N-sulfonylated and N-alkylated carprofen derivatives were investigated for their inhibition and modulation of gamma-secretase, which is associated with Alzheimer's disease. The introduction of a lipophilic substituent transformed the COX-2 inhibitor carprofen into a potent gamma-secretase modulator. Several compounds (e.g., 9p, 11f) caused selective reduction of Abeta42 and an increase of Abeta38. The most active compounds displayed activities in the low micromolar range and no effect on the gamma-secretase cleavage at the e-site.