Warning Flags™ is our proprietary risk-scoring model for CNS drug development programs. It evaluates candidates across target validation, ADME, safety, CMC, clinical, regulatory, IP, and financial dimensions, generating a score from 0 to 66+ mapped to a twelve-tier color scale from Green (clear investment conditions) to Black (do not commit capital). This edition runs four entactogen candidates through the model simultaneously.
The MDMA-AT failure in 2024 left a field, not a void. The FDA's rejection of the Lykos NDA, citing functional unblinding, inadequate data integrity, and unresolved risks, did not invalidate the therapeutic thesis. It raised the bar for what a fundable entactogen program needs to look like. Four candidates now compete to clear it.
We scored all four against the same parameters: PTSD indication, current development stage, publicly available data only.
Hypothetical best-case NCE: 2.0 (Green Flag). Methylone (TSND-201): 4.0 (Green/Striped Flag). MBDB: 40.8 (Purple Flag). MDEA: 43.8 (Purple Flag).
The gap between the first two and the second two is 37 points. That number tells the story of this field more clearly than any single pharmacological comparison.
MBDB and MDEA are among the most pharmacologically characterized entactogen candidates outside of MDMA and MDA1. Both were characterized by Alexander Shulgin, with detailed notes in PiHKAL. Neither has entered a clinical trial. The Purple Flag at preclinical is not a pharmacological verdict. It reflects two critical structural findings that apply to any known molecule at this stage: no GLP-compliant toxicology package exists in the public literature, and composition-of-matter patents, given the age of both compounds, have almost certainly expired. Both molecules are effectively public domain. Any IP strategy built around them depends on method-of-use patents alone, a structurally weaker position than a true NCE. For any organization developing these compounds, the path to IND starts from a thin public data package and a weak IP foundation, and that is capital-intensive regardless of how interesting the pharmacology is.
The 3-point gap between MBDB and MDEA traces to two findings. MDEA carries a broader monoamine release profile, with meaningful dopamine and norepinephrine output alongside serotonin, plus an inferred hERG/QTc concern from that broader catecholamine activity. MBDB is essentially dopamine-silent, with an EC50 for dopamine release exceeding 100,000 nM versus 540 nM for serotonin (Nagai et al., 2007). That selectivity advantage is real, but it does not move the flag. Both compounds still carry a neurotoxicity signal: MDEA was approximately one-fourth as potent as MDMA in producing long-term serotonin depletion in rodents (Ricaurte et al., 1987), and MBDB produces reduced but not absent serotonergic neurotoxicity. Safer than MDMA. Not clean.
“On the current evidence, no program in this field has cleared those hurdles. Methylone is simply the furthest along.”
Methylone tells a different story. At Phase 2 with positive JAMA Psychiatry data, Breakthrough Therapy Designation, a Priority Review Voucher, and a $1.2 billion Otsuka acquisition behind it, the program generates 18 positive findings that overwhelm its residual concerns. The two remaining high flags (moderate patent estate and crowded competitive landscape) are inherited constraints of any known molecule in an active field, not program-specific failures. Green/Striped at Phase 2 is a strong result
The hypothetical best-case NCE scores Green at preclinical. True NCE origin, clean composition-of-matter patent, full GLP package, high selectivity, no neurotoxic signal, experienced team. At 2.0, it edges out methylone by two points, but methylone is already in Phase 3 recruitment with a major pharma partner. The hypothetical NCE still has to survive IND, Phase 1, and Phase 2 before it can make that comparison meaningful.
That is the investment read. The known molecules without development programs behind them are not investable at current stage, not because the pharmacology fails, but because the structural gaps are too large. Methylone has already cleared those gaps and is executing. The purpose-built NCE represents the ceiling of what the field could look like, but ceiling and present value are different things.
Methylone is not a winner. It is a leader. Phase 3 can fail. DEA scheduling is not guaranteed. The blinding problem that contributed to the Lykos NDA rejection hasn't been solved for any entactogen. On the current evidence, no program in this field has cleared those hurdles. Methylone is simply the furthest along.
Warning Flags gives a clear answer on what that program needs to look like. It does not yet exist in the public domain.
1: MDA was excluded from this analysis. Its neurotoxicity profile exceeds MDMA's, and no active IND-stage program exists.
References
- Nagai, T., Nonaka, R., Satoh, K., Hisashi, K., & Kamimura, H. (2007). The effects of non-medically used psychoactive drugs on monoamine neurotransmission in rat brain. Forensic Science International, 173(2–3), 106–114.
- Ricaurte, G.A., Finnegan, K.F., Nichols, D.E., DeLanney, L.E., Irwin, I., & Langston, J.W. (1987). 3,4-Methylenedioxyethylamphetamine (MDE), a novel analogue of MDMA, produces long-lasting depletion of serotonin in the rat brain. European Journal of Pharmacology, 137, 265–268.
- Shulgin, A., & Shulgin, A. (1991). PiHKAL: A Chemical Love Story. Transform Press.
- Jones A, Warner-Schmidt J, Kwak H, Stogniew M, Mandell B, Ching THW, Stein MB, Kelmendi B. Efficacy and safety of the neuroplastogen TSND-201 for the treatment of PTSD: a randomized clinical trial. JAMA Psychiatry. 2026;83(5):469–477. doi:10.1001/jamapsychiatry.2025.4625