Zinc and the common cold

Zinc supplements (frequently zinc acetate or zinc gluconate lozenges) are a group of dietary supplements that are commonly used in an attempt to treat the common cold.^[1] Evidence of any benefit is weak, but it seems zinc may not prevent colds, but possibly reduce their length while not reducing the severity of the symptoms.^[2] Adverse effects with zinc supplements by mouth include bad taste and nausea.^[1][3] The intranasal use of zinc-containing nasal sprays has been associated with the loss of the sense of smell;^[1] consequently, in June 2009, the United States Food and Drug Administration (USFDA) warned consumers to stop using intranasal zinc.^[1]

The human rhinovirus – the most common viral pathogen in humans – is the predominant cause of the common cold.^[4] The hypothesized mechanism of action by which zinc reduces the severity and/or duration of cold symptoms is the suppression of nasal inflammation and the direct inhibition of rhinoviral receptor binding and rhinoviral replication in the nasal mucosa.^[1]