L-Theanine

The overall rating for l-theanine is 2 out of 3 meaning there is some evidence that this supplement does some (not all) of what it claims. Using this supplement may lead to some improvements.

1. Simple Report
2. Detailed Report
3. Overall Effectiveness Rating
4. Research Rating
5. Products Containing L-Theanine
6. Claim Ratings
7. References

• Supplement: L-Theanine
• Supplement Category: amino acid derivatives
• Number of Products Containing L-Theanine: 921
• Effectiveness Rating: 2 out of 3
• Research Rating: 20 (above 80 indicates sufficient research)
• Number of Studies: 4
• Number of Claims: 4

Overall Effectiveness Rating

The overall effectiveness rating for l-theanine is 2 out of 3. This rating means the evidence is mixed on the supplement's ability to deliver positive results. While some of the research supports its use, other evidence does not. Using this supplement may lead to positive results. Note, this effectiveness rating is for l-theanine as a whole; there are also individual ratings for the claims below.

Read more: What is the effectiveness rating?

Research Rating for L-Theanine

There are 4 studies in the database on l-theanine; the research rating is 20. A score above 80 means the effectiveness rating for this supplement is reliable. A score under 80 means there is insufficient evidence to ensure a reliable effectiveness rating. Note, this research rating is for l-theanine as a whole; there are also individual ratings for the claims below.

Read more: What is the research rating?

Products Containing L-Theanine

Products Names	Amount of L-Theanine
Winners Pre-Workout	250mg
Wild Thing	125mg
Make Her Lean MAX	50mg
Switch On Black Edition	200mg
Game On	100mg
Full list of all 921 products containing L-Theanine.

Claim Ratings

The overall ratings above are an average of the individual claim ratings below. Individual claims may have higher or lower ratings compared to the supplement's overall rating. For example, some supplements may have excellent backing for one claim, but be completely useless for another. Click on a claim below for more information.

Immune Health Claims	Effectiveness Rating	Research Rating
improve immune function
reduce frequency of the common cold

Mental Health Claims	Effectiveness Rating	Research Rating
improve cognitive ability

General Health Claims	Effectiveness Rating	Research Rating
improve sleep quality

References

Title of Study
Effects of L-Cystine and L-Theanine Supplementation on the Common Cold: A Randomized, Double-Blind, and Placebo-Controlled Trial
Effects of oral supplementation with cystine and theanine on the immune function of athletes in endurance exercise: randomized, double-blind, placebo-controlled trial
Improving mental regeneration after physical exercise
The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial