Psychedelic · TSND-201

Methylone (TSND-201)

  • Breakthrough Therapy
  • Commissioner's National Priority Voucher

Methylone (3,4-methylenedioxy-N-methylcathinone, bk-MDMA), an entactogen/neuroplastogen developed as TSND-201 for PTSD. Releases serotonin, norepinephrine and dopamine without direct 5-HT2A agonism, producing shorter, milder effects than MDMA. Transcend was acquired by Otsuka (completed 15 Jun 2026).

Also known as: TSND-201, Methylone, bk-MDMA

Modality
Psychedelic
Chemical class
Substituted cathinone, Methylenedioxyphenethylamine
DEA schedule
Schedule I
Chemistry
Racemic
Mechanism
SERT releaser
Highest phase
Phase 3
Designations
Breakthrough Therapy, Commissioner's National Priority Voucher
Trials
3 tracked · 1 recruiting · 60 sites

Mechanism of action

Methylone is a substrate-type releaser at the serotonin, norepinephrine and dopamine transporters (SERT/NET/DAT) with no direct 5-HT2A/2C activity; downstream it engages BDNF/mTOR signaling ('neuroplastogen'), enhancing fear-extinction learning.

TargetActionAffinity
SERTprimarySLC6A4Releaser
DATSLC6A3Releaser
NETSLC6A2Releaser

Formulations

FormulationRouteRegimenPharmacokinetics
TSND-201 oral (IMPACT-1)proprietary oral formulation of methylone
Four once-weekly oral dosing sessions (150 mg on day 1, then 100 mg on days 8, 15, 22) in the Phase 2 IMPACT-1 PTSD trial
OralOnce weeklyt½ 6.4 h · Tmax 2 h

Development timeline

Phase 3Apr 2026 – Jun 2026
  1. Otsuka completed acquisition of Transcend Therapeutics; program continues under Otsuka.
  2. Phase 3 EMPOWER-1 (NCT07456696) initiated/recruiting for PTSD.
Phase 2Jul 2025
  1. FDA granted Breakthrough Therapy Designation for TSND-201 in PTSD.
Phase 1/2Feb 2025
  1. IMPACT-1 (NCT05741710) met primary endpoint: placebo-adjusted CAPS-5 -9.64 at Day 64 (p=0.011).

Methylone (TSND-201) for Post-traumatic stress disorder

Phase 3RecruitingPost-traumatic stress disorder indication →

TSND-201 (methylone) for PTSD. Phase 1/2 IMPACT-1 met its primary endpoint (placebo-adjusted CAPS-5 -9.64 at Day 64, p=0.011; published in JAMA Psychiatry). FDA Breakthrough Therapy granted 10 Jul 2025; pivotal Phase 3 EMPOWER-1 began enrolling Apr 2026. Otsuka completed acquisition of Transcend 15 Jun 2026.

Clinical trials

NCT07456696EMPOWER-1Phase 3Recruitingn=300

Phase 3 Evaluation of TSND-201 for the Treatment of PTSD (EMPOWER-1)

Started Apr 2026· Primary completion Dec 2027· 📍 32 sites across 1 country (United States)

NCT06215261IMPACT-2Phase 2Completedn=62

Safety and Efficacy of Methylone for PTSD (IMPACT-2)

Started Apr 2024· Primary completion Sept 2025· 📍 12 sites across 3 countries (United States, Australia, United Kingdom)

NCT05741710IMPACT-1Phase 1/2Completedn=79

A Study to Assess Methylone in the Treatment of PTSD (IMPACT-1)

Started Mar 2023· Primary completion Feb 2025· 📍 16 sites across 3 countries (United States, United Kingdom, Ireland)

metprimaryCAPS-5 change at Day 64 (placebo-adjusted) — -9.64 points (0.011)

Response 57.1% vs 19.2% (p=0.002), remission 32.1% vs 11.5%, loss of diagnosis 60.7% vs 30.8%. Published in JAMA Psychiatry.

Conference coverage

TSND-201 appears in 3 CNS Pulse conference abstracts:

Identifiers

Sources

  1. An Evaluation of the Safety and Efficacy of TSND-201 for the Treatment of PTSD (EMPOWER-1) — ClinicalTrials.gov
  2. Efficacy and Safety of the Neuroplastogen TSND-201 for the Treatment of PTSD: A Randomized Clinical Trial (IMPACT-1) — JAMA Psychiatry / PMC
  3. clinicaltrials.gov — ClinicalTrials.gov
  4. transcendtherapeutics.com — Reference
  5. transcendtherapeutics.com — Reference
  6. transcendtherapeutics.com — Reference
  7. IMPACT-1 (NCT05741710) — ClinicalTrials.gov
  8. Otsuka Pharmaceutical Completes Acquisition of Transcend Therapeutics — Otsuka Pharmaceutical
  9. Transcend Therapeutics Receives Breakthrough Therapy Designation for TSND-201 (methylone) for PTSD — Transcend Therapeutics