Zinc sulfate
Pronunciation: zink SUL-fate.
- Generic name
- zinc sulfate
- Brand names
- ZINCAPS, Zinc Plus, Zinc Sulphate (Phebra)
- Drug class
- Zinc salt / mineral supplement (trace-element replacement)
- Form
- Oral tablets/capsules (commonly 110 mg or 220 mg zinc sulfate, providing 25 mg or 50 mg elemental zinc); 0.25% ophthalmic solution (combination eye drops); sterile injectable solution for pharmacy compounding only
- Route
- Oral (tablet/capsule, most common); also available as an OTC ophthalmic astringent (eye drops) and, separately, as a prescription-only injectable additive for parenteral nutrition
- Legal status
- Oral form: OTC dietary/mineral supplement in all markets reviewed. A separate injectable form (for parenteral/IV nutrition) is prescription-only and never self-administered.
Supply Rules Vary
Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand
Australia: Zinc Plus and other AUST L-listed zinc sulfate products (7), Zinc Sulphate (Phebra) (7) · Full directory
What zinc sulfate is and how it works
Zinc sulfate is a zinc mineral salt most commonly taken by mouth as an over-the-counter dietary supplement to treat or prevent zinc deficiency and to support normal immune function. It is classified as a food supplement or Natural Health Product (not a disease-treatment medicine) in every market reviewed for the oral form. Two other, quite different zinc sulfate products exist: a prescription-only sterile injectable additive that pharmacy staff compound into intravenous (parenteral) nutrition for patients who cannot get enough zinc through the gut, and an over-the-counter ophthalmic astringent (0.25% concentration) used in combination eye-redness-relief drops. Zinc sulfate must never be used in the nose: nasal (intranasal) zinc products, including zinc sulfate nasal spray, have a real, decades-documented risk of causing loss of the sense of smell (anosmia), first reported in the medical literature in 1938. (1) (2) (3) (4)
Most people encounter zinc sulfate as an oral tablet or capsule bought without a prescription. If your zinc sulfate has been prescribed as an injectable additive to intravenous nutrition, that is a different, hospital/clinic-managed product, not something you take by mouth or adjust yourself.
What zinc sulfate is used for
Treating or preventing zinc deficiency (oral supplement)
Oral zinc sulfate is used as a dietary supplement to treat or prevent zinc deficiency and to support normal immune system function. It is classified as a food supplement (UK/EU), Natural Health Product (Canada), TGA-listed medicine (Australia), or dietary supplement (US, New Zealand) rather than an approved disease-treatment drug. (1) (6) (7) (8) (9)
Additive for intravenous (parenteral) nutrition — prescription only
A separate, prescription-only sterile zinc sulfate solution is compounded by pharmacy staff into intravenous nutrition (parenteral nutrition) for patients, such as those unable to absorb enough zinc through the digestive tract. This form is not for direct injection on its own and is never self-administered. (2) (7) (9)
OTC eye-redness relief (ophthalmic astringent)
A 0.25% zinc sulfate solution, usually combined with a decongestant such as tetrahydrozoline or naphazoline, is used in over-the-counter eye drops to relieve minor eye redness and irritation. (3)
Before taking zinc sulfate
Do not take / not appropriate for
- Do not use zinc sulfate in the nose (as a nasal spray, gel, or swab) under any circumstances. Intranasal zinc exposure — including zinc sulfate specifically — has a real, long-documented risk of causing sudden and sometimes permanent loss of the sense of smell (anosmia), first reported in 1938. (all forms — this is a route warning, not a product-specific one) (4)
- Do not take oral zinc sulfate at doses above the labelled amount, or for longer than the labelled short-term course, without medical advice — sustained high-dose zinc intake can cause copper deficiency. (oral supplement) (5) (2)
Tell your clinician about
- If you are taking other zinc-containing products (including multivitamins), to avoid unintentionally exceeding the recommended total zinc intake.
- Any history of copper deficiency, anaemia, or low white blood cell count.
- Other medicines you take, since zinc can reduce the absorption of some antibiotics and other minerals if taken at the same time.
- Pregnancy, plans for pregnancy, or breastfeeding.
How to take zinc sulfate
- Oral zinc sulfate tablets/capsules are usually taken once daily with a full glass of water, or with food if it upsets your stomach.
- Follow the dose on the product label or your clinician's/pharmacist's advice; a common adult supplement dose provides 50 mg of elemental zinc daily, but this varies by product and reason for use.
- Do not exceed the labelled dose or duration without checking with a pharmacist or clinician, given the real copper-deficiency risk with prolonged high-dose use.
- Never use any zinc sulfate product in the nose.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7) (8) (9)
Missed dose
If you miss a dose of oral zinc sulfate, take it when you remember unless it is nearly time for your next dose — do not take a double dose to make up for a missed one. If you are unsure, check the product label or ask a pharmacist.
Overdose
Taking much more than the recommended dose of zinc can cause nausea, vomiting, stomach cramps, diarrhoea, and headache, and — if sustained — copper deficiency with its own separate complications (see Serious warnings). Seek medical advice or contact a poison control service if a large overdose is taken, especially in a child. (5)
Side effects
Oral zinc sulfate is generally well tolerated at recommended doses, but can cause stomach-related side effects, and prolonged high-dose use carries a real risk of copper deficiency.
Nausea and stomach upset
What to notice: Feeling sick, mild stomach discomfort, or indigestion, especially if taken on an empty stomach.
What to do: Try taking it with food. Tell a pharmacist or clinician if it continues or is severe. (1)
Metallic taste
What to notice: An unusual taste in the mouth after taking the supplement.
What to do: Usually not a cause for concern; mention it to a pharmacist if bothersome.
Serious warnings
Loss of smell (anosmia) from intranasal zinc exposure — emergency
Symptoms: Sudden reduction or complete loss of the sense of smell, which can occur very rapidly after nasal exposure to zinc, including zinc sulfate.
Action: Never use zinc sulfate in the nose. If it happens anyway, stop immediately and seek medical evaluation. This risk is specific to the intranasal route and has been documented since 1938 — oral tablets/capsules taken as directed are not associated with this particular risk. (4)
Zinc-induced copper deficiency with prolonged/high-dose use — high caution
Symptoms: Unusual tiredness or paleness (anaemia), increased infections (low white blood cell count/neutropenia), and — especially if unrecognised — numbness, tingling, weakness, or poor balance from nerve damage.
Action: Do not use oral zinc beyond the short course described on the label without medical advice. See your clinician promptly for blood tests if you notice these symptoms after high-dose or prolonged use — early recognition matters because the neurological effects can become difficult to reverse. (5) (2)
Severe allergic reaction — emergency
Symptoms: Swelling of the face, lips, tongue, or throat; difficulty breathing; widespread rash or hives.
Action: Seek emergency medical help immediately.
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Certain antibiotics (e.g., tetracyclines, some fluoroquinolones) | Zinc can bind to these antibiotics in the gut and reduce how much the body absorbs, potentially making the antibiotic less effective. | If you need to take one of these antibiotics, ask a pharmacist about spacing the doses apart from your zinc supplement. |
| Other zinc-containing products (e.g., multivitamins, other supplements) | Taking multiple zinc-containing products together can lead to unintentionally exceeding the recommended total daily zinc intake, increasing the risk of copper deficiency and other side effects. | Check the total zinc content of everything you take, and ask a pharmacist if you are unsure. (5) |
| Iron and calcium supplements | Taking zinc at the same time as iron or calcium supplements may reduce absorption of one or both minerals. | Ask a pharmacist about the best timing if you take more than one of these supplements. |
Pregnancy, breastfeeding, kidney/liver function, age
Patients on prolonged or high-dose zinc
Anyone using oral zinc at a high dose or for longer than the short-term course described on the label should be aware of the real risk of copper deficiency and watch for its symptoms (see Serious warnings). (5)
Patients receiving parenteral (IV) nutrition
The prescription injectable form of zinc sulfate is a pharmacy-compounded additive to intravenous nutrition, dosed and monitored by the treating clinical team — it is a different product from the oral supplement and is never self-administered. (2)
Pregnancy and breastfeeding
Specific pregnancy/breastfeeding safety data for oral zinc sulfate supplementation were not detailed beyond general dietary-supplement guidance in the reviewed sources; check with a pharmacist or clinician before use, especially at doses above typical dietary supplement levels.
Monitoring
Before starting
- Consider whether you are already getting enough zinc from diet or other supplements, to avoid unintentionally exceeding recommended intake.
During treatment
- Watch for stomach upset; take with food if needed.
- If using a high dose or for a prolonged period, watch for symptoms of copper deficiency (unusual tiredness, increased infections, numbness/tingling/weakness) and seek blood tests if they occur.
- Never use any zinc sulfate product in the nose.
Storage
Store oral zinc sulfate tablets/capsules at room temperature (approximately 15-30°C / 59-86°F), away from moisture, out of reach of children.
Professional information
Clinician-facing summary. Always consult current local product information, since exact strengths and formulations vary by country and manufacturer.
United States
Indication: Dietary supplement for zinc deficiency (oral); parenteral-nutrition additive (injectable, pharmacy-compounded)
Dose summary: Oral: commonly 50 mg elemental zinc once daily (as 220 mg zinc sulfate) or 25 mg elemental zinc (110 mg zinc sulfate). Injectable additive: adults 3 mg/day (metabolically stable), paediatric 50-400 mcg/kg/day depending on age/weight; high doses (~10x recommended) over extended periods risk copper deficiency.
Renal context: Not specifically detailed for the oral supplement in the reviewed sources. (1) (2)
New Zealand
Indication: Zinc supplement (adults)
Dose summary: ZINCAPS: zinc sulfate monohydrate equivalent to 50 mg elemental zinc per capsule.
Renal context: Not specifically detailed in the reviewed source. (8)
United Kingdom / European Union
Indication: Food supplement (zinc as a permitted mineral ingredient)
Dose summary: Product-dependent; governed by food-supplement law rather than a single harmonised medicinal dosing schedule.
Renal context: Not applicable. (6)
Australia / Canada
Indication: Listed medicine / Natural Health Product (oral); registered prescription medicine (injectable)
Dose summary: Product-dependent per the specific AUST L-listed or NPN-licensed product label.
Frequently asked questions
Is zinc sulfate a prescription medicine or an over-the-counter supplement?
Both, depending on the form. The oral tablet/capsule you buy at a pharmacy or supermarket is an over-the-counter dietary supplement (or Natural Health Product/listed medicine, depending on the country) in every market reviewed. A separate, prescription-only injectable form exists for adding zinc to intravenous nutrition, and is never self-administered. (1) (2)
Can I use zinc sulfate as a nasal spray for a cold?
No. Zinc sulfate should never be used in the nose. Intranasal zinc exposure has a real, long-documented risk of causing sudden and sometimes permanent loss of the sense of smell — this was first reported for zinc sulfate nasal spray as far back as 1938, decades before similar concerns arose with other zinc nasal products. (4)
Can taking zinc sulfate for a long time cause any harm?
Yes — sustained, high-dose zinc intake (from zinc sulfate or any zinc product) can cause copper deficiency, which is often under-recognised and can eventually cause nerve damage (numbness, tingling, weakness, balance problems) as well as anaemia and a low white blood cell count. This is why zinc supplements are meant to be used at labelled doses for the short term unless a clinician advises otherwise. (5)
Is zinc sulfate used for anything besides oral supplementation?
Yes. Besides the oral supplement, zinc sulfate is used at a low concentration (0.25%) as an over-the-counter ophthalmic astringent in combination eye-redness-relief drops, and separately as a prescription-only injectable additive that pharmacy staff compound into intravenous nutrition. (3) (2)
References
- Zinc Sulfate tablets -- dietary supplement labelU.S. National Library of Medicine, DailyMed · United States · accessed 2026-07-31 · source 1
- Zinc Sulfate solution, pharmacy bulk package -- prescription injectable additive for parenteral nutritionU.S. National Library of Medicine, DailyMed · United States · accessed 2026-07-31 · source 2
- OTC Monograph M018: Ophthalmic Drug Products for OTC Human UseU.S. Food and Drug Administration · United States · dated 2022-04-04 · accessed 2026-07-31 · source 3
- Persistent anosmia following zinc sulfate nasal spraying (1938); reviewed in Alexander & Davidson, 'Intranasal Zinc and Anosmia: The Zinc-Induced Anosmia Syndrome', The Laryngoscope, 2006Journal of Pediatrics (historic case report, 1938) and subsequent otolaryngology literature review · international / clinical literature · accessed 2026-07-31 · source 4
- Iatrogenic copper deficiency: Risks and cautions with zinc prescribing (Duncan et al., 2023)British Journal of Clinical Pharmacology -- peer-reviewed clinical pharmacology review · international / clinical literature · accessed 2026-07-31 · source 5
- Zinc as a permitted vitamin/mineral ingredient in food supplements (Schedules I and II, 2019 EU Exit Regulations; Directive 2002/46/EC)UK Government (Great Britain food supplement regulations, retained EU law) and EU Directive 2002/46/EC · United Kingdom / European Union · accessed 2026-07-31 · source 6
- TGA-listed (AUST L) oral zinc sulfate supplement products (e.g. Zinc Plus, ARTG 347980) and Zinc Sulphate (Phebra) injectableTherapeutic Goods Administration · Australia · accessed 2026-07-31 · source 7
- ZINCAPS (zinc sulfate monohydrate) capsules -- New Zealand Data SheetNew Zealand Medicines and Medical Devices Safety Authority (Medsafe) · New Zealand · accessed 2026-07-31 · source 8
- Zinc sulfate / zinc sulfate monohydrate -- Natural Health Product ingredient classification (Schedule 1, item 7, mineral)Health Canada, Natural Health Products Directorate · Canada · accessed 2026-07-31 · source 9
Brand names by country
Single-ingredient zinc sulfate names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Zinc Sulfate (generic, oral tablets) (1)current otc supplement label · 110 mg (25 mg elemental zinc), 220 mg (50 mg elemental zinc) · Multiple generic manufacturers per current DailyMed listings
- Zinc Sulfate Injection (pharmacy bulk package) (2)current prescription label · 30 mg/10 mL, 25 mg/5 mL · See current DailyMed listing
United Kingdom
- Zinc sulfate (generic, food supplement) (6)current permitted supplement ingredient · product-dependent · Varies by manufacturer; food-supplement classification unless disease claims are made
Canada
Australia
New Zealand
- ZINCAPS (8)current registered product · 50 mg elemental zinc (as zinc sulfate monohydrate) · See current Medsafe data sheet
View brands in additional countries.
European Union
Zinc sulfate (generic, food supplement) (6)