Cabotegravir free acid is the active pharmaceutical ingredient (API) form of cabotegravir, an integrase strand transfer inhibitor (INSTI). It is a potent antiretroviral agent specifically designed for the treatment and prevention of HIV-1 infection. Its primary application is as the key component in long-acting injectable formulations, such as Cabenuva (in combination with rilpivirine). This formulation allows for monthly or bimonthly administration, significantly improving treatment adherence compared to daily oral regimens. Cabotegravir works by inhibiting the viral integrase enzyme, thereby blocking the integration of HIV DNA into the host genome, a critical step in the HIV replication cycle. As an API, cabotegravir free acid is the chemical entity used in the manufacturing of the final drug product. It represents a major advancement in HIV therapy, offering a convenient and effective option for both treatment-naïve and treatment-experienced patients, as well as for pre-exposure prophylaxis (PrEP).