TAK-653 / Osavampator

What it is

TAK-653, now called osavampator or NBI-1065845, is an investigational oral small molecule that positively modulates AMPA receptors. It has little direct agonistic activity: rather than strongly activating a receptor on its own, it amplifies the receptor response when endogenous glutamate is present. That activity-dependent profile was designed to strengthen useful AMPA signaling while reducing the excessive-excitation liability that limited earlier compounds in the class.

The human evidence is stronger for depression than cognition

In the 183-person Phase 2 SAVITRI study, 1 mg/day improved depression scores versus placebo at days 28 and 56. The 3 mg/day arm moved in the same direction but did not reach statistical significance. That non-linear result matters: a larger exposure cannot be assumed to produce a larger benefit. The detailed results currently come from a sponsor conference poster rather than a full peer-reviewed outcomes paper.

Healthy-human studies establish target engagement, not enhancement

A 24-person crossover study found that a single 6 mg dose increased motor-cortex excitability measured with transcranial magnetic stimulation. Companion testing reported small effects on adaptive tracking, eye-movement, and Stroop measures without a subjective high, euphoria, or obvious mood disturbance. These results show brain penetration and a subtle stimulatory profile; they do not establish durable improvement in memory, attention, productivity, or motivation in healthy people.

Why the recorded amount is 2.5 mg/day

The available product contains 2.5 mg in each pill, so the planned exposure is one whole pill per day. This amount was selected because it is the fixed manufactured unit on hand, not because 2.5 mg has been validated as an optimal cognitive dose. It lies between the positive 1 mg and nonsignificant 3 mg Phase 2 arms and has not been directly tested as a repeated-dose cognitive regimen.

Why Bromantane stays and Modafiendz stops

Bromantane already produces a stable personal improvement in mood regulation and stress tolerance. It remains unchanged so this experiment asks a narrower incremental question: does TAK-653 add vigilant attention, mental clarity, sustained engagement, or lower cognitive fatigue beyond that established baseline? Modafiendz will not be used during the practice week, scored baseline, active phase, or initial follow-up because its irregular wakefulness effect would make the cognitive and sleep results harder to interpret.

Safety boundary

Phase 1 exposed healthy volunteers to single doses through 18 mg and repeated doses through 9 mg/day for 13 days without a serious adverse event. In the eight-week Phase 2 study, headache, nasopharyngitis, insomnia, and somnolence were among the reported events; no seizure, tremor, serious adverse event, or death was reported. These relatively small and short studies cannot establish rare-event risk or long-term safety in healthy people. Persistent insomnia, escalating headache, agitation, tremor, a meaningful blood-pressure change, or a new neurological symptom would trigger reassessment. A severe or acute symptom is a medical issue rather than an experiment datapoint.

Sources

• Suzuki et al., Scientific Reports, 2021 — AMPA-receptor binding, agonist dependence, neuronal currents, BDNF, and preclinical cognition.
• O'Donnell et al., Translational Psychiatry, 2021 — human and rat TMS evidence of cortical target engagement.
• Dijkstra et al., Translational Psychiatry, 2022 — acute CNS and cognitive-task effects in healthy volunteers.
• SAVITRI Phase 2 poster — eight-week 1 mg, 3 mg, and placebo efficacy and safety results.
• NCT02561156 — first-in-human single- and multiple-dose results.
• NCT02561156 Phase 1 protocol — fasted and fed dosing procedures, pharmacokinetic sampling, and safety monitoring.

Research question

After a stable baseline, does 2.5 mg/day of oral TAK-653 produce a repeatable improvement in vigilant attention, mental clarity, sustained engagement, or cognitive fatigue on top of continued Bromantane without a meaningful sleep, blood-pressure, anxiety, activation, or headache penalty?

Phases and dates

• September 1–7: PVT familiarization; scores are discarded.
• September 8–14: scored no-TAK baseline.
• September 15–November 9: 56-day active phase at one 2.5 mg pill per day.
• November 10–23: initial off-product follow-up.

The scored baseline and post-Cerebrolysin observation period are accepted as stable enough to begin active dosing on September 15. Because TAK-653 has a long reported half-life, November 10–16 will be treated as the elimination week and November 17–23 as the cleaner off-product comparison.

Daily vigilance test

The objective measurement is one three-minute PersonalPVT session every morning on the same computer, browser, keyboard, and display. It will be completed before Bromantane, TAK-653, caffeine, pre-workout, or training, with notifications silenced and no music or conversation. The September 15 session is the final pre-first-dose measurement. Beginning September 16, the same session becomes the pre-dose trough measurement: TAK-653 remains in the body from prior doses because its reported terminal half-life is approximately 33 to 48 hours. The first 7 to 10 active days will be treated as an accumulation period rather than pooled automatically with the later, more stable exposure period.

The two retained outcomes are mean reaction time and lapses beyond the configured threshold. PersonalPVT stores results in the browser, graphs the history, and exports CSV data. The file will be exported weekly so the record does not depend on one browser's local storage.

Open the fixed three-minute PersonalPVT

Dose timing and daily order

The morning order remains PVT first, followed by scheduled blood pressure when applicable, then the existing fasted Bromantane and pre-workout routine. TAK-653 is kept out of the immediate pre-workout window. One 2.5 mg pill is taken after training with or immediately after the daily large meal, normally around 10 AM. The dose should remain within the same 30-minute window and in the same relationship to the meal each day. On a non-training day, the same clock time and meal relationship replace the workout anchor.

This separation prevents the first acute exposure from occurring during training and makes the daily sequence easier to reproduce. It does not remove the biological overlap with Bromantane after TAK-653 accumulates, and no human interaction study of that combination was identified.

Daily subjective log

Record each item from 0 to 10 at the same evening check-in, reflecting the day as a whole. A higher number always means more of the named experience: mental clarity, sustained engagement, mood stability, task-initiation friction, cognitive fatigue, stress reactivity, anxiety or overactivation, and headache or head pressure. The first three are positive outcomes; the remaining five are costs or barriers.

WHOOP sleep and recovery context

WHOOP will supply total sleep, sleep performance, sleep efficiency, disturbances, resting heart rate, HRV, and recovery. Total sleep and sleep efficiency are the core tolerability outcomes. Recovery, HRV, and resting heart rate remain supporting context because training load and other active metabolic experiments can move them independently of TAK-653.

Blood pressure

Measure blood pressure on three fixed mornings each week under the same pre-caffeine conditions. Complete the PVT first, then sit quietly for five minutes and take two readings one minute apart, retaining their average. Extra measurements taken because of a symptom will be labeled separately rather than mixed into the scheduled series.

What is deliberately excluded

Focus blocks, work minutes, and other productivity outputs are not endpoints because life circumstances move them too strongly. There is also no broad rotating cognitive battery. One repeated vigilance test is more likely to be completed consistently and interpreted cleanly than several attention, memory, and reaction-time tasks. A second daily post-dose PVT is also excluded because it would overlap with training, caffeine, pre-workout, and variable post-workout conditions.

Confounder control

Bromantane remains fixed. Modafiendz remains absent from September 1 through the November 23 follow-up. Caffeine, pre-workout, testing device, morning test order, TAK-653 clock time, and its relationship to the daily large meal stay as consistent as practical. MemoProve, Cortexin, oxiracetam, Semax, and other new cognitive interventions will not begin during the experiment. Illness, travel, severe sleep disruption, device changes, late doses, or interrupted tests will be annotated rather than silently removed.

Review points and success rule

Tolerability is reviewed after the first active week, while efficacy is reviewed at days 28 and 56 without changing the amount. TAK-653 earns a helpful result only if mean reaction time or lapse frequency improves beyond the scored baseline's ordinary variation, the improvement appears in at least three of the final four weekly summaries, and at least one matching subjective outcome improves in the same direction. A result accompanied by meaningfully worse sleep, sustained anxiety or activation, persistent headache, or a blood-pressure penalty will not count as helpful.

Why 120 pills do not imply 120 continuous days

Day 56 remains the first endpoint because it matches the longest controlled efficacy phase currently reported for osavampator. The remaining pills preserve options. If a promising signal appears, the initial off-product period can test whether it fades, and a later fixed-dose rechallenge can test whether it returns. That withdrawal-and-return pattern would provide more useful personal evidence than automatically extending continuous exposure to four months.