All Supplements
L-Theanine vs Selenium
Side-by-side comparison — benefits, dosage, forms, and research.
Feature
L-Theanine
Selenium
Typical Dosage
100-200mg daily
55–200 mcg daily
Best Form
L-Theanine (Suntheanine)
Selenomethionine
Key Benefits
5
5
Evidence Rating
★★★★
★★★★
Best Time
With caffeine for focus, or evening for relaxation
With meals to enhance absorption; consistent daily timing
L-Theanine Benefits
✓Calm focus without sedation
✓Reduces caffeine jitters when combined
✓Promotes alpha brain waves (relaxed alertness)
✓May improve sleep quality
✓Anxiety reduction
Selenium Benefits
✓Antioxidant protection through selenoprotein synthesis
✓Thyroid hormone metabolism and immune function
✓Reduced inflammation and oxidative stress
✓Male fertility and sperm motility support
✓Potential cognitive and cardiovascular health support
Can You Take Both Together?
In most cases, L-Theanine and Selenium can be taken together safely. However, always check the interactions section of each supplement and consult a healthcare professional if you take medication.
Which Should You Choose?
Choose L-Theanine if your primary goal is: calm focus without sedation. Choose Selenium if your primary goal is: antioxidant protection through selenoprotein synthesis. Many people take both as they target different aspects of health.
Disclaimer: This comparison is for educational purposes only. Always consult a healthcare professional before starting any supplement.