HollisPEP vs PrEP: which one do you need?
PEP (post-exposure prophylaxis) is an emergency 28-day course started within 72 hours after a possible HIV exposure. PrEP (pre-exposure prophylaxis) is taken before exposure, on an ongoing basis, by people who are likely to be exposed to HIV. If you have had a possible exposure in the last 72 hours, you need PEP now. If you expect to be at risk again, ask your physician about PrEP afterwards.
The one-line difference
- PEP is for after. You take it because something has already happened.
- PrEP is for before. You take it because something might happen.
Both use HIV medicines to stop the virus establishing an infection. Neither protects against other STIs, so condoms and regular testing still matter.
Side by side
| PEP | PrEP | |
|---|---|---|
| When | After a possible exposure | Before possible exposures |
| Time limit | Must start within 72 hours | Ongoing, while you are at risk |
| How long | 28 days | As long as you need it |
| Medicines | Usually three HIV medicines | Usually two HIV medicines |
| Tests needed | Baseline, then HIV tests at 4 to 6 and 12 weeks | HIV test before starting, then every 3 months |
| Best for | A one-off exposure | Repeated or ongoing risk |
| Cost pattern | One-off course | Monthly |
When you need PEP
PEP is an emergency treatment for a single recent exposure, such as:
- a condom that broke or slipped with a partner whose HIV status you do not know
- unprotected anal or vaginal sex with a partner who has HIV and may not be on effective treatment
- sexual assault
- a needle-stick injury, or blood splashed into your eyes, mouth or broken skin
If it has been less than 72 hours, speak to a physician now. Every hour counts. Read where to get PEP in Dubai.
When PrEP makes more sense
PrEP is for people who are HIV-negative and likely to be exposed to HIV again, for example people who:
- have partners whose HIV status they do not know and do not always use condoms
- have a partner with HIV who is not on effective treatment or does not have an undetectable viral load
- have needed PEP more than once
Taken as prescribed, PrEP is highly effective at preventing HIV from sex.
Moving from PEP to PrEP
If you are on PEP and expect to be at risk again, you do not have to wait. Current guidance supports moving straight from PEP onto PrEP at the end of the 28-day course, once an HIV test confirms you are negative. Ask your physician about this during your PEP course.
What about a partner who is undetectable?
If your partner has HIV, is on treatment and has had an undetectable viral load for at least six months, the evidence shows they do not pass HIV on through sex. This is known as U=U, undetectable equals untransmittable. In that situation PEP is usually not needed. If you are not sure whether your partner's viral load is undetectable, speak to a physician; they can weigh what you know.
PEP and PrEP in the UAE
PEP medicines are prescription-only in the UAE and must be prescribed by a licensed physician after an assessment. HIV medicines used for prevention are available in the UAE on prescription, but PrEP services are still developing across the region, and how PrEP is prescribed and monitored can vary between providers. If you are interested in PrEP, ask a DHA-licensed physician how they would start and monitor it for you, including the tests needed before starting and every three months.
Be cautious about buying HIV medicines online from overseas sellers. You cannot be sure what you are receiving, and taking PrEP without HIV testing risks missing an existing infection.
What PEP and PrEP do not do
- They do not protect against chlamydia, gonorrhoea, syphilis, herpes or hepatitis C.
- They are not 100% effective, especially if doses are missed.
- They do not replace testing. Regular STI screening is part of both.
Frequently asked questions
Can I take PrEP instead of PEP after an exposure?
No. If you have had a possible exposure in the last 72 hours, you need PEP. PrEP is started before exposures and is not a substitute for PEP afterwards.
Can I go straight from PEP to PrEP?
Yes, current guidance supports moving straight onto PrEP at the end of a PEP course, once an HIV test confirms you are negative.
Do I need PEP if my partner is undetectable?
Usually not. People with HIV who are on treatment and have had an undetectable viral load for at least six months do not pass HIV on through sex. If you are unsure of their status, speak to a physician.
Does PrEP protect against other STIs?
No. PrEP only prevents HIV. Condoms and regular STI testing are still important.
Sources
- CDC. Clinical Guidelines for HIV Post-Exposure Prophylaxis (nPEP), 2025 update
- CDC. HIV prevention: PrEP
- CDC. HIV treatment as prevention (U=U)
- AlHammadi et al. PrEP in the Gulf region. International Journal of STD & AIDS (2025)
This article is general information, not medical or legal advice. Speak to a physician about your own situation. If you are in immediate danger, call 999.