CYB003

CYB003, or CYB-003, also known as deuterated psilocybin analogue, is a serotonergic psychedelic related to psilocybin which is under development for the treatment of major depressive disorder, alcoholism, and other psychiatric disorders. It is taken by mouth.
It is a tryptamine derivative and is a deuterated analogue of psilocybin and psilocin. The pharmacodynamic profile of CYB003, including its interactions with serotonin receptors and its effects in animals, is similar to that of psilocin. As with psilocin, CYB003 is a potent agonist of the serotonin 5-HT_2A receptor and produces psychedelic-like effects in animals. However, it was developed to have improved pharmacokinetic properties compared to psilocybin, including reduced variability in circulating levels, a faster onset of action, and a shorter duration.
In 2024, CYB003 received a breakthrough therapy designation from the U.S. FDA and was in phase 3 clinical trials for major depressive disorder and is in the preclinical stage of development for alcoholism and other psychiatric disorders. Two phase 3 clinical trials for major depressive disorder are being initiated in November 2024 and February 2025. The drug is under development by Cybin. The chemical structure of CYB003 has not yet been disclosed. However, Cybin patented deuterated tryptamines including the dideuterated psilocin analogue PI-α,α-d₂ in 2023. Other related drugs include the deuterated tryptamine CYB004, the deuterated phenethylamine CYB005, and the phenethylamine CYB210010.
An of deupsilocin for a deuterated form of psilocin called d₁₀-psilocin with CAS number 1435934-64-7 was proposed in 2023 and recommended in 2024. This deuterated analogue of psilocin was patented in 2021 by Lennham Pharmaceuticals.