Sulindac sulfide is primarily used in medical research and treatment due to its anti-inflammatory and anti-cancer properties. It is an active metabolite of sulindac, a nonsteroidal anti-inflammatory drug (NSAID). In clinical settings, it is studied for its potential to inhibit the growth of certain cancer cells, particularly in colorectal cancer, by inducing apoptosis and suppressing tumor progression. Additionally, it is investigated for its role in reducing inflammation in conditions like arthritis. Its ability to modulate specific enzymes and pathways makes it a valuable compound in both therapeutic and experimental contexts.