"PEP, or post-exposure prophylaxis, is a short course of HIV medicines that that can stop an HIV infection after the virus has entered a person’s body. It must be taken within 72 hours of exposure.
PEP is not a ‘morning after pill’ for HIV, and it’s not guaranteed to work. It’s meant as an emergency measure to be used as a last resort, such as if a condom fails during sex.
PEP is available on the NHS for free, but is only given to people who meet guidelines about its use.
The best place to get PEP is a sexual health or HIV clinic. If you need PEP over the weekend or outside of office hours, when clinics will often be closed, the best place to go is an Accident and Emergency department."
PEP is not normally available from GPs.