Glp-Trp-OEt, a pyroglutamyl-tryptophan derivative, is a dipeptide Et ester[1].
References
[1] Giannola LI, et al. L-pyroglutamyl-L-tryptophan derivatives as potential drug carriers. II.: Permeation behaviour and stability in the gastro-intestinal tract. Pharmazie. 1996 Jul;51(7):487-9. PMID:8774840