BioStacks
Natural Factors

Stress-Relax, Suntheanine, L-Theanine, 100 mg, 60 Chewable Tablets

2 Tablets × 1.5/day

iHerbAmazon

Best for

Stress & MoodSleep

Ingredients (1)

Suntheanine® L-Theanine

100%

Dose/day

300 mg

Target

100–250 mg

Form

Premium

Other Ingredients (7)

SucroseSweetener

Added sugars and high glycemic load; dental caries risk

XylitolSweetener

A FODMAP sugar alcohol that can cause GI distress (bloating, gas, diarrhea) at moderate doses (>10-20g/day), though supplement amounts are typically small. Extremely toxic to dogs — households with pets should store securely.

Magnesium StearateLubricant

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

Natural Tropical FlavorFlavor

A proprietary natural flavoring blend imparting tropical-fruit taste

Silicon DioxideAnti-caking

Fine silica powder used to prevent clumping

Citric AcidAcidulant

Natural acid derived from citrus fruits

Stearic AcidLubricant

Saturated fatty acid used as tablet lubricant

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
Label directs 1.5 servings — keep one for the evening

On the label

Chew 1-2 tablets 3 times per day or as directed by a health professional.

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

Price Check

$18.87

$10$20$50

Cheaper than 70% of 101 theanine supplements

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Sources & Scoring

Nutrient data (RDA, UL, and safety thresholds) sourced from the NIH Office of Dietary Supplements and the 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. studied 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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