L-theanine · Capsules
Theanine
200 mg of Suntheanine per capsule, the branded form used in most human L-theanine research, at a fixed dose. Costs more per capsule than generic L-theanine.
Best for
- Adults who want a single, well-documented form of L-theanine
- Evening or pre-stress dosing at a fixed 200 mg
Not for
- Buyers who want the lowest cost per milligram (generic L-theanine capsules are cheaper)
Where it fits in the program
L-theanine
- Primary role
- Calm and relaxation
- Contribution to healthy aging
- May support relaxation, managing everyday stress and winding down.
The rest of the program
Each supplement covers a different job. You only need the ones that match your goals.
What is in it
| Ingredient | Per serving | Dose used in research |
|---|---|---|
| L-theanine (as Suntheanine) | 200 mg | 200 to 400 mg per day |
Serving size: 1 capsule
What the research says
May support relaxation and a calmer response to everyday stress
verifiedPromising evidenceA systematic review of 9 randomized controlled trials found that 200 to 400 mg per day of L-theanine may help lower stress and anxiety symptoms in people under stressful conditions, though the authors called for larger, longer trials before it is relied on as an established therapy.
May increase alpha brain-wave activity associated with relaxed wakefulness
verifiedEarly evidenceA crossover trial measuring brain activity directly found greater resting alpha-wave activity 2 hours after an L-theanine drink than after placebo, but only in people who ran higher in trait anxiety to start with.
What the grades mean is explained in how we choose.
Quality and testing
- The brand states this product is third-party tested to verify label accuracy and to screen for heavy metals, pesticides and microorganisms.
- Not NSF Certified for Sport.
See what the brand itself claims about this ingredient, and how Brian grades each claim
Safety
- Generally well tolerated. Talk to your doctor before combining with blood pressure medication, since it may add to a blood-pressure-lowering effect.
- Interactions with sedatives have not been ruled out; check with a pharmacist if you take one.
Pros and cons
Pros
- Suntheanine, the branded form used in most human research on L-theanine
- Single ingredient, fixed 200 mg dose
- Third-party tested for contaminants
Cons
- Costs more per capsule than generic L-theanine
- Not NSF Certified for Sport
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. This page is general information, not medical advice. Talk to your doctor before starting a supplement, especially if you are pregnant, have a medical condition or take medication.
Theanine
$68.00 · $0.76/serving