Will Valtrex protect me from developing genital herpes from a partner who has a cold sore?

Dear Reader,

Valacyclovir, commonly known by the brand name Valtrex®, is a medication that’s prescribed to help manage outbreaks caused by the herpes simplex virus (HSV). HSV can cause cold sores and genital herpes. It’s fantastic that you’ve found relief from cold sores with daily valacyclovir use. However, while the medication significantly reduces the likelihood of herpes outbreaks, it doesn’t completely eliminate the risk of transmitting herpes or acquiring an outbreak on a different part of your body. Although your daily dose lowers your chances of developing genital herpes, the risk isn’t zero, especially if you’re exposed to HSV directly, such as during oral sex from a partner with an active cold sore. After being exposed, it’s recommended that you monitor yourself for symptoms like genital sores and pain. You may also consider visiting a health care provider. Going forward, you might consider avoiding oral sex when your partner has visible cold sores to further minimize your risk.

What is valacyclovir?

Valacyclovir is an antiviral medication used to treat HSV infections. This includes cold sores, also known as oral herpes (caused by HSV-1), as well as genital herpes (typically caused by HSV-2, but sometimes caused by HSV-1). Valacyclovir interferes with the virus’s ability to multiply in your body, reducing the likelihood of experiencing outbreaks. Importantly, valacyclovir does not cure HSV infections; once infected, the virus (either HSV-1 or HSV-2) stays in the body permanently. However, valacyclovir can reduce people’s symptoms, often to the point where they never experience new herpes outbreaks.

Can you get genital herpes from oral sex while taking valacyclovir?  

Unfortunately, even if you’re taking valacyclovir to treat oral herpes outbreaks, it’s still possible for you to develop a genital herpes outbreak. This is because the HSV-1 infection you’re treating caused outbreaks on or around your mouth, not on or around your genitals. Unlike some other viruses, herpes outbreaks are usually limited to the place on your body where the virus was transmitted. In fact, some people can end up giving themselves outbreaks on new body parts—for example, by touching their genitals after touching their own cold sores. Therefore, even though the possible transmission to your genitals would be caused by the same virus, it would be in a different part of your body, making that body part vulnerable to an outbreak.

That being said, taking valacyclovir definitely reduces your risk of experiencing a genital herpes outbreak; it just doesn’t bring it down to zero. Since valacyclovir is prescribed to treat existing herpes outbreaks, not to prevent new ones, it’s difficult to predict the likelihood of a new genital herpes outbreak while taking the medication. Being vigilant about symptoms—such as sores, pain, or itching around the genitals and anus—is important after potential exposure. 

How does genital herpes affect people?

While herpes can be a pain in the butt (and elsewhere), the vast majority of people with genital herpes live happy, fulfilling lives. In fact, most people with HSV infections don’t know that they’re infected because they don’t experience outbreaks. Furthermore, genital herpes outbreaks caused by HSV-1 tend to recur less frequently and less severely than those caused by HSV-2. This means that even if you experience an outbreak once, it’s less likely to happen again with HSV-1 than with HSV-2. Taking valacyclovir also reduces the chance of repeated outbreaks.  

Genital herpes doesn’t typically affect a person’s ability to become pregnant. However, an important concern arises during childbirth. If you’re pregnant and experience a genital herpes outbreak close to your due date, there’s a risk the virus could pass to the baby, potentially causing life-threatening complications. To minimize this risk, health care providers may prescribe antiviral medications during pregnancy or perform a C-section if there’s an active outbreak at the time of delivery. 

How do you avoid spreading herpes? 

Although genital herpes is most contagious during outbreaks, it’s possible to transmit it to others even if you’re not experiencing symptoms. It’s important to have open and honest conversations with your sexual partner(s) about symptoms and risks. Consistent use of antiviral medications, like your trusty valacyclovir, combined with use of barrier methods (condoms and dental damns) and avoiding sexual contact during outbreaks can significantly reduce the likelihood of transmitting herpes to partners. However, it’s important to note that barrier methods may not always cover the regions where genital herpes outbreaks develop. Additionally, genital herpes infection slightly increases the risk of contracting other sexually transmitted infections (STIs), including HIV. This is because herpes sores make it easier for HIV to enter the body. 

Ultimately, your daily valacyclovir helps to manage your cold sores and reduce your overall herpes risk. However, since it doesn’t completely eliminate the possibility of contracting genital herpes through oral sex, it’s important to remain cautious. If you experience symptoms of a genital herpes outbreak, consider visiting a health care provider. They may adjust your valacyclovir dosage or discuss other treatment options. 

Best of luck,