BioStacks
GNC

L-Theanine 200 mg

1 Capsule · 60 servings · $0.58/serving

iHerbAmazon

Best for

Stress & Mood

Ingredients (1)

Suntheanine L-Theanine

100%

Dose

200 mg

Target

100–250 mg

Form

Premium

Other Ingredients (4)

Magnesium StearateLubricant

A salt of stearic acid used as a lubricant in tablet and capsule production

Silicon DioxideAnti-caking

Fine silica powder used to prevent clumping

GelatinCapsule

Protein derived from collagen, used in traditional capsule shells

Microcrystalline CelluloseBinder

Plant-derived cellulose used as a binder and filler in supplements

How to Take It

Best taken in the evening

Calming — common before bed, or in the morning when paired with caffeine for focus.

With or without food

On the label

As a dietary supplement, take one capsule daily.

General guidance based on the ingredients, not a substitute for the label or your doctor.

Price Check

$34.99

$10$20$50

Pricier than 70% of 118 theanine supplements

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Sources & Scoring

Nutrient data (RDA, UL, and safety thresholds) sourced from: NIH Office of Dietary Supplements and National Academies Dietary Reference Intakes (DRI).

This is not medical advice. Consult a healthcare provider before making changes to your supplement routine.

The score analyzes what's on the label: ingredient doses vs. clinical ranges, chemical forms, evidence levels, and known interactions. It does not verify label accuracy or test for contaminants — for that, look for third-party certifications like USP or NSF.

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