Written by Kianna DuFault, MPH, and Morgan Michalkiewicz, MPH

Penicillin is a commonly used antibiotic. It plays a critical role in treating bacterial infections, including syphilis.^1,2 A specific form of penicillin called Bicillin L-A (penicillin G benzathine) is recommended as the first-line treatment for syphilis and as treatment during pregnancy to help prevent congenital syphilis. Congenital syphilis occurs when untreated syphilis in a pregnant woman spreads to her baby during pregnancy or birth.¹

Currently, the United States is experiencing a shortage of Bicillin L-A. To help address this, the Centers for Disease Control and Prevention (CDC) and U.S. Food and Drug Administration (FDA) are working to manage the supply, including allowing temporary importation of an alternative product named Lentocilin.³

Because supply is limited, available Bicillin L-A is being prioritized for pregnant patients. Other effective treatments may be used for nonpregnant individuals when appropriate.³

Why This Matters

Syphilis cases continue to rise across the United States.⁴ Syphilis is a sexually transmitted infection (STI) that can cause serious health problems if left untreated, including complications affecting the brain, heart, and other organs. It can also be passed from a pregnant person to their baby, leading to congenital syphilis.⁵

What You Need to Know

Treatment for syphilis is available. However, the shortage may affect how and when Bicillin L-A is used to treat syphilis. In some areas, health care providers may rely more on alternative treatments for nonpregnant patients, when appropriate.

What You Can Do to Prevent Syphilis

• The best ways to prevent syphilis are to either:
  • not have sexual contact
  • only have sexual contact with someone who is not infected and who only has sexual contact with you.⁶
• Get tested before having sexual contact if you or your partner:
  • regularly have sexual contact with more than one partner
  • may have syphilis or another sexually transmitted infection (STI)
  • have syphilis symptoms
  • are pregnant or plan to become pregnant. (This will lower the chance that an infection is spread to the baby.)⁶
• If you or your partner may have syphilis, use a condom when having sexual contact (from start to finish). Condoms can reduce the risk of spreading syphilis. However, condoms must be used exactly right every time and may not cover all syphilis sores.⁶

Rising syphilis rates underscore the importance of STI prevention, timely STI screening, and early STI treatment to reduce transmission and protect maternal and infant health. To request 
an at-home STI test kit, please complete this form. 

Learn More

View GLITEC’s syphilis factsheet to learn more about syphilis, including its symptoms, how it spreads, and the steps you can take to protect both yourself and your community.

For updates and additional details about the Bicillin L-A shortage, visit the Centers for Disease Control and Prevention website.

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Sources 
1.    Syphilis. Centers for Disease Control and Prevention. October 3, 2024. Accessed April 16, 2026. https://www.cdc.gov/std/treatment-guidelines/syphilis.htm

2.    Saikia S, Chetia P. Antibiotics: from mechanism of action to resistance and beyond. Indian J Microbiol. 2024;64(3):821-845. doi:10.1007/s12088-024-01285-8

3.    Bicillin® L-A shortage. Centers for Disease Control and Prevention. March 10, 2026. Accessed April 16, 2026. https://www.cdc.gov/nchhstp/director-letters/bicillin-update.html

4.    Fatima Z, Ahmad B, Abdullah M, Suheb MK, Naaz F, Akilimali A. Unraveling the resurgence of syphilis: a deep dive into the epidemic sweeping across the United States; a mini review. 
Ann Med Surg (Lond). 2025;87(2):641-649.doi:10.1097/MS9.0000000000002916

5.    About congenital syphilis. Centers for Disease Control and Prevention. January 31, 2025. Accessed April 16, 2026. https://www.cdc.gov/syphilis/about/about-congenital-syphilis.html

6.    About syphilis. Centers for Disease Control and Prevention. January 30, 2025. Accessed April 16, 2026. https://www.cdc.gov/syphilis/about/index.html