Zinc for the Treatment of Herpes Simplex Labialis (HSL)
A Randomized, Double-blind, Placebo-controlled, Multi-Center Trial of Zinc for the Treatment of Herpes Simplex Labialis (HSL)
  • Phase

    Phase 3
  • Study Type

  • Intervention/Treatment

    zicam ...
  • Study Participants

Evaluate the effectiveness of a topical preparation of zinc to treat cold sores.
Zinc salts irreversibly inhibit herpes virus replication in vitro and are effective in treating herpes infections in vivo and have been shown in a clinical trial to be a effective topical treatment for HSL. Zinc salt solutions applied to herpetic lesions decrease viral load and markedly improve healing rates, relieving the symptoms of herpes as healing occurs. Zinc swabs contain 33 mmol/l of ionic Zinc in an emulsification of Benzalkonium chloride, glycerin, hydroxyethylcellulose, sodium chloride, and sodium hydroxide (ph 7.2). Zinc gluconate is monographed in the Homeopathic Pharmacopoeia of the United States (HPUS) and one of OTC indications for Zinc and its salts is for the treatment of cold sores.
Study Started
Dec 31
Primary Completion
Sep 30
Study Completion
Dec 31
Results Posted
Jan 08
Last Update
Jan 08

Drug Zicam (Ionic zinc)

33mmol/l of ionic zinc

  • Other names: Homeopathic Zinc gluconate

Drug placebo

placebo swab

  • Other names: placebo swab

Zinc gluconate Active Comparator

Oral swabs containing homeopathic Zinc gluconate

Placebo Placebo Comparator



Inclusion Criteria:

Subjects with a history of HSL with at least 2 episodes/year for the past two years that have proceeded beyond the prodromal (initial) stage
Male or female subjects between 18 and 65 years of age
Symptoms or signs of HSL for less than one day (max. 36 hours from onset of symptoms to first visit)
Confirmation of HSL by a clinician at the study site
Willing to comply with study instructions and sign an informed consent

Exclusion Criteria:

HSL symptoms or signs for more than one day
Cold sore outbreak within the past 2 weeks
Previous participation in this clinical trial
Topical or oral antiviral drug use in the past 1 week
Immune deficiency (HIV positive), chronic steroid therapy, present anti-neoplastic or radiation therapy, Hodgkin's disease, splenectomy, leukemia, myeloma, lymphoma, or another condition/drug per judgment of attending health care professional) or currently taking immune suppressive drugs. Previous organ or bone marrow transplant.
Pregnancy or lactation
Unable to travel to the clinic area for the required visits
Apparent inability to understand or follow the instructions associated with the clinical study
History of adverse events to the study material or facial cosmetics


Active Treatment

Placebo Treatment

All Events

Event Type Organ System Event Term

Zicam Was Compared to Placebo as a Treatment of Recurrent HSL From the Date and Time of the Initiation of Therapy Until the Date and Time of Resolution of the Lesion or After 14 Days of Treatment, Whichever Comes First.

Zinc gluconate swabs were compared as a treatment of recurrent HSL compared to placebo from the date and time of the initiation of therapy until the date and time of resolution of the lesion or after 14 days of treatment, whichever comes first.

Active Treatment

Days to resolution (Median)
95% Confidence Interval: 0.0 to 16.0

Placebo Treatment

Days to resolution (Median)
95% Confidence Interval: 0.0 to 21.0

Compare Zicam to Placebo on the Incidence of, Speed of, and the Rate of Healing for Aborted Cold Sore Lesions.

Outcome Measure Data Not Reported



Age, Continuous

years (Mean)
Standard Deviation: 12.0

Age, Categorical

Region of Enrollment

Sex: Female, Male

Overall Study

Active Treatment

Placebo Treatment