Tenofovir Alafenamide Hemifumarate is the hemifumarate salt of tenofovir alafenamide, a lipophilic prodrug of the antiviral nucleotide analog tenofovir. It serves as a key active pharmaceutical ingredient (API) in formulations for treating HIV-1 infection, chronic hepatitis B, and as pre-exposure prophylaxis (PrEP). Compared to tenofovir disoproxil fumarate (TDF), it provides targeted intracellular delivery, lower systemic exposure, and reduced renal and bone toxicity risks. It acts by inhibiting viral reverse transcriptase, preventing DNA chain elongation.

This high-purity (≥94.5%) solid is intended for pharmaceutical research, development, synthesis of combination therapies, and manufacturing of antiviral drugs. CAS: 1392275-56-2. Molecular formula: C₂₃H₃₀N₅O₉P · 0.5 C₄H₄O₄. Molecular weight: 717.48 g/mol.