The basic but gold standard of PEP mediation is the 3rd and 4th generation of drugs that are taken for 30 days. Tenofovir (TDF) combined with emtricitabine (FTC) is what every doctor prescribes. Many companies make these drugs but the one that your doctor prescribes will be the best. There are some people that are HIV drug-resistant so the dosage will need to the stronger. Doctors know best here. The drugs are approved by the American Centre for Disease Control so you do not need to worry about their authenticity.