Dimeric peptide-based inhibitors of postsynaptic density-95 (PSD-95) can reduce ischemic brain damage and inflammatory pain in rodents. To modify the pharmacokinetic profile we designed a series of fatty acid linked dimeric ligands, which potently inhibits PSD-95 and shows improved in vitro blood plasma stability. Subcutaneous administration in rats showed extended stability and sustained release of these ligands. This can facilitate new pharmacological uses of PSD-95 inhibitors and further exploration of PSD-95 as a drug target.