L-Theanine
The Calm Focus Amino Acid
L-theanine is an amino acid found in tea leaves, particularly green tea. It's the molecule behind tea's signature feel: calm focus, without the buzz of coffee or the drowsiness of relaxation.
Today, L-theanine is one of the most studied amino acids for cognitive support. The research keeps coming back to alpha brain wave activity, the brain state associated with calm, focused attention.
How L-Theanine Works
L-theanine is one of the few amino acids studied for direct effects on brain state. Four mechanisms explain why.
1.Promotes alpha brain wave activity.
L-theanine has been studied for its role in promoting alpha brain wave activity, the brain state associated with calm, focused attention. It's why a cup of green tea feels different from a cup of coffee.
2.Supports neurotransmitter activity.
L-theanine plays a role in supporting GABA, dopamine, and serotonin, the neurotransmitters that influence calm, mood, and motivation.
3.Counterbalances stimulants.
L-theanine works in counterbalance to stimulants like caffeine. Where caffeine increases alertness, L-theanine supports focused attention without the jittery edge.
4.Supports a calm stress response.
L-theanine has been studied for its role in supporting a calm response to stress. It's part of why green tea has long been associated with focused calm rather than the buzz of stronger caffeinated drinks.
Summarized from published research on L-theanine and cognitive performance.
The Pairing
L-Theanine + Caffeine
L-Theanine to Caffeine
L-theanine on its own supports a calm, focused state. But it's most studied when paired with caffeine.
At a 2:1 ratio (L-theanine to caffeine), the combination has been studied for faster reaction times, better attention accuracy, and a focus state that's both alert and calm.
DayShift uses exactly that ratio: 240 mg of L-theanine, 120 mg of caffeine, every packet.
Why We Use It
L-theanine is the counterbalance. Caffeine alone produces alertness but can also produce jitters and energy spikes. L-theanine supports a cleaner focus from the caffeine and a more sustained energy curve.
240 mg per packet is calibrated for that role: paired at exactly 2:1 with caffeine, the ratio used in the published research on cognitive performance.
Key Focus Areas
- Calm Focus
- Sustained Attention
- Stress Support
How Our Dose Stacks Up.
A clinically studied dose, delivered daily.
DayShift uses the 2:1 ratio with caffeine, the dose studied for cognitive performance.
Want to Learn More?
Explore the peer-reviewed research on L-theanine and the caffeine pairing.
Nobre et al. 50 mg of L-theanine significantly increased alpha brain wave activity in healthy participants, the EEG-measured state associated with relaxed alertness.
Read on PubMed →Haskell et al. RCT comparing L-theanine alone, caffeine alone, and the combination. The combined group showed faster reaction time and improved sentence verification accuracy versus caffeine alone.
Read on PubMed →Kimura et al. Participants given L-theanine before a mental arithmetic stress task showed reduced heart rate and salivary IgA stress markers, linked to attenuated sympathetic nervous activation.
Read on PubMed →Make The Shift Today.
240 mg of L-theanine, 120 mg of caffeine, and clinically studied doses of six other ingredients in every packet.
Try it risk-free. Complete your first 10 servings and don't feel a difference? We'll refund you completely.
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