Hi doctors my friend took pep medication for about 28 days when he had had sex with someone suspected to be hiv positive. may i ask if is there any other medication available like pep but can be taken for a shorter period of time compared to 28days?

PEP and PrEP: It is unknown whether post-exposure prophylaxis (PEP) would be effective if taken less than 4 weeks. It might work, but has not been studied. In addition, under treatment could be dangerous, possibly allowing HIV infection to take hold and also making the virus resistant to treatment. People with ongoing risk should consider PRE-exposore prophylaxis (PrEP), i.e. daily anti-HIV treatment.