DEAR DOCTOR: Are cold sores and herpes the same thing? I've got both, and finding out there's no cure really stinks. My friends say lysine can help. Is that true?
DEAR READER: Cold sores and genital herpes are caused by different types of the herpes simplex virus, or HSV. Each type is quite contagious.
HSV-1 causes cold sores on the lips and mouth. It's estimated that half of the population in the United States is infected with the oral herpes virus. The majority of genital herpes, which is a sexually transmitted disease, is caused by HSV-2. The infection rate of HSV-2 in the U.S. is estimated to be at least 15 percent and as high as 20 percent. Some cases of genital herpes are caused by HSV-1, as the virus can be spread from the mouth to the genitals.
You're correct that at this time, there is no cure for either type of herpes infection. Instead, people who have frequent outbreaks seek to manage the condition. Many people infected with HSV-2 rely on antiviral medications, which can shorten or suppress outbreaks of genital herpes and also lessen symptoms when an outbreak does occur. The three main drugs are acyclovir (Zovirax), famciclovir (Famvir), and valacyclovir (Valtrex). Antivirals may also be prescribed to people infected with HSV-1 who are having frequent or severe outbreaks. The over-the-counter cream Abreva, which targets oral herpes, can be useful at curbing an outbreak when used at the first sign of symptoms.
When it comes to lysine, there is both scientific and anecdotal evidence regarding its efficacy in diminishing the frequency of herpes outbreaks. The results of the earliest yes-it-works lysine studies, which date back to the 1970s and '80s, have been replicated in subsequent studies over the years. And the first time we wrote about HSV-2 in this column and didn't mention lysine, we got a flood of letters from readers with testimonials as to its usefulness. However, due to conflicting data regarding whether lysine will also decrease the severity or duration of an outbreak, that particular effect remains up for debate.
Lysine is what is known as an essential amino acid. Amino acids are the organic compounds from which proteins are made. Of the 20 amino acids we humans require, 11 are produced by our bodies. The remaining nine, known as essential amino acids, must be obtained through diet. Lysine is found in dairy products like milk, cheese and yogurt; meat; beans; brewer's yeast; and wheat germ. Supplements are also widely available. Although the mechanism by which lysine interferes with the herpes virus is not yet clear, researchers believe that it somehow short-circuits the reactivation functions of the virus.
Side effects can include stomach upset, abdominal pain, nausea and diarrhea. Lysine can increase how much calcium the body absorbs, so taking lysine along with calcium supplements requires caution. Although rare, lysine has been tied to reports of certain kidney problems. The safety of taking lysine while pregnant or breastfeeding is not known. If you decide to try lysine, please check with your family doctor for recommended dosages.
Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health.