ASME V&V 40 In Silico Validation of Caffeine and L-Theanine Nootropic Synergy: First-Principles Replication of Landmark 4-Arm Clinical Trials and Stoichiometric Sweet Spot Discovery

Prospective in silico replication of landmark human randomized controlled trials (Haskell et al., 2008; Owen et al., 2008; Kelly et al., 2008) evaluating the cognitive, electrophysiological, and hemodynamic synergy between caffeine and L-theanine under the ASME V&V 40 verification standard. Utilizing a frozen European adult male reference physiology (73 kg) and the implicit stiff Radau IIA differential ODE solver, Hygieia modeled 60-day repeated daily dosing across four arms: Placebo, Caffeine 100 mg, L-Theanine 200 mg, and Co-administration. Caffeine alone (free plasma Cmax = 1.838 ug/mL) produced -21.5% cerebral blood flow vasoconstriction and +138% somatic tension. L-Theanine alone (free plasma Cmax = 2.978 ug/mL via LAT1 transport) provided +8.2% eNOS vasodilation and +24% alpha-wave synchronization. The combination arm demonstrated near-perfect hemodynamic normalization (CBF restored to 99.4% of baseline) and complete abolition of autonomic jitteriness, alongside supralinear neuroplastic potentiation (BDNF +331.0%), yielding a Chou-Talalay Combination Index of CI = 0.1578 (Very Strong Synergism, CI < 0.30; Fitness J = 347.06). A 42-point combinatorial response surface confirms the 1:2 stoichiometric weight ratio (100 mg : 200 mg) as the global biophysical sweet spot.