Nootropics

NSI-189

Evidence: moderate_human

Mechanism of Action

Benzylpiperizine-aminopyridine compound that stimulates neurogenesis of human hippocampus-derived neural stem cells in vitro and increases hippocampal volume in vivo. Mechanism is independent of serotonin or norepinephrine reuptake inhibition — fundamentally distinct from traditional antidepressants. Activates the TrkB receptor (BDNF receptor) and downstream Akt/PI3K signaling pathways to promote synaptic plasticity, long-term potentiation, and neuronal survival. Enhances BDNF expression in hippocampal subregions critical for memory consolidation and mood regulation. Originally developed as ALTO-100 (Alto Neuroscience) for treatment-resistant depression with cognitive impairment.

Dosing Protocol

Standard: 40 mg once daily (for educational context — investigational compound, not approved for any indication)

Maintenance: 40 mg/day based on Phase 2 data suggesting this dose has the best benefit-risk profile

Administration: oral

Timing: Once daily, time of day not definitively established from clinical data. With or without food.

Duration: Phase 2 trial used 12-week treatment duration. Long-term safety data unavailable.

Notes

FOR EDUCATIONAL PURPOSES ONLY — NSI-189/ALTO-100 is an investigational compound with no regulatory approval. The Phase 2 trial (Fava et al. 2019, n=220) failed its primary endpoint (MADRS) but showed statistically significant improvements on secondary measures of cognition and self-rated depression at the 40mg dose. The 80mg dose showed benefit specifically in moderately (not severely) depressed patients. The pro-cognitive effects are the most compelling aspect — improvements on CogScreen measures with effect sizes up to d=1.12, which is unusually large. The hippocampal neurogenesis mechanism is genuinely novel and represents a new pharmacological approach distinct from all existing antidepressants. Alto Neuroscience is using biomarker-guided patient selection (EEG phenotyping) to improve signal detection in ongoing trials. The compound's future depends on whether this precision psychiatry approach can demonstrate efficacy in targeted populations.

Stacking

  • Lion's Mane (synergistic neurogenesis)
  • Omega-3 (DHA)
  • Magnesium L-Threonate

Interactions

  • SSRIs/SNRIs [MEDIUM] — NSI-189 mechanism is distinct from monoamine reuptake inhibition, but combined effects on hippocampal plasticity are unstudied in combination
  • Other neurogenic compounds (BDNF modulators) [LOW] — Theoretical additive neurogenic effects — safety profile of combinations is unknown

Contraindications

  • Pregnancy and lactation (no safety data; neurogenic compounds carry theoretical teratogenic risk)
  • History of brain tumors (neurogenic stimulation could theoretically promote growth — speculative)
  • No regulatory approval for any indication — investigational use only

Side Effects

  • Headache
  • GI discomfort
  • Dizziness
  • Somnolence
  • Dry mouth
  • Generally well-tolerated in Phase 1b and Phase 2 trials

Key Papers

  • 10.1038/s41380-018-0334-8
  • 10.1038/npp.2016.37
  • 10.1016/j.neuropharm.2018.09.025

Source Quality

Investigational new drug — not commercially available through legitimate pharmaceutical channels. Neuralstem developed the compound, later sold to Alto Neuroscience (now ALTO-100). Available through research chemical vendors, but purity and identity verification are essential — demand mass spectrometry and HPLC analysis from vendors. No pharmaceutical-grade product exists for consumer use.

Disclaimer: This information is for educational purposes only and is not medical advice. BioAccelera Labs does not diagnose, treat, or prescribe. Consult a licensed healthcare provider before using any compound.

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