How long does it take for syphilis 1:1 to turn negative needs to be analyzed on a case-by-case basis and cannot be generalized. Syphilis 1:1 can be seen in the following cases: 1. If the syphilis infection is recent, 3 courses of routine syphilis repellent treatment are required. In the absence of penicillin allergy, long-acting penicillin gluteal intramuscular injection treatment, once a week for 3 weeks. After stopping the drug, the titer should be rechecked every 3 months in the first year, every 6 months in the second year, and at the end of the third year, the titer can gradually turn negative under normal circumstances (no combined HIV infection, neurosyphilis, etc.). 2. In the case of neurosyphilis excluded, it is called “serum fixation” and can be followed up for a long time without special treatment. It is recommended that patients visit the dermatology department of a regular hospital and actively cooperate with the treatment under the guidance of a professional doctor.