Neuropharmacology research model

Concerta across the active day.

A dose-time model connecting OROS methylphenidate exposure to DAT/NET occupancy and relative extracellular dopamine and norepinephrine signals.

Not a dosing guide. Human studies do not directly measure minute-by-minute synaptic NE and DA after Concerta. The transmitter curves are my evidence-anchored inferences, and I hold them with substantial uncertainty. The 2026 US and Australian product information cap recommended adult dosing at 72 mg/day.

Plasma exposure

Plasma MPH

Central adult estimate; dose-proportional scaling from a 54 mg reference profile.

Transporter occupancy

DATNET

Saturable PET-informed engagement; EC50 5.7 ng/mL (DAT), 4.7 ng/mL (NET).

Relative extracellular transmitter signal

DANE proxy

Striatal DA is human-PET anchored; NET-rich-region NE magnitude is hypothesis-grade.

Move across the figure, or focus it and use the arrow keys, to read every curve at one moment. Shaded hours: modeled plasma above the DAT EC50 of 5.7 ng/mL, which is modeled DAT occupancy above 50%. Faint lines: the other doses, for comparison.

How the curves are computed

Plasma: C(t) = r(t) × 12.2 ng/mL × dose / 54 mg, where r(t) is the 54 mg reference profile, interpolated linearly between r = 0, 0.055, 0.14, 0.22, 0.24, 0.28, 0.39, 0.72, 1, 0.87, 0.58, 0.34, 0.19 at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 14, 16 h.
Occupancy: DAT = 100 × C / (C + 5.7), NET = 100 × C / (C + 4.7), in %.
Transmitter: DA increase = DAT × 16 / 60, NE proxy = NET × 0.25, in % above baseline.

What can be inferred

Concerta produces an early 1-2 hour shoulder, a broader 6-8 hour peak, and a gradual decline. Plasma exposure rises approximately in proportion to dose over 54-108 mg, but transporter occupancy is saturable. The modeled difference between 90 and 108 mg is therefore smaller for extracellular effect than for plasma concentration.

Regional meaning

The DA curve represents a striatal signal, where DAT is prominent. In prefrontal cortex, NET also clears dopamine, so I have not drawn a single whole-brain dopamine curve: I think it would mislead.

Uncertainty

Body size, metabolism, age, food timing, neural firing, sleep, prior treatment, comorbidity, interacting medicines, and the formulation itself can move an individual far from the central trace. I do not claim the plot predicts subjective experience or clinical benefit.

Download the 7-page report (PDF)

Research visualization by Benjamin Haire - 3 September 2026. Prescription medication decisions belong with the prescribing clinician.