PrEP With Partner Resistant To Tenofovir?


Hi Damon, I would like to get on PreP very soon but my HIV+ partner is resistant to the tenofovir in Truvada. Does it mean PreP won't be able to protect me from the strain of HIV my partner has? Thank you.


Hi there, thank you for writing in with a great question. It sounds like you and your partner have made the conscious and informed decision for you to begin using PrEP. But will PrEP work for you if your partner is resistant to tenofovir?

The answer to that question lies primarily in your partner's viral load. If he has been undetectable for six months or longer, then he cannot transmit HIV to you or to anyone else ( The science behind "U=U" ["Undetectable=Untransmittable"] holds true even if the person with HIV has a resistant strain. With or without PrEP, he cannot transmit HIV to another person.

Now, let's say for argument sake that a person adherent to PrEP is exposed to detectable levels of HIV that are resistant to tenofovir and/or emtricitabine (the medications in Truvada). Would PrEP protect someone in that case?

That answer is slightly more uncertain. At this moment there are only three reported cases in the world of people acquiring HIV while adhering to PrEP. Two out of those two three acquired a strain of HIV that was resistant to tenofovir and emtricitabine, as well other commonly used HIV meds, suggesting that the persons who transmitted HIV had previously been using HIV treatment drugs and then stopped. At the same time, we don't have any way of knowing how often people on PrEP come into contact with those same resistant strains and do NOT acquire HIV. It is plausible, and quite possible, that people adherent to PrEP are encountering the same strains of resistant detectable HIV on a regular basis and not getting infected. We simply don't have the specific data.

I hope this is helpful and allows you and your partner to experience the type of intimacy and connection you seek.

For more information about PrEP, U=U, and "magnetic" relationships (where one person is HIV+ and one person is not), please come visit the international Facebook "PrEP Facts" group at