Nature's Bounty, L-Theanine, 90 Capsules
Each vegetarian capsule contains 200 mg of generic-source L-theanine and no caffeine; the only listed inactive material is the hypromellose-and-water capsule. NutraBio states that finished products receive third-party verification and offers lot-specific certificates, but the label does not identify a branded ingredient or publish an L-isomer purity specification.
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Our Verdict
Its testing process, clean label and low cost per 200 mg beat the fifth-ranked product on the heavier testing and transparency criteria, but the undisclosed source and stereoisomer specification limit its form score.
Score Breakdown
Pros & Cons
Pros
- •Provides 200 mg in one capsule and 90 servings per bottle.
- •The label lists no filler beyond the vegetarian capsule shell.
- •NutraBio provides a lot-number process for retrieving certificates of analysis.
Cons
- •No branded source, fermentation method or stereoisomer-purity specification appears on the label.
- •A current product-specific laboratory report could not be reviewed without a bottle lot number.
Specifications
| L-Theanine Form | Generic-source L-theanine; stereoisomer purity and manufacturing method not disclosed on label |
| L-Theanine Per Serving | 200 mg |
| Serving Size | 1 vegetable capsule |
| Servings Per Container | 90 |
| Caffeine Per Serving | 0 mg |
| Format | Vegetarian capsule |
| Other Ingredients | Hypromellose and water capsule only |
| Third-Party Evidence | Brand states finished-product third-party verification and lot-specific COA access; no current-lot report was reviewed |
Who Is This For?
Best For
- Buyers prioritizing minimal inactive ingredients
- People willing to retrieve and inspect the certificate for their bottle's lot
Not For
- Buyers requiring Suntheanine or AlphaWave by name
- Buyers requiring a publicly viewable certificate before purchase
Where to Buy
Appears In
Customer Reviews
Alternatives to Consider
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Sports Research
One softgel contains 200 mg of Suntheanine, Taiyo's fermentation-derived, isomerically pure L-theanine ingredient, with no caffeine. The product is publicly listed as IGEN Certified for non-GMO criteria and its label states third-party testing with lot-number lookup.
Natural Factors, Stress-Relax, Suntheanine L-Theanine, 100 mg
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The labeled serving is two vegan chewable tablets supplying 200 mg of fermentation-derived Suntheanine without caffeine. The label fully discloses 3 g of added sugar per serving, xylitol and the remaining tablet ingredients.
Doctor's Best, L-Theanine, AlphaWave, 200 mg, 60 Veggie Caps
Doctor's Best
One vegan capsule supplies 200 mg of branded AlphaWave L-theanine with no caffeine. AlphaWave's supplier specifies at least 98% L-theanine, but no USP, NSF, Informed Sport or published Doctor's Best product-specific certificate was located.