Cyclotraxin B TFA, a cyclic peptide, serves as a highly potent and selective non-competitive inhibitor of TrkB, effectively impeding BDNF-triggered TrkB activity without altering BDNF binding affinity, evidenced by an IC50 of 0.30 nM. It is capable of crossing the blood-brain barrier, demonstrating analgesic and anxiolytic-like behavioral effects [1] [2] [3].