Thank for this opportunity as I’ve been reading similar posts for peace of mind but decided to ask my own question. On Wednesday evening I performed unprotected oral on a guy I met on a cruising site. According to him he had a gf and was clean with no issues. I am also a male. The oral session was only for a few minutes and he did not finish. I asked to stop because I freaked out. I’ve been having immense guilt and anxiety from the situation. 

I took 1 500mg of ampicillin 24 hours after the incident and then 200mg of Doxypep 46 hours after the encounter. 

1. Do you think I’m in any danger or any STD’s specifically syphilis? I’ve been googling nonstop and I’m really in a state of panic. 

2.How soon do you recommend I test for all of the STD’s? 

3. Can I have resume unprotected sex with my regular partner?

4. Does oral syphilis spread to other parts of the body (penis) if positive? 

5. Do you consider this a high risk encounter? 

You overreacted to a very low risk situation. Most people who believe they have no STD are right, and you describe a partner seemingly at little or no risk anyway (i.e. a usually monogamous guy who generally doesn't have sex with men). So your partner probably had no active infection. And even if he were infected, oral sex is inherently low risk for all STDs and zero risk for several of them. I would have advised against either doxyPEP or ampicillin (and ampicillin added absolute no protection over that from doxycycline). I'll also give our standard warning about online searching about health issues of concern. "Googling" implies you've looked lots of online resources, probably without regard to their reliability. You'll be far less likely to be misled if you stick with professionally run sites (like public health, academic medical resources, etc) or at least professionally moderated ones (like our forum). Sites run by and for people with a particular problem or at risk for it are especially problematical:  anybody can write anything they want and so much information is complete BS. Like Reddit, for example. To your numbered questions:

1. You were at little risk for any STD.

2. You don't need testing at all, especially having taken doxycycline. Of course reassurance alone is a valid reason for testing, so feel free to have a urine gonorrhea/chlamydia test 4-5 days after the event and blood tests for HIV and syphilis after 6 weeks. If somehow I were in your situation, I would not feel such a need (and would not have taken doxyPEP).

3. I see no reason to not have unprotected sex with your partner.

4. Yes, syphilis becomes a body-wide infection over the first few weeks. But you were at little if any risk for syphilis, and it was prevented by the doxycycline (and ampicillin).

5. No. It was a near zero risk encounter.

Having read other questions, you probably predicted these replies -- but I hope this reply is helpful. Let me know if anything isn't clear.

HHH, MD

Thank you for your response. It has helped to put my mind  at ease. I have to admit that I’m still worried but I do feel better overall. I went to an urgent care and believe it or not the refused to give me doxycycline. or any antibiotics because they said I had to symptoms and that it didn’t warrant for them to give me a prescription. I had to request a Telehealth service and they agreed to give me a dose of the doxycycline. 

I wanted to post here because like you said, google and Reddit shared some horror stories that didn’t make me feel good about the situation at all. I did have a few more questions.

1 . Do you recommend that I still take any more antibiotics? I have 3 more 500mg of ampicillin and I’m contemplating to finish them over the next few days as a back up.

2. Google says the doxycycline is about 70-80% effective and that reduces as the hours go by after an encounter. Being that I took it 46 hours after the incident do you think it was effective with that range or is googled under reporting the effectiveness?

3. Out of all STD’s I’m worried about after performing oral, it’s syphilis. You said that it was prevented now that I took the doxycycline. Would you say it was 99% prevented after taking the doxycycline? Can I bury this fear since I have taken the doxy about getting syphilis? 

4. Lastly, do you think it’s too early to be a full panel next week? Obviously like you said I’ll get the Gonorrhea and chlyamydia but will the other tests be valid? 

5. I know this question was asked but just to make sure I should have no

Issues having regular vaginal sex with my partner( she’s female) without putter her at risk for anything?

Thank you again. 

1. Good grief. What about my previous reply did you not understand? You should not have had any antibiotic at all and certainly should not have any more.

2. 70-80% effectiveness of doxyPEP was the finding of existing studies. However, there are several reasons to believe those figures underestimate the true effectiveness -- largely because many (even most) of the study subjects did not really understand when and where they were exposed. In those with known exposure to definite syphilis or chlamydia who took doxycycline within 72 hours, virtually nobody later turned out to be infected.

3. More like 100% effectiveness. And the chance your partner had transmissible syphilis is near zero, especially if you didn't see or feel an obvious penile sore that contacted your mouth.

4. Depends on what you mean by "full panel." Testing for gonorrhea and chlamydia will be valid about 7-10 days after the doxycycline. Syphilis testing needs to be delayed 4-6 weeks before being valid. (One downside of doxyPEP is delay in the time to conclusive testing.)

5. This answer hasn't changed. You were at no significant risk for any STD and therefore cannot have anything to pass to your partner.

1. You said “4. Depends on what you mean by "full panel." Testing for gonorrhea and chlamydia will be valid about 7-10 days after the doxycycline. Syphilis testing needs to be delayed 4-6 weeks before being valid. (One downside of doxyPEP is delay in the time to conclusive testing.)”

2. Correct.