Syphilis is treated with parenteral penicillin. This means that the penicillin is either injected into the muscle or given intravenously. Oral penicillin has not been shown to be effective in treating syphilis.
The drug regimens below are taken from the the Centers for Disease Control 2006 STD treatment guidelines. Remember that only your doctor can say which treatment is right for you.
Recommended Regimen for Adults With Primary or Secondary Syphilis
Benzathine penicillin G 2.4 million units in a single intramuscular injection
Recommended Regimen for Adults with Early Latent Syphilis
Benzathine penicillin G 2.4 million units in a single intramuscular injection
Recommended Regimen for Adults with Late Latent Syphilis, Latent Syphilis of Unknown Duration, or Tertiary Syphilis
Benzathine penicillin G 7.2 million units total, administered as 3 intramuscular doses of 2.4 million units each at 1-week intervals
Recommended Regimen for Adults with Neurosyphilis or Syphilitic Eye Disease
Aqueous crystalline penicillin G 18-24 million units per day, administered as 3-4 million units IV every 4 hours or continuous infusion, for 10-14 days
Alternative Regimen for Adults with Neurosyphilis or Syphilitic Eye Disease
Procaine penicillin 2.4 million units IM once daily
PLUS
Probenecid 500 mg orally four times a day, both for 10–14 days
Notes: HIV+ individuals with syphilis may require additional treatments.
Pregnant women with syphilis are normally treated with the same regimen as other adults.
If you have been diagnosed with syphilis, your sexual partners need to be treated as well. Depending on the stage of your syphilis, at the time of diagnosis, the number of sexual partners who need to be notified will vary. If you were diagnosed with
- Primary Syphilis – All partners you have had for up to 90 days before you started experiencing symptoms should be tested and treated.
- Secondary Syphilis – All partners you have had for up to 6 months before you started experiencing symptoms should be tested and treated.
- Early Latent Syphilis – All partners you have had for up to 1 year before you started experiencing symptoms should be tested and treated.

