For many STD medications in Thailand, you may be tested in advance or show a prescription before receiving treatment (since they are antibiotics). But they should be generally available. For Trichomoniasis, Metronidazole, the medications should be available. For gonorrhea, the treatment is a bit more tricky, since gonorrhea in Asia (and specifically in Thailand) is resistant to many antibiotics. so you should go to the hospital to see how they can treat you. While treatment may vary, you may get Azithromycin or a a shot of a Cephalosporin. HPV vaccines, like Gardasil, are reportedly available in Thailand. PreP is available in Thailand, but is mostly used in trials with men who have sex with men (MSM), transgender (TG) women, women and people who inject drugs. Truvada is registered for treatment but not prevention. People with HIV/AIDS can bring their medications into Thailand, and there are no travel restrictions. Protease inhibitors only exist as original formula.