L-TheaninevsPEA (Palmitoylethanolamide)

L-Theanine (gamma-glutamylethylamide) crosses the blood-brain barrier via the large neutral amino acid transporter (LAT1/SLC7A5) and exerts anxiolytic effects through multiple pathways. It increases GABA synthesis by serving as a substrate for glutamate decarboxylase (GAD), elevating inhibitory tone without directly binding GABA-A receptors — avoiding sedation. It modulates serotonin by increasing tryptophan hydroxylase (TPH2) activity and raises dopamine levels in the prefrontal cortex via inhibition of dopamine reuptake. L-Theanine antagonizes glutamate binding at AMPA and kainate receptor subtypes (GluA1-4, GluK1-5), reducing excitatory neurotransmission and excitotoxicity risk. This glutamate antagonism, combined with increased GABA, drives the characteristic increase in alpha brain wave power (8-14 Hz) in the posterior parietal and occipital cortex — the EEG signature of relaxed alertness. When co-administered with caffeine, L-theanine attenuates caffeine-induced increases in blood pressure and anxiety by modulating sympathetic nervous system activation through alpha-2 adrenergic receptor pathways, while caffeine's dopaminergic and adenosine-blocking effects on focus and attention are preserved.

PEA activates PPAR-alpha (peroxisome proliferator-activated receptor alpha), a nuclear receptor that heterodimerizes with RXR and downregulates pro-inflammatory gene expression (NF-kB target genes, COX-2, iNOS, TNF-alpha). It has an 'entourage effect' on the endocannabinoid system — it inhibits the degradation of anandamide by fatty acid amide hydrolase (FAAH) through allosteric modulation or substrate competition, and upregulates CB2 receptor expression on immune cells. This provides anti-inflammatory and analgesic effects without directly activating CB1/CB2. PEA also activates GPR55 and GPR119. It inhibits mast cell degranulation (reducing histamine, tryptase, and cytokine release) and reduces microglial activation in the brain (inhibiting Iba1 expression and pro-inflammatory cytokine production). PEA may also modulate TRPV1.