Whether you call them fever blisters or cold sores, more than 80 percent of American adults suffer from these painful bumps that cause discomfort in more ways than one. Unsightly and embarrassing, the lesions can inhibit the ability to eat and talk, often dealing a blow to self-esteem. Happily, you don’t have to throw in the towel the next time an outbreak hits: The amino acid lysine can help you triumph over cold sores and much more.
Since it cannot be produced in the body, L-lysine must be obtained from food or dietary supplements. It’s important for many biological functions, including synthesis of connective tissues—collagen, elastin, and skin—and bone. Because lysine helps improve calcium absorption, some scientists believe it may be a useful tool in preventing bone loss linked with osteoporosis. Lysine helps synthesize carnitine, which converts fatty acids to energy, and it also supports a healthy immune system. With antiviral properties best known for helping fight cold sores, lysine supplements can also speed recovery from shingles caused by Herpes zoster viruses.
What Are Cold Sores?
Cold sores are caused by the highly contagious Herpes simplex 1 virus (HSV-1), which is similar to (but not the same as) the one that causes genital herpes. Sores appear on the outer lips or on the palate inside the mouth. HSV-1 is spread by contact with saliva of an infected individual or fluid from a cold sore blister. Primary infection often occurs in childhood, and symptoms may be confused with teething or a flu-like illness involving fever. After the first exposure, HSV-1 lies dormant in the nervous system near the mouth until it is reactivated by a trigger (a cold, fever, food sensitivity, hormone fluctuations, infection, sunlight, or good old-fashioned stress).
The herpes virus depends on the amino acid arginine for replication, so avoid food sources of arginine, including dairy products, chocolate, coconut, meats, soybeans, white flour, walnuts, and wheat germ. Since the essential amino acid lysine displaces arginine in the virus, it may be useful in preventing and speeding recovery from herpes outbreaks. Look for supplemental lysine in tablets, capsules, and liquid extract, as well as in topical formulas.
A small 2005 study tested the effect of a topical cream containing lysine and other healing nutrients like calendula and vitamin E on cold sores. Within six days of using this topical treatment, 28 out of 30 patients noticed a significant improvement in itching, soreness, swelling, and number of blisters—and 40 percent of participants reported a complete cure.
Some experts recommend large doses of supplemental lysine during a Herpes simplex outbreak followed by a lower daily dosage to help prevent future eruptions. Although these supplements are considered nontoxic, with no reports of negative interactions with conventional medications, consult your healthcare provider before using if you have elevated cholesterol and/or triglyceride levels or cardiovascular disease.