Natural Factors, Stress-Relax, Suntheanine L-Theanine, 100 mg
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.
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Our Verdict
Its Suntheanine form and flexible chewable dosing outweigh the generic-form products below it, but added sugar, numerous excipients and a $0.63 active-dose cost keep it behind the capsule and softgel leaders.
Score Breakdown
Pros & Cons
Pros
- •Uses the fermentation-derived, pure L-isomer Suntheanine ingredient.
- •Two tablets provide 200 mg, while each 100 mg tablet permits smaller serving increments.
- •Suitable for vegans and labeled with Isura non-GMO documentation and mass-spectrometry testing.
Cons
- •A two-tablet serving contains 3 g of added sugar plus xylitol.
- •Only 30 labeled 200 mg servings are provided, producing the list's highest cost per equal active dose.
Specifications
| L-Theanine Form | Suntheanine®; fermentation-derived, isomerically pure L-theanine |
| L-Theanine Per Serving | 200 mg |
| Serving Size | 2 chewable tablets |
| Servings Per Container | 30 |
| Caffeine Per Serving | 0 mg |
| Format | Vegan chewable tablet |
| Other Ingredients | Organic cane sugar, xylitol, stearic acid, silica, natural tropical flavor, citric acid, vegetable magnesium stearate |
| Third-Party Evidence | iHerb label lists Isura non-GMO documentation and mass-spec laboratory testing; no public current-lot COA was reviewed |
Who Is This For?
Best For
- People who prefer a chewable instead of a capsule
- Vegans wanting Suntheanine in adjustable 100 mg tablet increments
Not For
- Buyers avoiding added sugar or sugar alcohols
- Value-focused buyers comparing cost per 200 mg
Where to Buy
Appears In
Customer Reviews
Alternatives to Consider
California Gold Nutrition, L-Theanine, Featuring AlphaWave, 200 mg, 60 Veggie Capsules
California Gold Nutrition
Each vegetarian capsule contains 200 mg of branded AlphaWave L-theanine and no caffeine. The supplier specifies AlphaWave as at least 98% L-theanine, while iHerb publishes a product-specific iTested certificate, although the located report covers a 2018 lot.
Sports Research, L-Theanine, 200 mg, 60 Softgels
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.
Nature's Bounty, L-Theanine, 90 Capsules
Nature's Bounty
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.
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.