If you're looking for calm focus without drowsiness, this delivers exactly the dose the research supports. **L-Theanine** at 200mg per capsule matches the most studied single dose for promoting relaxation and reducing stress-related mental noise — you're right in the sweet spot of the 100–250mg clinical range.

The formula also includes 100mg of **Inositol**, but that's worth context: clinical studies on inositol for mood and stress use 2,000–4,000mg per day. At 100mg, you're getting about 5% of the minimum studied dose, so its contribution here is negligible.

This is really a theanine product with a token amount of inositol. For stress relief and focus, the theanine dose alone justifies the capsule. If you're specifically interested in inositol's benefits, you'd need a dedicated supplement at a much higher dose.

BioStacks
NOW

Double Strength L-Theanine 200 mg

1 Capsule · 120 servings · $0.20/serving

iHerbAmazon

Best for

Stress & Mood

Ingredients (2)

L-Theanine

100%

Dose

200 mg

Target

100–250 mg

Form

—

Inositol

5%

Dose

100 mg

Target

2000–4000 mg

Form

—

Other Ingredients (3)

Silicon DioxideAnti-caking

Fine silica powder used to prevent clumping

HypromelloseCapsule

Plant-derived capsule material from cellulose

Stearic AcidLubricant

Saturated fatty acid used as tablet lubricant

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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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