Protocols › Zinc

Zinc for blood sugar

Goal: What trials of zinc used to lower blood sugar, and how much it changed.

Each protocol describes what studies used, for one goal or for one group of people. It is not advice for you: talk to a doctor before you start a supplement.

Updated 10 Nov 2026
Dose

4 to 240 mg of zinc a day, 35 mg on average, in the trials of a 2019 review.[1]

Form

The fall in fasting glucose was larger with inorganic zinc compounds.[2]

How long

1 to 12 months.[1]

What studies found

In 32 trials with 1,700 people, fasting glucose fell by about 14 mg/dL and HbA1c by 0.55 percentage points compared with placebo.[2] The results did not differ between doses under 30 mg and 30 mg or more.[1]

Ask a doctor first

The NIH Office of Dietary Supplements says the evidence is not enough to draw conclusions about zinc for type 2 diabetes.[1] Doses above 40 mg a day are over the US upper limit for adults.[1]

People who take medicines every day should discuss zinc with their doctor or pharmacist.[1]

References

  1. Zinc: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  2. Zinc supplementation improves glycemic control for diabetes prevention and management: a systematic review and meta-analysis of randomized controlled trials. Wang X, Wu W, Zheng W, Fang X, Chen L, Rink L, et al. Am J Clin Nutr, 2019. PMID 31161192