Does zinc lower blood pressure?

Barely, if at all. The only meta-analysis built on this exact question pooled 9 randomized trials in adults and found zinc supplements lowered systolic pressure by 1.49 mmHg against control, with an interval running from 0.13 to 2.85 mmHg. Diastolic pressure did not change. Two broader meta-analyses, of 20 and of 75 trials, found no significant effect on blood pressure at all. The one group where the drop looks larger is adults with type 2 diabetes, at 3.64 mmHg systolic across 22 trials.

Myth. Zinc is not a blood pressure treatment. The largest body of trials, 75 randomized trials rated with GRADE, found no noticeable effect on systolic or diastolic pressure, even though the same trials showed zinc lowering triglycerides, cholesterol and blood sugar.

How much lower blood pressure was with zinc than with control, in mmHg

Bars show the pooled drop and lines its 95% confidence interval. The diastolic interval crosses zero, so that row is no different from no effect. Two broader meta-analyses of 20 and 75 trials found no significant effect on either number and do not publish one to draw. Sources: cards ev-znbp-01, ev-znbp-02 and ev-znbp-05 below.

What the trials found

The 2020 dose-response meta-analysis of 9 trials is the strongest case for zinc, and it is a small one. The systolic drop of 1.49 mmHg has a lower bound of 0.13 mmHg, close to nothing. Diastolic pressure fell by 0.88 mmHg with an interval from minus 2.04 to plus 0.29, which did not reach significance. Higher doses and longer courses did not produce larger effects. The abstract does not say how many people took part, and the full text was not available to us.

The broader syntheses point the other way. A 2020 meta-analysis of 20 controlled trials, which also admitted quasi-randomized studies, found the effect on blood pressure was not statistically significant. A 2023 meta-analysis of 75 randomized trials, rated with GRADE, found no noticeable effect on systolic or diastolic pressure. Neither abstract gives a size for the blood pressure result, only that there was none to report.

Diabetes is the exception worth naming. In adults with type 2 diabetes, a 2024 GRADE-assessed meta-analysis of 22 placebo-controlled trials in 1442 people found systolic pressure 3.64 mmHg lower on zinc, with an interval from 0.52 to 6.77 mmHg. The abstract does not list diastolic pressure among the results that changed. Two single trials sit below that average. In 98 people newly diagnosed with high blood pressure and already on one drug, zinc supplements or a mineral-rich diet improved zinc status and blood sugar and left blood pressure where it was. In 40 men with type 2 diabetes and normal zinc levels, 240 mg of zinc a day for 3 months did not change aortic pressure or other measures of artery stiffness.

Unsettled. The observational picture is contradictory, which is why it cannot carry the question. A 2019 meta-analysis of 25 mostly case-control studies found people with hypertension had lower serum zinc, with very high heterogeneity between studies. A 2026 meta-analysis of 16 observational studies found no consistent link. In a Chinese cohort of 12,177 adults followed for 6.1 years, hypertension risk fell with dietary zinc up to about 10.9 mg a day and rose above it. Part of the low zinc seen in hypertension may come from the treatment itself, as the next section explains.

Who should be careful

The people most likely to ask this question are the people whose zinc is moved by their medicine. A systematic review of 8 trials found ACE inhibitors, angiotensin receptor blockers and thiazide diuretics can lower zinc levels in people with hypertension, though most of those studies were small and did not record zinc in the diet. The NIH Office of Dietary Supplements states that thiazide diuretics such as chlorthalidone and hydrochlorothiazide increase zinc loss in urine. If you take one of these, a zinc test is a question for your doctor, and a supplement is not a substitute for the blood pressure drug.

Not for everyone. More zinc is not better. The NIH upper limit for adults is 40 mg a day, and 50 mg or more for weeks can block copper absorption, weaken immune function and lower HDL cholesterol. The diabetes trial that found no vascular benefit used 240 mg a day, six times that limit. The office notes that reaching these amounts from food alone is unlikely.

What expert bodies say

The NIH Office of Dietary Supplements addresses zinc and blood pressure only through the drug interaction with thiazides and through the upper limit. We found no Cochrane review of zinc for blood pressure, and no American or European heart society position that mentions zinc.

How we searched

Searched: a local copy of the PubMed baseline across all study types, for zinc with blood pressure, hypertension, systolic or diastolic (429 records), and for zinc with hypertension and cohort or dietary intake (178 records). We also searched the NIH zinc fact sheet, a local index of ClinicalTrials.gov, and the web for meta-analyses newer than the corpus. Searches run on 7 October 2026.

Included: four meta-analyses of randomized trials, two randomized trials, two meta-analyses of observational studies, one cohort, one systematic review of drug effects on zinc, and two NIH fact sheet passages. None of the carded papers has been retracted.

Excluded: a 2026 meta-analysis of many trace metals that mentions zinc only in passing, a narrative review of zinc excess with no pooled data, a diet-only trial that overlaps an included one, and pregnancy trials, which belong to a separate question.

What we read: abstracts from the PubMed baseline, and the relevant sections of the NIH fact sheet.

What we could not get: the full texts of the three main meta-analyses, so participant numbers and doses per trial for blood pressure are missing. No trial of zinc and blood pressure turned up in the ClinicalTrials.gov index.

What would change this answer

A properly powered randomized trial with blood pressure as its main outcome, in adults who are short of zinc. None of the pooled trials was built for that.
A trial in people taking thiazides or ACE inhibitors, the group whose zinc is lowered by treatment. One such trial is registered in Iran, and we found no results.
Full-text data on dose and starting zinc status from the existing meta-analyses, which would show whether the small systolic effect sits in deficient people only.

The rest of the nutrient, in one place. Zinc: the cold remedy that partly works, and the supplement that backfires → What it does, how much you need, who runs short, and what too much does, with the evidence level shown on every line.

The full guide

Zinc: the cold remedy that partly works, and the supplement that backfires

The same question for other foods (blood pressure)

Sources

ev-znbp-01 · Meta-analysis or systematic review · systematic review and dose-response meta-analysis of randomized controlled trials · n = 9 trials
Zinc supplementation significantly reduced SBP compared to the control [weighted mean differences (WMD) - 1.49 mmHg; 95% CI - 2.85 to - 0.13; P = 0.03].
Who: adults in randomized clinical trials of oral zinc supplementation reporting systolic or diastolic blood pressure
Effect: SBP WMD -1.49 mmHg (95% CI -2.85 to -0.13; P = 0.03)
Certainty: The only MA specifically on blood pressure. The effect is small (1.5 mmHg), the lower CI bound is near zero. No full text in PMC; the number of participants is not given in the abstract.
Eur J Nutr, 2020 · checked 2026-10-07 · we read the abstract
ev-znbp-02 · Meta-analysis or systematic review · systematic review and dose-response meta-analysis of randomized controlled trials · n = 9 trials
However, zinc supplementation had no significant effects on DBP (WMD - 0.88 mmHg; 95% CI - 2.04 to 0.29; P = 0.14).
Who: adults in randomized clinical trials of oral zinc supplementation
Effect: DBP WMD -0.88 mmHg (95% CI -2.04 to 0.29; P = 0.14); nonlinear analysis showed no dose or duration effect
Certainty: A larger dose does not give a larger effect: an argument against "one more pill will help".
Eur J Nutr, 2020 · checked 2026-10-07 · we read the abstract
ev-znbp-03 · Meta-analysis or systematic review · GRADE-assessed systematic review and dose-response meta-analysis of randomized clinical trials · n = 75 studies
The pooled findings indicated the significant lowering effects of zinc supplementation on triglycerides (TG), total cholesterol (TC), fasting blood glucose (FBG), Hemoglobin A1C (HbA1C), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), C-reactive protein (CRP), interleukin-6 (IL-6), Tumor necrosis factor-α (TNF-α), nitric oxide (NO), malondialdehyde (MDA), total antioxidant capacity (TAC), and glutathione (GSH), with no noticeable effects on low-density lipoprotein (LDL), high-density lipoprotein (HDL), insulin, systolic blood pressure (SBP), diastolic blood pressure (DBP), aspartate transaminase (AST), and Alanine aminotransferase (ALT).
Who: participants in randomized clinical trials of zinc supplementation and cardiovascular risk factors
Effect: no significant pooled effect on SBP or DBP; significant reductions in TG, TC, FBG, HbA1c, CRP
Certainty: The widest synthesis of RCTs (to January 2023). Numbers for blood pressure are not given in the abstract, only "no appreciable effect".
J Trace Elem Med Biol, 2023 · checked 2026-10-07 · we read the abstract
ev-znbp-04 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials (with quasi-RCTs) · n = 20 studies
The effects of zinc supplementation on blood pressure and anthropometric indices were not statistically significant (P > 0.05).
Who: participants in RCTs, quasi-RCTs and controlled clinical trials of zinc and cardiometabolic risk factors
Effect: blood pressure P > 0.05; lipids and glucose improved
Certainty: Quasi-RCTs also included; for blood pressure only P > 0.05 without a magnitude.
Biol Trace Elem Res, 2020 · checked 2026-10-07 · we read the abstract
ev-znbp-05 · Meta-analysis or systematic review · GRADE-assessed dose-response meta-analysis of randomized controlled trials · n = 22 studies, 1442 participants
Systolic blood pressure (SBP) (MD): -3.64 mmHg; 95% CI: -6.77∼ -0.52), weight (MD: 1.00 kg; 95% CI: 0.34∼1.66), CRP (MD: -3.37 mg/l, 95% CI: -4.05∼ -2.70), and serum zinc (MD: 15.38 µg/dl; 95% CI: 10.74∼ 20.02) changed to a statistically significant extent with zinc supplementation.
Who: adults with type 2 diabetes in placebo-controlled RCTs of zinc alone (no co-supplementation, no children or pregnant women)
Effect: SBP MD -3.64 mmHg (95% CI -6.77 to -0.52); nonlinear dose-response for SBP; certainty moderate to high overall
Certainty: Subgroup where the effect is larger: type 2 diabetes (zinc deficiency more common). Diastolic pressure is not named among the significant ones in the abstract.
Crit Rev Food Sci Nutr, 2024 · checked 2026-10-07 · we read the abstract
ev-znbp-06 · Randomized controlled trial(s) · randomized controlled trial · n = 98
Antihypertensive monotherapy combined with increased zinc supply in the diet or supplementation favorably modify zinc homeostasis and regulate glucose status without blood pressure affecting in patients with hypertension.
Who: newly diagnosed hypertensive patients on antihypertensive monotherapy, randomized to optimal-mineral diet, zinc supplementation or no change
Effect: zinc status improved; serum glucose decreased; blood pressure not affected
Certainty: Small RCT; blood pressure is not the primary outcome. Zinc dose not stated in the abstract, no full text.
J Trace Elem Med Biol, 2018 · checked 2026-10-07 · we read the abstract
ev-znbp-07 · Randomized controlled trial(s) · randomized placebo-controlled trial · n = 40
Forty male type 2 diabetic patients were supplemented either with 240 mg/day of zinc as zinc gluconate (n=20) or with placebo (n=20) for 3 months.
Who: male patients with type 2 diabetes and normal zinc levels
Effect: augmentation index, pulse wave velocity and aortic pressure unchanged vs placebo despite higher serum zinc
Certainty: The dose of 240 mg/day is six times higher than the UL of 40 mg. Without deficiency there is no benefit even at a very high dose.
Atherosclerosis, 2011 · checked 2026-10-07 · we read the abstract
ev-znbp-08 · Observational data · meta-analysis of observational (mostly case-control) studies · n = 25 articles
25 articles of serum Zn and 22 articles of serum Cu were included in meta-analysis.
Who: hypertensive patients versus controls in observational studies
Effect: serum zinc SMD -0.612 (95% CI -0.951 to -0.274); I2 = 97.0%
Certainty: Association, not cause: blood pressure drugs themselves lower zinc (ev-znbp-11). I² 97%: the data are highly heterogeneous.
J Trace Elem Med Biol, 2019 · checked 2026-10-07 · we read the abstract
ev-znbp-09 · Observational data · systematic review and meta-analysis of observational studies · n = 16 studies
No consistent associations were observed for Zn, Fe, Mg, or Se.
Who: hypertensive and normotensive adults in observational studies published 1970 to 2025
Effect: no consistent association for Zn; no difference in Zn/Cu ratio
Certainty: Newer than ev-znbp-08 and contradicts it: even the association is unstable.
Environ Sci Pollut Res Int, 2026 · checked 2026-10-07 · we read the abstract
ev-znbp-10 · Observational data · prospective cohort study · n = 12,177
The risk of new-onset hypertension significantly decreased with the increment of dietary zinc intake (per mg/day: hazard ratio (HR) 0.93; 95% confidence interval (CI) 0.88-0.98) in participants with zinc intake < 10.9 mg/day, and increased with the increment of zinc intake (per mg/day: HR 1.14; 95% CI 1.11-1.16) in participants with zinc intake ≽ 10.9 mg/day.
Who: Chinese adults free of hypertension at baseline, China Health and Nutrition Survey
Effect: per mg/day: HR 0.93 (95% CI 0.88 to 0.98) below 10.9 mg/day; HR 1.14 (95% CI 1.11 to 1.16) at 10.9 mg/day or above
Certainty: A single cohort, dietary zinc from 24-hour surveys; residual confounding is possible (meat, salt). The J-shape is an argument that "more" is not better.
Front Med, 2023 · checked 2026-10-07 · we read the abstract
ev-znbp-11 · Observational data · systematic review of clinical trials (no pooling) · n = 8 studies
The available evidence suggests that use of ACE inhibitors and angiotensin 2 receptor antagonists or thiazide diuretics have the potential to reduce zinc levels in hypertensive patients.
Who: hypertensive patients in clinical trials of antihypertensive medicines reporting zinc measures
Effect: increased urinary zinc loss with captopril, enalapril, losartan, hydrochlorothiazide; lower serum zinc with captopril, verapamil, atenolol, losartan plus HCTZ
Certainty: Interaction in the reverse direction: blood pressure drugs → less zinc. Most studies are small, without accounting for dietary zinc.
Int J Clin Pract, 2013 · checked 2026-10-07 · we read the abstract
ev-znbp-12 · Position of an expert body · agency fact sheet · n = —
Thiazide diuretics, such as chlorthalidone (e.g., Hygroton, Thalitone) and hydrochlorothiazide (e.g., Esidrix, HydroDIURIL), increase zinc excretion in the urine.
Who: people taking thiazide diuretics
Effect: increased urinary zinc excretion; decreased serum zinc
Certainty: Who should be careful and who should check zinc: people on thiazides. Agency position without a number.
NIH Office of Dietary Supplements, Zinc fact sheet for health professionals · checked 2026-10-07 · we read the section
ev-znbp-13 · Position of an expert body · agency fact sheet · n = —
Doses of 50 mg of zinc or more over a period of weeks can inhibit copper absorption, reduce immune function, and lower high-density lipoprotein cholesterol levels; however, it is unlikely that a person would obtain this much zinc from food alone.
Who: healthy individuals (ULs do not apply to people treated with zinc under a physician)
Effect: UL 40 mg/day adults; 4 to 34 mg/day infants, children and adolescents; >=50 mg/day for weeks impairs copper absorption, immune function and HDL
Certainty: "Treating" blood pressure with zinc at doses above 40 mg is more dangerous than the benefit of 1.5 mmHg.
NIH Office of Dietary Supplements, Zinc fact sheet for health professionals · checked 2026-10-07 · we read the section

How this page was made. Evidence was extracted from primary sources into cards, every number was re-checked against the source, and the text was written from those cards. Bioma Learn has no human medical reviewer at this time, and we say so rather than invent one. Methodology. This is information, not medical advice.