Can taking Valtrex for shingles affect my birth control?
Ask the doctor
Q. I took Valtrex for shingles and I am on birth control. Does this make the birth control less effective?
A. No, the antiviral drug Valtrex (valacyclovir) should not make birth control less effective.
Valtrex treats herpes virus infections, such as herpes zoster (shingles) and genital herpes simplex. I could not find any reports of drug interactions with hormone-based medications used for birth control. This includes oral contraceptives, the patch, the ring, skin implants, or injections.
In fact, Valtrex has very few potential drug-drug interactions.
Perhaps you have raised this question because of an older concern that oral antibiotics might decrease the effectiveness of birth control pills and increase the risk of unwanted pregnancy. More recent studies do not support this conclusion. If a woman takes her birth control pills as prescribed, taking an antibiotic such as ampicillin or tetracycline should not be a problem. However, just to be extra cautious, some doctors recommend backup birth control during that menstrual cycle. Since this is a short-term issue, condoms are usually the most convenient backup method.
Image: © Suriyawut Suriya/Getty Images
About the Author
Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing
Disclaimer:
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
