When can you have sex after starting Pre-Exposure Prophylaxis (PrEP) with Truvada (Emtricitabine/Tenofovir Disoproxil Fumarate)?

When Can You Have Sex After Starting PrEP?

For receptive anal sex, you can have sex after 7 days of daily TDF/FTC (Truvada) dosing, though some guidelines suggest protection may be achieved in as little as 2-3 days with adequate dosing; for receptive vaginal sex, you must wait a full 7 days of daily dosing before having sex. 1

Time to Protection by Type of Sexual Activity

Receptive Anal Sex

• Protection is achieved within 7 days of daily dosing, though the International Antiviral Society-USA guidelines indicate that with adequate dosing, protection for receptive anal sex can occur more rapidly, within 2-3 days 1
• Start with a double dose of TDF/FTC on day 1, followed by single daily tablets thereafter to achieve protective drug levels more rapidly 1
• Daily dosing should continue until at least 2 doses after last sexual activity for rectal exposures 2

Receptive Vaginal Sex

• A full 7 days of daily dosing is required before having receptive vaginal sex 1
• This longer window is necessary because tenofovir concentrates at 10-fold lower levels in vaginal tissue compared to rectal tissue, and clearance is faster 1, 3
• For vaginal, neovaginal, or "front-hole" exposures, dosing must continue until at least 7 days after last sexual activity 2
• Women must take PrEP 6 to 7 days per week to maximize efficacy, unlike men who may achieve protection with at least 4 days per week 3

Critical Dosing Considerations

Daily PrEP Regimen

• The standard dose is one tablet daily (TDF 300 mg/FTC 200 mg) 4
• Daily dosing is the recommended regimen for all populations at risk of HIV through sexual exposure 1
• For optimal protection, particularly for individuals with vaginal tissue, daily dosing without interruption is required 4

On-Demand (2-1-1) PrEP

• On-demand PrEP is only validated for cisgender men and transgender women having planned receptive anal sex, not for receptive vaginal exposures 1
• The 2-1-1 schedule consists of: 2 doses taken 2-24 hours before sex, 1 dose 24 hours after the first dose, and 1 dose 24 hours after the second dose 1
• This regimen showed 86% risk reduction in the IPERGAY study among men who have sex with men 1
• Do not use on-demand dosing for vaginal exposures as it has not been validated for this route 1

Common Pitfalls to Avoid

• Never reduce dosing frequency to every other day, as daily dosing is required for optimal protection, especially for vaginal tissue where tenofovir concentrates at much lower levels 4
• Do not assume protection is immediate upon starting PrEP—the full 7-day window must be respected for vaginal exposures 1
• On-demand PrEP with TAF/FTC has not been validated; only TDF/FTC has evidence for the 2-1-1 dosing schedule 1
• A combination HIV antigen-antibody assay must be performed within 7 days before starting PrEP to exclude HIV infection 1

Monitoring Requirements

• HIV testing should occur at 1 month after initiation and quarterly thereafter 2
• PrEP prescriptions should not exceed 90 days without interval HIV testing 2
• STI testing should be performed quarterly 2
• At the first visit, prescribe no more than 30 pills; at revisits, no more than 90 tablets 5