Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are highly specific and potent allosteric inhibitors of HIV-1 reverse transcriptase. Dapivirine, a diarylpyrimidine derivative of the potent NNRTI efavirenz (Item No. 14412), inhibits HIV-1 reverse transcriptase with an IC50 value of 24 nM in vitro. It impedes the late stages of HIV-1 infection by interfering with HIV-1 Gag-Pol polyprotein processing.