I have syphyllis and my doctor put me on doxycline hcl 100mg. will this medication help me and will i start feeling funny?

The preferred treatment for all stages of syphilis is still penicillin. If you're allergic to penicillin, doxy is a good alternative. The proper dose for early syphilis is 100mgs twice a day for 14 days. I don't think you'll feel funny unless you're intolerant of doxycycline.

Doxycycline is one treatment option for syphilis. Common side effects include diarrhea and increased sensitivity to the sun, so it’d be advisable to limit exposure to the sun by covering the skin when outside and applying sunblock. Antacids (Tums, Pepto Bismol) and vitamins may also decrease the effectiveness of doxycycline and should be taken 1-2 hours before OR 4 hours after taking doxycycline.