantly changing and well-selected remedies fail to improve, and cold is taken from the slightest exposure." The subject is light-complexioned and narrow-chested, of "lax fiber, low recuperative powers", always tired, with aversion to work and a want of constant change. Boericke also gives two of the most quoted small confirmatories — averse to meat, desire for cold milk — and, among the mentals, fear of dogs and a desire to use foul language. Worse from motion, from music, before a storm, from damp and draught; better in the open air. Full picture: our Tuberculinum guide.
Medorrhinum
The sycotic nosode, "a powerful and deep-acting medicine, often indicated for chronic ailments due to suppressed gonorrhœa" (Boericke). Its signature is intensity of all sensations with great nervous irritability — Clarke describes a sensibility "exalted almost to clairvoyance." The mental keynotes are the hurry and the distorted time sense: "Time passes too slowly", "is in a great hurry", with weak memory and loss of the thread of conversation. Its modalities are among the most distinctive in the materia medica: worse from daylight to sunset, better at the seashore, better lying on the stomach, better in damp weather, and it sleeps in the knee-chest position (Boericke). Full picture: our Medorrhinum guide.
Syphilinum
The syphilitic nosode, and its two great keynotes are given by Clarke in order. First the night aggravation: "Pains from darkness to daylight; begin with twilight and end with daylight" — an aggravation from sunset to sunrise so reliable that Clarke extends it beyond syphilitic cases, saying neuralgia, headache, asthma and coughs worse from sunset to sunrise "whether syphilitic or not, will be benefited by Syph." Second, ulceration — of mouth, nose, genitals and skin, with fetid pus, and the "succession of abscesses" that he calls "one of the grand keynotes of the materia medica." Boericke adds craving for alcohol and a hereditary tendency to alcoholism, pains that increase and decrease gradually, and the compulsive "always washing the hands." Better inland and in the mountains, worse at the seashore.
Carcinosin
The least-proved of the five and the one to handle with the most reserve, because the classical record is thin: Boericke's whole entry is a claim reported from Clarke, together with indications in carcinoma of the breast and uterus and a note on indigestion, flatulence and "cancerous cachexia." Clarke's own note is more interesting for the practitioner: he used it "more frequently than any other as a diathesic remedy", and observed that "I have met with a suicidal tendency in several cancer patients, so that the cancer nosodes may be appropriate in many mental cases, especially where the heredity points that way." Much of the modern Carcinosin picture is later clinical work and does not come from these sources; when you meet it, check which authority is speaking.
The Classical Nosodes at a Glance
The table uses "worse" and "better" in words rather than the repertory's symbols. Read a row as an orientation, never as a prescription.
| Nosode | Prepared from | Central indication | Modalities | Confirmatory detail | Dose, as the sources give it |
|---|---|---|---|---|---|
| Psorinum | Serum of a scabies vesicle (Hahnemann, via Clarke) | Lack of vital reaction; well-chosen remedies fail to act (Boericke) | Worse cold, weather change, coffee; better heat, warm clothing even in summer (Boericke) | Filthy-smelling secretions; hopeless, despairs of recovery (Boericke); feels unusually well the day before an attack (Clarke) | 200th and higher; "should not be repeated too often" (Boericke) |
| Tuberculinum | Tubercular abscess; Koch's culture of tubercle bacilli (Boericke; Clarke) | Symptoms constantly changing and well-selected remedies fail; takes cold from slightest exposure (Boericke) | Worse motion, music, before a storm, damp, draught, early morning, after sleep; better open air (Boericke) | Averse to meat; desire for cold milk; wants constant change; fear of dogs (Boericke) | 30th and much higher, in infrequent doses (Boericke) |
| Medorrhinum | Gonorrhoeal virus, attenuations (Boericke; Clarke) | Chronic ailments from suppressed gonorrhoea; history of sycosis; intensity of all sensations (Boericke) | Worse daylight to sunset, heat, inland; better at the seashore, lying on the stomach, damp weather (Boericke) | Time passes too slowly; great hurry; sleeps in knee-chest position (Boericke) | "The very highest potencies only of service. Must not be repeated often" (Boericke) |
| Syphilinum | Syphilitic virus, attenuations; proved by Swan in potency (Boericke; Clarke) | Night aggravation and ulceration; succession of abscesses (Clarke) | Worse night, sundown to sunrise, seashore, summer; better inland and mountains, during the day, moving about slowly (Boericke) | Craves alcohol; hereditary alcoholism; always washing the hands (Boericke) | Highest potencies only, infrequent (Boericke); nothing below the 200th, rarely oftener than weekly (Clarke) |
| Carcinosin | Carcinoma; one of Burnett's preparations (Boericke; Clarke) | History of carcinoma elicited, or symptoms of the disease itself (Boericke, citing Clarke) | Not given in these sources | Melancholia; suicidal tendency met with in several cancer patients (Clarke) | 30th and 200th, a dose at night or less frequently (Boericke) |
Two rows in that table teach a whole differential on their own. Medorrhinum is worse from sunrise to sunset and brighter in the evening; Syphilinum is worse from sunset to sunrise. Clarke names this explicitly as "one important point in distinguishing between the sycotic or gonorrhœal taint and that of syphilis". The place modality doubles the contrast: Medorrhinum better at the seashore, Syphilinum worse there and better inland.
Paterson's Bowel Nosodes
The bowel nosodes are a distinct group with a distinct history, and they should not be blended into the classical five. They are prepared from non-lactose-fermenting organisms of the intestinal tract — Paterson describes Morgan as "the type of non lactose organism most frequently found in the stool", and Sycotic Co. as "a non-lactose fermenting coccus", identified in work he published in the British Homœopathic Journal of April 1933 (Paterson). The names record who isolated what: Morgan, Gaertner, Proteus, Dysenteriae, Mutabile and Faecalis are marked (Bach), while Sycotic Co., Bacillus No. 7 and the Morgan sub-types are marked (Paterson).
Each carries a keynote word rather than a symptom list — "Congestion" for Morgan, "malnutrition" for Gaertner, "Brain Storm" for Proteus, "irritability" for Sycotic Co., "Mental and Physical Fatigue" for Bacillus No. 7 — and, the characteristic feature of the method, a group of associated polycrests: Sulphur to Morgan-Pure, Pulsatilla to Mutabile, Sepia to Faecalis (Paterson). Boericke's Psorinum chapter already cross-references Gaertner — "pessimistic, lack of confidence, subjective troublesome eye symptoms, fear of heights. Urticaria. Use 30th and 200th (Wheeler)."
Note where the prescribing weight sits, even for Paterson himself: of Faecalis he writes that "where I have found the organism in the stool, the clinical symptoms have led me to choose Sepia." That is as far as this article goes — his collected papers are the standard English-language source on the group, and are among the 21 classic materia medica books included in the free tier: The Bowel Nosodes.
Potency and Repetition, as the Sources Record It
One pattern runs through every classical nosode chapter: high potency, and rarely repeated. Boericke gives Psorinum as "two hundredth and higher potencies. Should not be repeated too often", and adds the observation, credited in Boericke to Aegedi, that it "requires something like 9 days before it manifests its action, and even a single dose may elicit other symptoms lasting for weeks." Medorrhinum: "The very highest potencies only of service. Must not be repeated often." Syphilinum: "The highest potencies only, and in infrequent doses" — Clarke, independently, says he has "used no potency lower than 200, and rarely repeat the dose oftener than once a week." Carcinosin: "Thirtieth and 200th potency, a dose at night or less frequently."
Tuberculinum is the exception that proves the rule, and even it is qualified. Boericke gives "thirtieth and much higher, in infrequent doses", while quoting H. Fergie Woods to the effect that "Tuberculin needs more frequent repetition in children's complaints than nearly every other chronic remedy." The general principles behind these choices — why a deep-acting remedy is given high and left alone — are covered in our guide to 30C, 200C and 1M.
The same chapters carry cautions of their own, and they belong in the picture rather than in small print. Boericke opens Tuberculinum with a warning that "where skin and intestines do not perform normally even high potencies are dangerous", and preserves Nebel's insistence that it "should not be given without a most careful cardiac examination… especially to children, and seniles", together with a warning against low potencies of the related bacterial toxins because of "terrible aggravations." Nosode prescribing is advanced work that belongs in supervised practice.
Working with Nosodes in the Repertory and Materia Medica
Three habits make this class tractable.
Repertorise the state, not the diagnosis. The situations above convert into repertory rubrics that have nothing to do with the disease the nosode came from: lack of reaction; ailments after acute disease; the constantly changing symptoms that defeat a good prescription. Add the nosode's own distinctive generals — the sunrise-to-sunset or sunset-to-sunrise time modality, better at the seashore, better lying on the abdomen, aversion to meat, craving for cold milk — and the field narrows fast.
Read across authors before you commit. These five vary between authorities more than the polycrests do, and Carcinosin especially carries later clinical material that is not in Boericke or Clarke at all. Reading one nosode across several sources side by side is the surest way to tell a proved symptom from an inherited assumption; the materia medica library is built for that comparison, and Boericke, Clarke, Kent, Allen, Hering and Nash are all in the free tier.
Confirm the picture, then decide. A repertorisation chart that puts a nosode at the top of the column is a prompt to go and read it, not a verdict. The tools narrow the field; the practitioner makes the choice.
Where to Go Next
If you are meeting this class for the first time, take it in three steps. Read the miasm framework once, so the vocabulary of psora, sycosis and syphilis stops getting in the way. Then read one nosode properly rather than five superficially — Psorinum first, because lack of vital reaction is the idea the whole class is organised around. Then read Tuberculinum and Medorrhinum against each other, since their pictures and their time modalities could hardly be more different.
After that the useful work is comparative: open the same nosode in two or three authors in the online materia medica and note where they agree, where they diverge, and which claims rest on a single reported case.
