L-theanine · Capsules
L-Theanine
by Pure Encapsulations
200 mg of L-theanine per capsule, in the branded Suntheanine form, at a fixed dose. The label's serving is two capsules (400 mg), at the top of the 200 to 400 mg a day the research used. Costs more per capsule than generic L-theanine.
Best for
- Adults who want a single-ingredient L-theanine in the Suntheanine form
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.
What is in it
| Ingredient | Per serving | Dose used in research |
|---|---|---|
| L-theanine (as Suntheanine) | 400 mg (200 mg per capsule) | 200 to 400 mg per day |
Serving size: 2 capsules
What the research says
May support relaxation and a calmer response to everyday stress
Promising 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
Early 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
- Brian found no independent certification mark (such as NSF Certified for Sport) for this product.
- The brand's own testing claims have not been checked against its site yet.
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, a branded, purified form of L-theanine, named on the bottle's label
- Single ingredient, 200 mg a capsule
Cons
- Costs more per capsule than generic L-theanine
- The label's two-capsule serving is 400 mg, the top of the studied range
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.
Pure Encapsulations L-Theanine
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