Understanding U=U (Undetectable = Untransmittable)
If the partner with HIV is on effective antiretroviral therapy and has an undetectable viral load (below 200 copies/mL), they cannot transmit HIV through sex. This is the U=U principle, backed by multiple large studies including PARTNER and HPTN 052.
U=U is one of the most important advances in HIV prevention. For many serodiscordant couples, it means the HIV-positive partner's treatment is the primary protection.
New data from CROI 2026: A study from Rakai, Uganda presented at CROI 2026 identified a small but quantifiable risk of transmission at viral loads between 200 and 1000 copies/mL. This does not change the U=U message for people with truly undetectable viral loads (<200), but it reinforces the importance of consistent viral suppression.
When Does PrEP Make Sense for Couples?
The CDC recommends that PrEP should not be withheld from anyone who requests it, even if their partner is virally suppressed. Reasons couples choose PrEP include:
- Peace of mind: Having an additional layer of protection reduces anxiety for both partners.
- Backup protection: Viral load can fluctuate temporarily due to illness, missed doses, or other factors.
- Outside partners: In non-monogamous relationships, PrEP protects against exposure from other partners.
- Conception: For couples trying to conceive, PrEP provides protection during condomless sex while ART maintains the HIV-positive partner's viral suppression.
- Viral load uncertainty: If the HIV-positive partner's adherence is inconsistent or viral load is between 200–1000 copies/mL.
PrEP for both of you
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PrEP During Conception and Pregnancy
For serodiscordant couples trying to have a baby:
- PrEP is considered safe during conception and pregnancy by the CDC
- The HIV-positive partner should have a confirmed undetectable viral load
- PrEP adds protection during the fertile window when condomless sex occurs
- Oral PrEP (Truvada) has the most safety data during pregnancy; discuss options with your provider
Talking About PrEP With Your Partner
Starting PrEP doesn't mean you don't trust your partner's treatment. Framing it as mutual protection rather than distrust helps:
- "I want to take care of my health so we can both feel comfortable"
- "This is an extra layer of safety, like wearing a seatbelt even though the car has airbags"
- "It actually helps me worry less, which is good for both of us"
Start PrEP privately and easily
MISTR offers discreet consultations and home delivery. Your PrEP, your decision, on your terms.
ANDR735
Using this code at signup helps us achieve our mission of getting free PrEP out to all who need it.