Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate)

Mineral supplements. Trace elements

ATC code: A12CB-ZINC(Zinc (oral salts, generic group))

Brand names – drugs: Galzin, Wilzin

Brand names – supplements: Jarrow Formulas Zinc Balance, Cold-Eeze, Thorne Zinc PicolinateSupplements are not tested in clinical trials and are not registered as medications.

Updated 24 Sep 2026 · Methodology

Indications

Wilson disease maintenance therapy

First line

Zinc acetate (Wilzin, Galzin) or zinc sulphate is maintenance therapy for Wilson disease after the initial copper chelation phase. Dose: 50 mg elemental zinc three times daily. Included in 2012 and 2023 guidelines as maintenance therapy. In asymptomatic ATP7B mutation carriers, it is first-line therapy. The effect develops over 4–8 weeks and requires lifelong use.

Used in specialised hepatology centres; not for self-prescription.

Sources

ICD-10: E83.0 · ICD-11: 5C64.00

Zinc deficiency

First line

Oral zinc is first-line for confirmed zinc deficiency. Adult doses are 25–50 mg elemental zinc daily for 1–3 months with plasma zinc monitoring. In children with diarrhoea in developing countries, recommends 10–20 mg zinc daily for 10–14 days – this approach reduces diarrhoea duration and recurrence. After bariatric surgery, in cystic fibrosis, Crohn disease, or parenteral nutrition, lifelong deficiency correction is required.

Sources

ICD-10: E60 · ICD-11: 5B5K.2

Common cold

Individual decision

Evidence is mixed. The 2013 Cochrane review (Singh & Das, 18 RCTs, around 2,000 participants) in adults found a 1–1.5 day reduction in cold duration with zinc lozenges or syrup at 75 mg elemental zinc daily, started within 24 hours of symptom onset. Zinc as **prevention** (continuous intake to avoid new URI episodes) has not reproduced its effect in large RCTs. The does not recommend zinc for colds in children – the modest clinical benefit does not justify side effects: nausea, unpleasant taste, diarrhoea. CDC and do not include zinc in URI management standards. Intranasal zinc has been withdrawn due to irreversible smell loss.

Efficacy critically depends on zinc form (lozenges or syrup, not tablets), dose, and timing. Starting later than 24 hours from symptom onset gives minimal effect. International societies do not support use in children.

Sources

Cochrane: Zinc for the common cold (2013)

ICD-10: J00 · ICD-11: CA00

Marketing claims without evidence base

The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.

Acne vulgaris (adjunctive therapy)

Not recommended

The 2020 Cochrane review rated the effect of oral zinc on acne as limited in evidence volume and quality. Weak positive results for inflammatory acne in small RCTs. International dermatology guidelines (, EAD) do not include zinc as first-line therapy. Topical zinc combined with erythromycin has a separate evidence base.

Sources

Cochrane: Zinc for the treatment of acne vulgaris (2020)

ICD-10: L70.0 · ICD-11: ED80

Anti-aging and longevity

Not recommended

Zinc is a trace element required in small amounts (recommended daily allowance 8–11 mg for adults). Zinc is found in red meat, seafood (especially oysters), legumes, and nuts. In anti-aging communities, zinc is sold to slow aging, prevent dementia, and extend life. In people without zinc deficiency, no clinical studies of prophylactic use for anti-aging exist; international guidelines do not include zinc as an anti-aging agent. Zinc overdose (above 40 mg/day chronically) causes copper deficiency with reduced immunity, anemia, and neurological symptoms; it can also reduce absorption of antibiotics (tetracyclines, fluoroquinolones). If zinc is being taken in high doses for longevity, consider seeking a second opinion.

Sources

How to read tiers A–F

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit

Mechanism of action

Zinc is a structural and catalytic cofactor for more than 300 enzymes, including carbonic anhydrase, alcohol dehydrogenase, and DNA polymerases. A structural component of zinc-finger transcription factors. Required for immune function, wound healing, thyroid hormone synthesis, and male reproductive function. In Wilson disease, zinc blocks intestinal copper absorption by inducing metallothionein in enterocytes.

Safety

Contraindications

Hypersensitivity to components
Severe renal impairment (for parenteral administration)

Serious adverse effects

Copper deficiency with microcytic anaemia, neutropenia, and myelopathy with long-term doses above 50 mg daily
Anosmia (irreversible) with intranasal zinc forms – the reason intranasal preparations have been withdrawn

Common adverse effects

Nausea, vomiting
Epigastric discomfort
Metallic taste
Diarrhoea at doses above 50 mg daily

Uncommon adverse effects

Reduced copper absorption with long-term high doses
Skin rash

Pregnancy: can you take Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate)?

Safe at physiological doses (RDA 11 mg daily). High doses (above 40 mg daily) in pregnancy are not recommended. Supplementation at the RDA is justified in pregnant vegetarians.

Breastfeeding: can you take Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate)?

Transfers into breast milk at physiological amounts. Supplementation at the RDA is safe.

Calculate RID

Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.

Practical notes

Timing and administration

Take 1 hour before or 2 hours after meals for maximum absorption. With dyspepsia, with-meal use is allowed, accepting a 30–40% drop in bioavailability. Picolinate, citrate, and bisglycinate salts are absorbed better than oxide and sulphate.

Dose titration

Adult RDA: 8 mg for women, 11 mg for men. Prophylactic supplement dose: 15 mg daily. Mild deficiency treatment: 25 mg daily for 4–8 weeks. Severe deficiency and Wilson: 50 mg three times daily. Upper tolerable intake level (UL): 40 mg daily for long-term use. Doses above 50 mg daily may induce copper deficiency over months.

Monitoring

With long-term high-dose therapy, monitor plasma zinc and copper every 6 months. Copper deficiency presents with anaemia, neutropenia, and myelopathy – particularly dangerous with uncontrolled high-dose zinc for more than 6 months.

Food and drinks

Dietary sources: oysters (highest), red meat, pumpkin seeds, nuts, whole grains, legumes. Zinc from animal sources is more bioavailable than from plant sources – phytates in whole grains and legumes reduce absorption. Vegetarians and vegans are advised to aim for 50% above the RDA.

Common myths

Myth: “zinc significantly shortens colds”. Fact: the effect is a 1–1.5 day reduction in symptom duration, requires starting within 24 hours at high doses with side effects (nausea, diarrhoea, taste loss). Does not prevent colds.

Myth: “zinc treats acne”. Fact: evidence is limited and the effect weak. Not first-line therapy. In resistant acne, isotretinoin and systemic antibiotics are considered, not zinc.

Myth: “zinc is safe at any dose”. Fact: doses above 50 mg daily long-term cause copper deficiency with anaemia, neutropenia, and myelopathy. Intranasal zinc causes irreversible anosmia and has been withdrawn.

Drug–nutrient interactions

Copper

Long-term zinc intake above 50 mg daily induces metallothionein synthesis in enterocytes, which binds copper and blocks its absorption. Copper deficiency develops with anaemia, neutropenia, and myelopathy. With long-term zinc therapy, monitor copper and ceruloplasmin every 6 months or supplement copper 1–2 mg daily.

Drug–drug interactions

6 pairs found. Sorted from critical to minor.

MajorCopperTrace cofactor mineral, used in parenteral nutrition and supplements

Mechanism

Zinc induces metallothionein in the enterocyte, and that protein traps copper and returns it to the gut lumen with the shed cell. NIH ODS puts numbers on it: doses of 50 mg of zinc or more over weeks inhibit copper absorption, reduce immune function and lower cholesterol. The resulting copper deficiency is one of the few supplement interactions with documented neurological harm.

Symptoms

Anaemia unresponsive to iron, neutropenia, and in advanced cases myelopathy: tingling and weakness in the legs, unsteady gait, impaired deep sensation. The neurological picture may not fully reverse once copper is corrected.

Management

Sustained high-dose zinc without oversight is the problem, not zinc itself. Above 40 mg daily long term, monitor the blood count and serum copper. -type ophthalmic formulas already include copper for this reason, and that is the sensible reference: long-term zinc comes with copper.

Sources

NIH Office of Dietary Supplements: Zinc – Health Professional Fact Sheet (2025)

Pair details →Copper →

ModerateCalcium (oral salts: carbonate, citrate, lactate, gluconate)Mineral supplements. Calcium

Mechanism

Calcium at supplement doses reduces zinc absorption, especially when dietary zinc is already low and when both land in the same dose. The effect grows with phytate from wholegrains and pulses, which binds zinc on its own account.

Symptoms

Signs of mild zinc deficiency: dulled taste, brittle nails, dermatitis in skin folds. Without labs these are indistinguishable from other causes.

Management

Take them at different times of day. On a vegetarian diet, where phytate already limits zinc, the separation matters more. An ordinary multivitamin with moderate amounts of both does not pose the same problem as two high-dose supplements at once.

Sources

Pair details →Calcium (oral salts: carbonate, citrate, lactate, gluconate) →

ModerateCiprofloxacinFluoroquinolone antibacterials

Mechanism

NIH ODS lists quinolone antibiotics among the drugs zinc interacts with, through the same chelation mechanism as the other divalent cations. The described magnitude is smaller than with calcium or iron, though the direction is the same both ways: the quinolone drops and so does zinc.

Symptoms

No symptoms of its own. It shows as reduced antibiotic efficacy over longer courses.

Management

During the course, keep zinc away from the antibiotic on the same basis as the other minerals. For week-long courses many patients prefer to pause zinc and resume afterwards, which is reasonable unless there is a specific indication.

Sources

Pair details →Ciprofloxacin →

ModerateDoxycyclineTetracyclines

Mechanism

NIH ODS names tetracycline antibiotics among those that interact with zinc. The binding reduces absorption of both. The combination is routine in dermatology: zinc is taken for acne and doxycycline is prescribed for the same thing.

Symptoms

Acne treatment that stalls despite good adherence.

Management

Spacing by 2–3 hours is enough. In dermatology practice zinc goes with dinner and doxycycline with breakfast or lunch.

Sources

Pair details →Doxycycline →

ModerateIron oral (salts: sulfate, bisglycinate, fumarate, gluconate, polymaltose; heme iron polypeptide, lactoferrin)Oral iron preparations; antianaemic agents

Mechanism

Iron and zinc share the DMT1 transporter at the enterocyte brush border. Taken together on an empty stomach at supplement doses, iron, usually present in far larger amounts, displaces zinc. With food in between, the competition dilutes because other ligands come into play.

Symptoms

On the zinc side: altered taste, slow wound healing, more minor respiratory infections. These are rarely attributed to capsule timing.

Management

Two hours apart resolves most of it. If iron treatment is long-term and zinc is also prescribed, place them at opposite ends of the day. With meals both are better tolerated, at the cost of slightly less iron absorption.

Sources

Pair details →Iron oral (salts: sulfate, bisglycinate, fumarate, gluconate, polymaltose; heme iron polypeptide, lactoferrin) →

MinorMetforminBiguanides. Oral antihyperglycemic agents

Mechanism

Zinc theoretically competes with metformin for renal tubular organic cation secretion, but no clinically significant hyperglycaemia has been described on the combination.

Symptoms

The combination usually causes no specific symptoms. Each drug's individual side effects remain.

Management

No dose adjustment needed. In diabetics with zinc deficiency (e.g. on a vegan diet), zinc supplements 15–25 mg/day are safe. Monitor on the usual schedule.

Sources

FDA: Metformin hydrochloride tablet (Sciegen Pharmaceuticals Inc) – Prescribing Information (2017)

Pair details →Metformin →

Check interaction with another drug

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Summary of a multi-drug list →

Medicine list: everything you take in one place →

Frequently asked

What is Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate) used for?

Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate) is evaluated for the following indications with varying evidence strength: Zinc deficiency (evidence tier A), Wilson disease maintenance therapy (evidence tier A), Common cold (evidence tier C). See the full indication matrix with dosing and citations above on this page.

What are the side effects of Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate)?

Common side effects of Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate) (≥ 1 in 100): Nausea, vomiting, Epigastric discomfort, Metallic taste, Diarrhoea at doses above 50 mg daily. See the Safety section for uncommon and serious reactions.

Is Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate) safe during pregnancy?

Safe at physiological doses (RDA 11 mg daily). High doses (above 40 mg daily) in pregnancy are not recommended. Supplementation at the RDA is justified in pregnant vegetarians.

Is Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate) compatible with breastfeeding?

Transfers into breast milk at physiological amounts. Supplementation at the RDA is safe.

Who should not take Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate)?

Zinc (oral salts: picolinate, citrate, gluconate, oxide, acetate) is contraindicated in: Hypersensitivity to components; Severe renal impairment (for parenteral administration). Full list in the Safety section.

“zinc significantly shortens colds”

the effect is a 1–1.5 day reduction in symptom duration, requires starting within 24 hours at high doses with side effects (nausea, diarrhoea, taste loss). Does not prevent colds.

“zinc treats acne”

evidence is limited and the effect weak. Not first-line therapy. In resistant acne, isotretinoin and systemic antibiotics are considered, not zinc.

“zinc is safe at any dose”

doses above 50 mg daily long-term cause copper deficiency with anaemia, neutropenia, and myelopathy. Intranasal zinc causes irreversible anosmia and has been withdrawn.

Official sources

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GRLS

Other drugs in this group

Boron, Calcium (oral salts: carbonate, citrate, lactate, gluconate), Calcium carbonate, Calcium + Cholecalciferol, Chromium picolinate, Magnesium L-threonate (Magtein), Molybdenum, Calcium D-glucarate