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BiologicalX

Comparison

L-Theanine vs Modafinil

Side-by-side of L-Theanine and Modafinil. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.

Effects at a glance

L-Theanine

  • Non-protein amino acid in tea; the most-replicated nootropic in the human RCT literature
  • Caffeine + theanine at 1:1 (100-200 mg each) is the gold-standard acute focus stack
  • Solo doses of 200-400 mg reduce subjective stress and improve sleep quality
  • Increases alpha-wave EEG activity within 30-45 minutes of 200 mg oral dose
  • Crosses blood-brain barrier; bioavailability high, half-life 60-90 minutes
  • Clean safety record; minimal interactions at supplement doses

Modafinil

  • FDA approved in 1998 for narcolepsy, with later additions for shift-work sleep disorder and OSA residual sleepiness
  • Schedule IV controlled substance in the US; prescription-only in EU, UK, Australia
  • Increases wakefulness via weak dopamine reuptake inhibition plus histaminergic, noradrenergic, and orexinergic activation
  • Long half-life of 12 to 15 hours requires morning dosing to avoid sleep disruption
  • Modest cognitive enhancement signal in non-sleep-deprived adults at 100 to 200 mg (Battleday meta-review 2015)
  • Substantial CYP3A4 induction reduces hormonal contraceptive efficacy; barrier methods recommended

Side-by-side

Attribute L-Theanine Modafinil
Category supplement pharmaceutical
Also known as theanine, gamma-glutamylethylamide Provigil, Modalert, Modvigil, diphenylmethylsulfinyl-acetamide
Half-life (hr) 1.5 13
Typical dose (mg) 200 200
Dosing frequency as needed (with caffeine) or daily daily, morning
Routes oral oral
Onset (hr) 0.5 1
Peak (hr) 1 3
Molecular weight 174.2 273.35
Molecular formula C7H14N2O3 C15H15NO2S
Mechanism Crosses BBB; modulates GABA/dopamine/serotonin (modest); increases alpha-wave EEG activity; dampens stress-induced sympathetic response without sedation. Weak dopamine reuptake inhibition plus downstream activation of histaminergic, noradrenergic, and orexinergic wake-promoting systems.
Legal status OTC dietary supplement Schedule IV (US); prescription-only globally; not a supplement
WADA status allowed banned
DEA / Rx OTC supplement Schedule IV
Pregnancy Insufficient supplement-dose data; tea-source intake safe Not recommended
CAS 3081-61-6 68693-11-8
PubChem CID 439378 4236
Wikidata Q909931 Q422968

Safety profile

L-Theanine

Common side effects

  • mild GI upset (rare)
  • headache (rare)

Contraindications

  • pregnancy / lactation (insufficient data at supplement doses)
  • concurrent strong GABAergics without caution

Interactions

  • caffeine: synergistic for acute focus; dampens jitter without blunting alertness(minor)
  • benzodiazepines / alcohol: potential additive sedation(minor)

Modafinil

Common side effects

  • headache
  • nausea
  • anxiety
  • insomnia (with late-day dosing)
  • dry mouth
  • mild blood pressure elevation

Contraindications

  • recent myocardial infarction
  • unstable angina
  • left ventricular hypertrophy
  • significant arrhythmia
  • history of Stevens-Johnson syndrome
  • psychotic disorders
  • pregnancy
  • concurrent MAOI use

Interactions

  • hormonal contraceptives: CYP3A4 induction reduces contraceptive efficacy; use barrier method(major)
  • cyclosporine: reduced cyclosporine levels via CYP3A4 induction(major)
  • warfarin: CYP2C9 inhibition raises INR(moderate)
  • phenytoin: CYP2C19 inhibition raises phenytoin levels(moderate)
  • MAOIs: potential hypertensive reaction(major)
  • classical stimulants (amphetamine, methylphenidate): additive cardiovascular and sleep-disruption effects(moderate)

Which Should You Take?

L-Theanine comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. Modafinil is the right call when one of the conditionals below applies.

  • If your priority is stress and HPA-axis regulation, pick L-Theanine.
  • If your priority is sleep onset or sleep quality, pick L-Theanine.
  • If your priority is wakefulness, pick Modafinil.
  • If your priority is fatigue resistance, pick Modafinil.

Edge case: If you want to avoid controlled substance, L-Theanine is the more accessible choice.

Default choice: L-Theanine. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Modafinil only if your priority sits squarely in the goals it owns above.

This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.

Common questions

What is the difference between L-Theanine and Modafinil?

L-Theanine and Modafinil differ in category (supplement vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.

Which has a longer half-life, L-Theanine or Modafinil?

L-Theanine half-life is 1.5 hours; Modafinil half-life is 13 hours.

Can you stack L-Theanine with Modafinil?

Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.

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