Cold sores are tiny --- 1 to 2 mm --- fluid-filled blisters that develop on the lips and, occasionally, other parts of the face. Larger cold sores sometimes result, according to dermatologist Christina Cernik, M.D. in the June 9, 2008 issue of "Archives of Internal Medicine," when multiple small cold sores converge. Although prescription drugs can reduce the duration and severity of cold sores, they are expensive and usually reserved for people who have unusually severe or frequent outbreaks. Several forms of zinc have attracted attention as an alternative or complement to prescription drugs.
Forms
Zinc is a metal second only to iron in terms of its concentration within the body, according to MedlinePlus, a patient information service jointly maintained by the National Institutes of Health and the National Library of Medicine. Pure zinc is unstable because it carries a positive electrical charge, so it's usually found attached to other molecules that carry a negative electrical charge. Examples include zinc sulfate, oxide, zinc picolinate and zinc monoglycerolate. Some forms of zinc can be ingested orally, while others should only be applied to the surface of the skin.
Physical Effects
Zinc oxide is a form of zinc used in sunscreens. It physically deflects ultraviolet light away from skin. Since ultraviolet light from the sun can trigger cold sores, using sunscreens that contain zinc oxide helps prevent new outbreaks. However, zinc oxide is not the only compound that offers protection from ultraviolet light and there is no evidence that sunscreens that use zinc oxide are any more effective than other kinds of sunscreen.
Chemical Effects
Liquid solutions of zinc sulfate or zinc monoglycerolate and commercially available zinc-containing creams relieve cold sore itching, burning, stinging and pain in as little as 10 minutes after they are applied, according to holistic medicine specialist Alan R. Gaby, M.D. in the December 2005 issue of "Alternative Medicine Reviews." They also hasten healing. Gaby writes that in one study, patients who applied zinc sulfate-soaked bandages eight to 10 times per day experience healing in three to five days, compared to seven to 10 days for untreated patients.
Nutritional Effects
Zinc supports the health of the immune system, which plays a key role in fighting the herpes simplex virus that causes cold sores. In his 2007 book "Integrative Medicine," University of Wisconsin professor David Rakel, M.D. claims that taking 25 mg per day of oral zinc sulfate prevents cold sores in most people. When outbreaks do occur, Rakel says they usually resolve within one day. Higher doses should be avoided, however, because they interfere with the absorption of copper, iron and calcium.
Considerations
Patients can purchase zinc supplements at most drug and grocery stores. Zinc works best in conjunction with other health-promoting strategies such as managing stress, getting enough rest and exercise and consuming a balanced diet. Zinc does not replace conventional medical treatments for cold sores or any other condition. People who experience severe, frequent or prolonged outbreaks --- longer than two weeks --- outbreaks should see a doctor.
References
- MedlinePlus: Zinc in Foods
- "Archives of Internal Medicine"; "The Treatment of Herpes Simplex Infections; Christina Cernik, M.D., et al.; June 9, 2008
- "Integrative Medicine"; David Rakel, M.D.; 2007
- "Alternative Medicine Reviews"; Natural Remedies for Herpes Simplex; Alan R. Gaby, M.D. ; December 2005
