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L-Theanine Ingredient Notes
L-Theanine benefits, side effects, cautions, and related iHerb product search in one page.
L-theanine is an amino acid from tea often searched with calm focus, caffeine pairing, and relaxation keywords.
Community experiences
Selected positive personal experiences from external communities, edited and summarized. These accounts do not establish effectiveness.
A contributor experiencing anxiety wrote that about 20 to 30 minutes after taking L-theanine, they felt calmer and more interested in activities they wanted to do. They had been receiving counseling for about two years and also reported a mild to moderate headache after taking it. In a follow-up after four or five uses, they said it still helped, though not as strongly as at first, and acknowledged that expectations might also have played a part.
Experience shared by external community contributor A
This page is for general reference only and is not medical advice, diagnosis, treatment, or prescription. Ask a qualified professional if you need medical advice or diagnosis.
Questions before taking a supplement
Sources checked:
What has been studied about L-theanine with caffeine?
A randomized trial found improvement on a task-switching attention test, but not all attention or alertness measures. This does not establish that theanine cancels caffeine side effects. Count caffeine from drinks too and check combination warnings on the label.
Source: Einother et al. (2010): L-theanine and caffeine trialIs a studied L-theanine dose my recommended daily amount?
A research dose is not a personal recommendation. One trial used 200 mg daily for four weeks in 30 adults; it does not establish a universal dose or long-term safety limit. Check daily product directions and your health circumstances.
Source: Hidese et al. (2019): L-theanine trialWhat is L-Theanine?
L-theanine is an amino acid found in tea. It is different from caffeine, although tea and some supplements contain both.
On Supplecipe, you can search iHerb products that mention L-Theanine and compare single-ingredient products against broader supplement blends.
Why people search L-Theanine
- People often compare standalone theanine with caffeine-theanine blends.
- Timing and dose are common discussion points.
- It is frequently paired with magnesium or melatonin in evening routines.
Forms and other names
L-Theanine may also appear on labels as Theanine. Searching by both the common name and label name can reveal more products.
Related ingredients
Related reading, not a recommendation to combine supplements.
Side effects and cautions
- It may cause drowsiness in some people.
- It is not a treatment for anxiety or sleep disorders.
How to compare iHerb products
- Check the active ingredient amount per serving, not only the front-label claim.
- Look for form, serving size, extra ingredients, allergens, and whether the product is a single ingredient or a blend.
- Compare brand, price per serving, ingredient form, and single-ingredient versus complex products.
- Use the search button below to compare iHerb products that mention this ingredient.
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