Tier 1 PolychrestGrade CBy Marco RuggeriJune 15, 2026

Nitric Acid — Homeopathic Remedy Profile

Nitricum acidum is the aqua fortis of the old alchemists — corrosive nitric acid, the solvent that eats into metal and flesh alike, brought into homeopathic use by Hahnemann and proved into one of the great remedies of the mucocutaneous border. Its sphere is the margin where skin meets membrane: the corners of the mouth, the rim of the anus, the edge of the genitals. There it produces ulcers with ragged edges, fissures that tear, and a pain so peculiar — sharp, sticking, as if a splinter were lodged in the flesh — that the symptom alone often decides the prescription.

At a Glance

  • Kingdom: Mineral (a mineral acid, prepared from dilute nitric acid)
  • Abbreviation: nit-ac.
  • Common potencies: 3X, 6C, 30C, 200C
  • Evidence grade: C (Traditional/Materia Medica)
  • Key theme: Splinter-like pains, ragged ulcers and fissures at the orifices, offensive discharges, the vindictive, despairing temperament

Source and Preparation

Nitric acid — HNO₃, the aqua fortis of the medieval workshop — is a colorless, fuming, intensely corrosive liquid that dissolves most metals and chars organic tissue on contact. Old-school medicine used it directly as an escharotic, painting it on warts and warty tumors, on phagedenic ulcers, on chancres and poisoned bites, to burn away diseased tissue. That same destructive affinity, potentized, becomes the remedy's curative signature: where crude nitric acid eats a ragged hole in living flesh, the dynamic preparation answers the ragged, eroding ulcer.

The remedy enters the pharmacopoeia by Hahnemann's standard route for the mineral acids — dilution in distilled water, then serial succussion and dilution. One clinical caution recurs across the materia medica: the Nitric Acid patient is unusually sensitive to remedies given in high potency, so practitioners tend to begin low and rise cautiously.

The crude poison is no trifle — the histories record a man who merely inhaled its fumes for two hours while neutralizing a fractured bottle and died the next day of inflammation of the lungs. Potentized, that same corrosive intensity turns inward — to the membranes and the temper.

The Essence of Nitric Acid

Three things make a Nitric Acid case, and when they appear together the prescription is almost forced. First, the splinter pain: a sharp, sticking sensation, as though a sliver had pierced the part — in ulcers, in fissures, in the throat on swallowing, under an ingrown nail, even in a wart. Second, the ulceration at the outlets — margins of mouth, anus, and genitals — with edges ragged, irregular, zigzag, easily bleeding, the base like raw flesh. Third, the temperament: irritable, hateful, vindictive, holding grudges, unmoved by apology, anxious to the point of obsession about his own health, and prone to a hopeless despair of recovery.

The unifying thread is erosion. Crude nitric acid corrodes whatever it touches; the patient is corroded from within. Tissue erodes into ragged ulcers. Discharges turn acrid and corrosive — caustic enough to redden the skin they run over and destroy the hair they touch. And the mind erodes too: resentment that will not heal, an old offense kept raw, a grievance picked at like a sore that never closes. Murphy is exact — the patient "constantly thinks about past troubles," is "unmoved by apologies," carries "inveterate ill-will" and "hatred of persons who had offended." The grudge is a fissure in the soul. It tears and does not close.

Nitric Acid belongs, in the old classification, almost equally to all three of Hahnemann's miasms — psora, syphilis, and sycosis — and its breadth comes from this: the fissures and sore mouth of psora, the eroding ulcers and chancres of the syphilitic taint, the warts, condylomata, and offensive discharges of sycosis. It is one of the chief antidotes to Mercury, and a leading remedy for those whose constitutions have been overdosed with mercury or wrecked by repeated courses of antibiotics. The typical patient is dark, swarthy, black-haired and black-eyed, lean, of rigid fiber, nervous, chilly, catching cold at the least exposure and falling into diarrhea with every cold.

What the remedy answers, then, is not a single complaint but a manner of suffering: violent reaction to slight cause, sticking pain out of all proportion, discharges that offend the room, and a temper that will not forgive. The man who walks the floor for hours after a soft stool, who is convinced he is mortally ill while no organ is failing, who has not spoken to his brother in eleven years over a wrong neither can now name — that man is asking for Nitric Acid.

Clinical Portrait

Mind and Temperament

The mental picture is one of the most distinctive in the materia medica, and in my practice it is what most often confirms the remedy. The patient is irritable, hateful, vindictive, headstrong. Anger flares violently — fits of rage and cursing, profane language, trembling with fury while quarrelling. But the rage is not the openhearted, blow-over storm of Chamomilla. It is cold and durable. He holds grudges and broods on past wrongs. An apology does not reach him; he is, in Murphy's phrase, "unmoved by apologies," carrying "inveterate ill-will" toward whoever has offended.

Beneath the hostility lies fear that fixes on the body. Anxiety about health is a keynote — fixed ideas that he has a disease, obsessive dread of cholera or some named affliction, a despair that shades into hopelessness about ever recovering. He is extremely pessimistic, discontented with everything and with himself; a suicidal disposition couples, paradoxically, with a fear of death. He refuses consolation when his misfortunes are mentioned — and here he meets Natrum Muriaticum, though Natrum's grief is silent and inward where Nitric Acid's is bitter and accusing.

The mind grows weak under strain: memory fails, thoughts vanish after mental effort, confusion sets in, and there is no disposition to work or undertake any serious business. The ailment so often traces back to a particular cause — the exhaustion of nursing a sick loved one through long nights, the wearing strain of night-watching and chronic loss of sleep. The remedy stands beside Cocculus and Nux Vomica in this etiology of the worn-out carer turned bitter.

Head and Sensorium

Headache in Nitric Acid has a constricting, crushing quality — a band around the head, or the head held as if in a vice from ear to ear over the vertex, bound tight by a tape. Pains are throbbing, hammering, pulsating, with violent congestion; the skull is sore to the touch, the scalp sensitive. A characteristic aggravation: headache from the pressure of a hat. Street noise, the rattle of wagons, the jar of someone walking across the room all make it worse. And here appears the remedy's most surprising modality: the headache, like nearly every other symptom, is better from riding in a carriage. The gliding motion soothes what jarring inflames.

Vertigo is frequent through the day — with dimming of sight, with nausea followed by belching, with weakness that forces the patient to sit down, worse on raising the head after stooping.

Mouth, Throat, and Teeth

This is one of the remedy's home territories, and the splinter pain announces itself here most plainly. Ulcers form in the soft palate with sharp, splinter-like pains; blisters and ulcers stud the mouth, tongue, and lip margins, all bleeding easily. The corners of the mouth are raw, cracked, scabby. Gums are swollen, soft, spongy, bleeding on the inner side; the breath is putrid; the saliva bloody, the tongue carrying a green coating with a central furrow and so sensitive that even soft food causes smarting.

In the throat the picture sharpens: dryness and heat, rawness as if ulcerated, and "sharp pains, as from splinters, on swallowing" — the patient feels each swallow as though a fishbone were lodged in the fauces. The tonsils are red, swollen, uneven, dotted with small ulcers; the pain shoots from throat into ears. The teeth feel elongated, loose, "soft and spongy," yellow and decaying, aching on anything cold or hot.

Rectum and Anus

If I had to name the single complaint Nitric Acid has cured most reliably in my own practice, it is the anal fissure. The picture is unmistakable and brutal. The bowels are constipated, with fissures in the rectum; there is great straining but little passes. Tearing pains accompany the stool — and the cruelty of it is that the stool tears the anus even when soft. The patient does not escape by keeping the stool loose; rawness and soreness of the anus accompany the diarrhea too.

The cardinal symptom comes after the stool: violent cutting pains that last for hours, so that the patient "walks in agony," pacing the floor, unable to sit, as though the anus and rectum had been torn and pierced. This protracted post-defecation agony — sometimes lasting the better part of a day for a single stool — is among the most characteristic symptoms in the entire materia medica, distinguishing Nitric Acid at a stroke from Ratanhia, which shares the long after-pain but lacks the wider grudging, eroding constitution. The patient is irritable and exhausted after stool, dreading the next.

Hemorrhoids bleed easily — bright, profuse blood after stool, sometimes a dessert-spoonful, sometimes half a teacup. There is burning in the rectum, often worse after urination; the anus itches, oozes moisture, becomes eczematous; anal warts and condylomata gather at the rim. Diarrhea is slimy, green, offensive — and diarrhea from antibiotics or penicillin is a recognized modern indication, fitting the remedy's broader role in restoring constitutions deranged by drugging. J. H. Fulton recorded a clean cure: a man of twenty-eight with eighteen months of bleeding hemorrhoids, bright red blood after slimy stools and much pain when the stool was hard, cleared on a single dose of 200C.

Urinary and Genital

The urine carries the remedy's most quoted keynote: intensely offensive, it "smells strong as a horse's." It may feel cold as it passes, run alternately profuse and scanty, or turn bloody and albuminous; there may be painless retention or incontinence, the stream thin as if from a stricture. With Benzoic Acid as its nearest rival, the strong horse-urine odor is one of the small unmistakable pointers of materia medica.

In the male, ulcers on the prepuce and glans burn and sting and exude offensive matter; chancres turn phagedenic; there is phimosis, edema of the foreskin, red scurfy spots on the corona. In the female, menses come early and profuse, "like muddy water," with pain in back, hips, and thighs; leucorrhea is brown, flesh-colored, watery or stringy, staining yellow and leaving spots with a black border; uterine hemorrhages follow childbirth, abortion, or curetting, often in pale, cachectic women. H. N. Coons cured an anemic woman of constant pelvic hemorrhage four weeks after miscarriage with 2X in water; the bleeding stopped quickly.

Skin, Warts, and Ulcers

The skin shows the remedy's eroding signature in full. Warts are large, jagged, and bleed on touch or on washing — the wart that bleeds the moment it is washed in the bath is the classic pointer, usually near a moist orifice with condylomata clustering too. Ulcers bleed easily and are sensitive, carrying the splinter pain; their edges are zigzag and irregular, the base "looks like raw flesh," granulations exuberant, suppuration stubborn and burrowing. Old scars turn painful in cold weather. The skin is dry, eroded, cracked in every angle, and itches on undressing.

The nails are distorted, discolored, yellow, curved, with white spots; ingrown nails ulcerate and carry that same splinter feeling, worse from touch. The feet sweat offensively, the sweat causing soreness of the toes with sticking pain and chilblains.

Respiration and Chest

Shortness of breath on climbing stairs is characteristic — the patient pants on going up, or when reading or stooping, and great dyspnea may leave him unable to talk for want of breath. The chest feels bound by an iron band, with a catching at every attempt to breathe, stitches in the sides, and offensive sweat in the axillae at night. The cough comes from a dry spot in the larynx, worse in cold and winter, continuing through sleep without waking. Nosebleeds are dark and clotted, worse from crying; the nasal discharge is corrosive, yellow, and offensive, the nostrils sore and bleeding, with a tendency to ozaena.

Generalities

A few traits thread through every region. Offensive discharges — urine, feces, sweat, leucorrhea, expectoration — all acrid, thin, corrosive, dirty or brownish-green, not laudable pus. Easy hemorrhages, bright and profuse, especially in cachectic women after confinement or abortion. Extreme sensitiveness to touch and jar through the whole organism, mind included: the head sensitive to the rattle of wagons, to the step of one crossing the floor, to combing the hair; the tongue to soft food; eruptions and ulcers bleeding when merely touched. Chilliness — chills in waves up each side of the spine, icy soles — coexisting with dry internal heat at night that drives the patient to uncover. And over it all, the most reliable general: marked improvement of all symptoms while riding in a carriage.

Modalities

Worse:

  • Touch, jarring, rattling, motion — even the step of someone walking across the floor
  • Cold air, cold climate, damp, changing weather
  • Heat of the bed and hot weather (worse from both temperature extremes — a peculiar, useful contradiction)
  • Evening and night
  • Mental exertion, shock, noise
  • Milk and fatty food; after eating
  • Loss of sleep, night-watching, nursing the sick
  • Mercury and the after-effects of antibiotics

Better:

  • Riding in a carriage, and gliding motion generally (the keynote amelioration)
  • Steady, firm, continuous pressure
  • Mild, settled weather

The double aggravation from cold and heat sets the remedy apart. Most chilly remedies want warmth; most warm-blooded ones want cool. Nitric Acid is comfortable in neither — worse from cold air and cold climate, yet equally worse from the heat of the bed and hot weather, wanting to throw off the covers in the dry internal heat of night. Add the carriage-ride amelioration to this thermal contradiction and the remedy is nearly named.

Remedy Relationships

These relations are drawn directly from the remedy's materia medica and not extrapolated.

Complementary

  • Calcarea Carbonica: compatible both before and after Nitric Acid, and one of its antidotes — the deeper chilly, sycotic-tinged constitution that often underlies the case.
  • Pulsatilla: compatible before and after; a frequent partner in the slow unwinding of sycotic, discharge-laden states.
  • Sulphur: compatible before and after, and a classic complement in scrofulous and suppressed cases.
  • Thuja: compatible after Nitric Acid and the nearest remedy in the sycotic sphere — condylomata, enlarged tonsils, fissures, greenish leucorrhea. The two often follow one another in warty, condylomatous disease.

Antidotes

Compare

  • Mercurius Solubilis: The closest and most important comparison. Both have sore mouth and throat, offensive discharges, ulcers, and bleeding spongy gums. But Mercury is worse at night and from the heat of bed with profuse sweat that gives no relief, while Nitric Acid carries the splinter pain, the carriage amelioration, and the grudging vindictiveness. When a Mercury picture has been overdrugged or fails to hold, Nitric Acid completes it.
  • Thuja: For condylomata, fissures, enlarged tonsils, and greenish leucorrhea. Thuja's warts are softer and more pedunculated; Nitric Acid's are jagged, bleed on washing, and carry the splinter pain Thuja lacks.
  • Hepar Sulphuris and Argentum Nitricum: the three great splinter-pain remedies. Hepar's comes with exquisite cold-sensitivity and a craving to suppurate cleanly; Argentum Nitricum's with anticipatory anxiety and a craving for sweets that disagree; Nitric Acid's with ragged ulcers at the orifices and offensive discharges.
  • Mezereum: shares the eroding, crusting skin and bone pains; useful in secondary syphilis, where it follows Nitric Acid well.
  • Arsenicum Album: shares the anxious obsession with health and the diarrhea with every cold, but Arsenicum's restlessness and burning relieved by heat contrast with Nitric Acid's splinter pains and double thermal aggravation.
  • Kali Carbonicum and Muriatic Acid: also listed among the comparisons; Muriatic Acid shares the deeply offensive, prostrating, ulcerative states, where Nitric Acid is set apart by the splinter pain and carriage relief.

Clinical Uses

Mouth Ulcers

For mouth ulcers, Nitric Acid is the remedy of the splinter sensation — the ulcer, typically on the soft palate or lip margins, feels as though a sharp sliver were lodged in it, bleeds easily on touch, and sits in a mouth with putrid breath and soft, spongy, bleeding gums. The pain is sharp and sticking rather than burning, which separates it from Arsenicum Album (burning, better for warm drinks); the easy bleeding with offensive breath separates it from Borax (superficial white aphthae) and Mercury (close, but lacking the splinter quality). 30C two or three times daily is a reasonable acute range. Nitric Acid is featured in our guide to the best homeopathic remedies for mouth ulcers.

Warts and Condylomata

Among the leading remedies for warts, Nitric Acid answers the jagged wart that bleeds on washing. Murphy is precise: "warts, large, jagged, bleed on touch or washing," with condylomata at the moist orifices and the signature splinter pain. The wart that bleeds the moment it meets the washcloth is the classic pointer; warts on the backs of the hands are also recorded. This distinguishes it from Thuja (soft, spongy, pedunculated or cauliflower-form warts, often after vaccination) and Causticum (seedy, large, jagged warts that bleed easily and ulcerate, found on fingertips, eyelid margins, and nose — but lacking the splinter pain and offensive-discharge constitution of Nitric Acid). 30C daily, or 200C spaced, are typical. Nitric Acid is featured in our guide to the best homeopathic remedies for warts.

Hemorrhoids and Anal Fissure

Nitric Acid is one of the foremost remedies for the cluster of complaints around the anus — hemorrhoids, anal fissure, proctitis, and prolapse. The defining symptom is the violent cutting pain after stool that lasts for hours, driving the patient to walk the floor in agony, with the stool tearing the anus even when soft. Hemorrhoids bleed easily, bright and profuse, with burning in the rectum after stool and often after urination. Where Nux Vomica has ineffectual urging and Ratanhia has the long after-pain without the wider eroding state, Nitric Acid joins the protracted post-stool agony to the offensive, vindictive constitution. 30C two or three times daily suits an active fissure; a single 200C has cured chronic bleeding hemorrhoids, as in Fulton's case. The remedy equally answers diarrhea following antibiotics, with rawness and soreness of the anus.

Effects of Mercury, and Chronic Sycotic Ulcers

A use too valuable to omit: Nitric Acid is one of the chief antidotes to Mercurius and the leading remedy for constitutions damaged by overdosing with mercury, or by repeated antibiotics — the bleeding spongy gums, loose teeth, sore mouth and throat, offensive discharges and bone soreness of a mercurialized patient point straight here. The same remedy answers ragged, easily bleeding ulcers with splinter pains and exuberant granulations on skin, mouth, or genitals, and the broader sycotic picture of condylomata, greenish discharges, and enlarged tonsils — often in sequence with Thuja or Sulphur.

Frequently Asked Questions

What is the single most reliable Nitric Acid keynote?

The splinter pain — a sharp, sticking sensation, as if a sliver were lodged in the part, felt in ulcers, fissures, the throat on swallowing, even in a wart. When this joins ulceration at the margins of mouth, anus, or genitals and markedly offensive discharges, the remedy is nearly named. Amelioration of nearly everything from riding in a carriage is the confirming general.

How do I tell Nitric Acid from Mercurius in a sore mouth?

Both have spongy bleeding gums, foul breath, ulcers, and offensive discharges. The deciding features are the splinter quality of the Nitric Acid pain, the carriage amelioration, and the temperament — Nitric Acid holds grudges and despairs of recovery, where Mercury is changeable and creeping. Mercury is decidedly worse from the heat of the bed at night with drenching sweat; Nitric Acid is worse from both heat and cold. When a Mercury case has been overdosed with mercury, Nitric Acid is the remedy that follows.

Why does the carriage ride matter so much?

It is the remedy's great paradox. Almost everything in Nitric Acid is worse from jarring — touch, the rattle of wagons, the step of someone crossing the floor — yet the patient is markedly better riding in a carriage, where the motion is gliding rather than jolting. The same logic explains the relief from steady, firm pressure. When a patient otherwise hypersensitive to jar tells you a long drive eases their whole state, think of Nitric Acid.

References

  1. Murphy, R. Nature's Materia Medica. 3rd ed. Lotus Health Institute, 2006. Nitricum acidum.
  2. Boericke, W. Pocket Manual of Homoeopathic Materia Medica. 9th ed. B. Jain Publishers, 2002. Nitricum acidum.
  3. Clarke, J.H. A Dictionary of Practical Materia Medica. B. Jain Publishers, 2005. Nitricum acidum.
  4. Kent, J.T. Lectures on Homoeopathic Materia Medica. B. Jain Publishers, 2006. Nitri acidum.
  5. Hahnemann, S. The Chronic Diseases, Their Peculiar Nature and Their Homoeopathic Cure. B. Jain Publishers reprint, 2005. Acidum nitricum.
  6. Hering, C. The Guiding Symptoms of Our Materia Medica. B. Jain Publishers, 1997. Nitri acidum.
  7. Phatak, S.R. Materia Medica of Homoeopathic Medicines. 2nd ed. B. Jain Publishers, 1999. Nitricum acidum.