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superstack

long-haul wakefulness

a long day on too little sleep, and the one pair here that needs care

  1. Modafinil
    the wakefulness base
    Established
  2. Caffeine
    top-up; the pair the conflict card flags
    Established
  3. L-Theanine
    softens the stimulant edge
    Human RCTs

Read from the entries

computed from each compound's own data at build; nothing here is typed in

Conflictscaution

3 pairs read: 1 caution, 2 compatible.

  • Modafinil + Caffeine

    Additive stimulation of arousal and heart rate, and a larger combined hit to sleep; not studied as a combination for cognition

  • Modafinil + L-Theanine
  • Caffeine + L-Theanine
Overlap

No shared class or direct target: each item pulls a different lever.

Shared effects
  • Attention3 of 3
  • Wakefulness2 of 3
  • Alertness2 of 3
Evidence floor

A stack is only as well supported as its weakest item.

Human RCTs

set by L-Theanine

  • Modafinil5 papers
    2002 · RCT · Effect of modafinil on the pharmacokinetics of ethinyl estradiol and triazolam in healthy volunteers.2015 · meta-analysis · Modafinil for cognitive neuroenhancement in healthy non-sleep-deprived subjects: A systematic review.2016 · RCT · Dopamine Transporter Correlates and Occupancy by Modafinil in Cocaine-Dependent Patients: A Controlled Study With High-Resolution PET and [(11)C]-PE2I.2020 · review · Pharmacokinetic and pharmacodynamic of the cognitive enhancer modafinil: Relevant clinical and forensic aspects.2020 · meta-analysis · How effective are pharmaceuticals for cognitive enhancement in healthy adults? A series of meta-analyses of cognitive performance during acute administration of modafinil, methylphenidate and D-amphetamine.
  • Caffeine8 papers
    2004 · review · A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features.2005 · RCT · Fluvoxamine impairs single-dose caffeine clearance without altering caffeine pharmacodynamics.2013 · RCT · Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed.2014 · meta-analysis · Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis.2015 · review · Caffeine: cognitive and physical performance enhancer or psychoactive drug?2015 · RCT · Effects of caffeine on the human circadian clock in vivo and in vitro.2016 · review · A review of caffeine's effects on cognitive, physical and occupational performance.2018 · review · Interindividual Differences in Caffeine Metabolism and Factors Driving Caffeine Consumption.
  • L-Theanine10 papers
    2008 · RCT · The combined effects of L-theanine and caffeine on cognitive performance and mood.2010 · RCT · L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness.2010 · RCT · The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness.2014 · meta-analysis · Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis.2017 · RCT · Acute effects of theanine, caffeine and theanine-caffeine combination on attention.2019 · RCT · Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial.2019 · review · Psychotropic effects of L-theanine and its clinical properties: From the management of anxiety and stress to a potential use in schizophrenia.2020 · meta-analysis · The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review.2025 · meta-analysis · The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis.2025 · meta-analysis · Effects of Tea (Camellia sinensis) or its Bioactive Compounds l-Theanine or l-Theanine plus Caffeine on Cognition, Sleep, and Mood in Healthy Participants: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Why it works

Modafinil is licensed for shift work sleep disorder [1], and that is the scenario this stack is built around. Adding Caffeine is common, and the conflict card on this page marks it as a caution pair. Both push arousal and heart rate up, and together they make the sleep debt worse afterwards.

Worth knowing

Modafinil is a prescription drug that induces CYP3A4 and can weaken hormonal contraceptives [2]. In rested people its cognitive benefit is small [3]. It is a tool for sleepiness, not a study aid.

References

  1. [1]
  2. [2]
    Effect of modafinil on the pharmacokinetics of ethinyl estradiol and triazolam in healthy volunteers.
    Robertson P, Hellriegel ET, Arora S et al.Clin Pharmacol Ther 2002RCT · humanPMID 11823757◌ unreviewed
  3. [3]

Not a protocol and not a recommendation to combine anything. Read the individual entries, and talk to a clinician before taking any of this, particularly anything labelled prescription drug.