HLP003
Serotonergic psychedelic
From Wikipedia, the free encyclopedia
HLP003, or HLP-003, also known as deuterated psilocybin analogue and formerly as CYB003, is a serotonergic psychedelic related to psilocybin which is under development for the treatment of major depressive disorder, alcoholism, and other psychiatric disorders.[1][4][5][6][7][2][3] It is taken orally.[1] The drug is a tryptamine derivative and is a deuterated analogue of psilocybin and psilocin.[1][5][6][2]
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| Clinical data | |
|---|---|
| Other names | HLP003; HLP-003; CYB003; CYB-003; Deuterated psilocybin analogue; Deuterated psilocin analogue |
| Routes of administration | Oral[1] |
| Drug class | Serotonergic psychedelic[1][2] |
| ATC code |
|
| Pharmacokinetic data | |
| Onset of action | 30 minutes (Cmax) (rats)[3] |
| Elimination half-life | 45 minutes (rats)[3] |
Interactions
Pharmacology
The pharmacodynamic profile of HLP003, including its interactions with serotonin receptors and its effects in animals, is similar to that of psilocin.[2] As with psilocin, HLP003 is a potent agonist of the serotonin 5-HT2A receptor and produces psychedelic-like effects in animals.[2] 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.[3]
Chemistry

The exact chemical structure of HLP003 (i.e., which specific hydrogen atoms have been deuterated) does not yet seem to have been disclosed.[6][5] However, an INN of deupsilocin for a deuterated form of psilocin called d10-psilocin (decadeuteropsilocin) with CAS number 1435934-64-7 was proposed in 2023 and recommended in 2024.[8][9][10][11] This deuterated analogue of psilocin has been patented by Helus Pharma (formerly Cybin) as well as by Lennham Pharmaceuticals.[12][13][10] Helus Pharma has also patented other deuterated psilocin analogues.[14] Other deuterated drugs related to HLP003 or deupsilocin/d10-psilocin include the deuterated DMT analogues HLP004 (CYB004) and SPL028 and the deuterated phenethylamine HLP005 (CYB005).[5][15]
Research
In 2024, HLP003 received a breakthrough therapy designation from the U.S. FDA[16] 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.[1][4][17] Two phase 3 clinical trials for major depressive disorder are being initiated in November 2024 and February 2025.[1][4][17] The drug is under development by Helus Pharma (formerly Cybin).[1][4][17]