Zinc gluconate

Tier 2 — promising · Zinc form · Cold duration · Immune

Zinc gluconate has the bulk of the common-cold-duration RCT evidence (as lozenges, 75+ mg daily during acute illness), where zinc ions released in the oropharynx inhibit rhinovirus replication. As a general oral supplement it is adequately absorbed though slightly less so than chelates. Intranasal zinc gluconate (Zicam-type products) has caused permanent anosmia and should be avoided entirely. Oral gluconate at typical daily doses is safe and well-tolerated.

Dose: 15–30 mg elemental/day (maintenance); 75–100 mg/day as lozenges for max 5 days (acute cold)