Allium cepa: keynotes and uses
Allium cepa — the common red onion — reproduces in the healthy what it cures in the sick: a streaming cold or hay fever with a burning, acrid nasal discharge and profuse but bland tears.
The source and its place in the materia medica
Allium cepa is prepared from the fresh bulb of the cultivated red onion (Amaryllidaceae), tinctured and then potentised by serial dilution and succussion in the standard Hahnemannian or Korsakovian methods. The remedy is a clean illustration of the law of similars: the substance that, raw, makes healthy eyes and nose stream is the one that resolves the same picture when it arises in disease.
Hering proved it; Boericke and Kent expanded it from their casebooks. Across two centuries the remedy has held a narrow niche — acute coryza, hay fever, and a particular raw, tickling cough. It is the standard teaching partner to Euphrasia, because the two invert each other's discharge picture.
Keynotes
The single discriminating feature is the contrast between an acrid, excoriating nasal discharge and bland, non-irritating tears — the mirror image of Euphrasia. The features below recur with enough consistency across Boericke, Hering, and Kent to function as a reliable checklist.
| Keynote dimension | What the remedy shows |
|---|---|
| Nose | Profuse, watery, acrid discharge that burns and reddens the upper lip |
| Eyes | Profuse, bland tears that do not irritate |
| Sneezing | Violent and repeated, worse in a warm room |
| Cough | Raw, tickling; the patient grasps the larynx for the pain |
| Direction | Symptoms often move from the left side to the right |
| Modalities | Worse indoors and in a warm room; better in open air |
Boericke captures the contrast in a line: acrid nasal discharge, but bland lachrymation; the reverse of Euphrasia. Allium cepa is an acute, short-arc remedy for the running-nose presentation, not a constitutional prescription.
Indications
- The early acute cold with a burning, streaming nose that excoriates the upper lip.
- The nose-dominant form of hay fever where the nasal discharge is markedly acrid.
- A raw, tickling laryngeal cough that worsens in cold air and causes the patient to clutch the throat.
- Catarrhal states that improve markedly on going outdoors into the open air.
The usual prescription is 6C or 30C in the acute phase, with a watch-and-observe window of a day or two.
Differentials
Allium cepa sits alongside Euphrasia and Sabadilla in the acute coryza and hay-fever pictures. The differential turns on which membrane carries the acrid discharge.
| Dimension | Allium cepa | Euphrasia | Sabadilla |
|---|---|---|---|
| Acrid discharge | From the nose; burns the lip | From the eyes; tears burn | Spasmodic sneezing leads |
| Bland discharge | From the eyes | From the nose | Variable |
| Worse | Warm room; better open air | Open air, wind, light | Cold air; better warmth |
| Lead symptom | Streaming irritated nose | Streaming irritated eyes | Violent paroxysmal sneezing |
One axis — which membrane carries the acrid discharge — separates the three.
Safety
The dispensed potencies are 6C and above. The starting substance is a food, and the higher potencies carry essentially the safety profile of the lactose or ethanol carrier.
A cold or hay fever that worsens rather than settles, high or persistent fever, breathing difficulty, chest pain, an earache that does not resolve, or any respiratory symptom in an infant, an older patient, or someone with asthma or another chronic condition is a red-flag presentation needing prompt clinical assessment alongside any acute prescribing.
Looking up the rubrics
The rubric burning nasal discharge anchors the Allium cepa picture; bland tears separates it from Euphrasia — both reachable through the free repertory.
References
Hahnemann, S. (1811–1821) Materia Medica Pura, multiple volumes; reprint edited by R. E. Dudgeon (1880), London: Hahnemann Publishing.
Boericke, W. (1927) Pocket Manual of Homoeopathic Materia Medica with Repertory, ninth edition, Philadelphia: Boericke & Tafel; entry on Allium cepa.
Clarke, J. H. (1900) A Dictionary of Practical Materia Medica, three volumes, London: Homoeopathic Publishing Company; Allium cepa entry.
Hering, C. (1879–1891) The Guiding Symptoms of our Materia Medica, ten volumes, Philadelphia: F. E. Boericke; Allium cepa entry.
Kent, J. T. (1905) Lectures on Homoeopathic Materia Medica, Philadelphia: Boericke & Tafel; remarks on Allium cepa, Euphrasia, and Sabadilla.