Jarrow Formulas Extra Strength L Theanine 200mg Dietary Supplement that Promotes Relaxation, Supplement for Relaxation Support, 60 Veggie Capsules, 60 Day Supply
$0.35/serving
Price verified Apr 22, 2026
Not evaluated by the FDA · Individual results may vary · Consult a healthcare provider before use
Our verdict
200mg Suntheanine per capsule of Suntheanine L-Theanine per vegetarian capsule from Jarrow Formulas. Best for pure Suntheanine in a clean vegetarian capsule.
Why we recommend this
Uses patented Suntheanine — enzymatically produced to guarantee 100% pure L-isomer theanine. Delivers the most commonly studied 200mg dose in a single capsule. Jarrow Formulas is known for science-backed formulations. Over 15,000 Amazon reviews with a 4.5-star average.
Check for interactions
Already taking other supplements or prescription medications? Add them below to check for documented interactions, severity, and clinical guidance.
Our database currently documents 137+ supplement and drug-category interaction pairs. Combinations not flagged here may still interact — always consult your healthcare provider before combining supplements, especially with prescription medications.
What to watch out for
Standard capsule (no fast-dissolve option). Contains magnesium stearate. Not NSF or USP verified.
Dose & form
- Serving
- 200mg Suntheanine per capsule
- Form
- Vegetarian Capsule
- Clinical range
- 100-200 mg daily
- Dose adequacy
- Therapeutic
- Supply
- 60 servings · $0.35/serving
- UPC
- 764442382734
Who it's best for
Pure Suntheanine in a clean vegetarian capsule
Who should skip it
Athletes requiring NSF Certified for Sport verification
Pros
- Patented Suntheanine (100% L-isomer)
- Clinical 200mg dose per capsule
- Science-backed brand
- Good value ($0.14/serving)
Cons
- Contains magnesium stearate
- Not NSF or USP verified
- Standard capsule only
What customers say
4.6★ across 2,445 Amazon reviews. The most common questions from shoppers: re any potential interactions with medications, re any side effects from long-term use, and cause any digestive issues or side effects. Full answers in the FAQ below.
Frequently Asked Questions
What is the clinical dose for Suntheanine L-Theanine?
What is the clinical dose for Suntheanine L-Theanine?
Clinical trials typically use 100-200 mg daily. Jarrow Formulas Theanine 200mg delivers 200mg Suntheanine per capsule, which we classify as Therapeutic relative to that range.
How does Jarrow Formulas Theanine 200mg compare to similar Vegetarian Capsule?
How does Jarrow Formulas Theanine 200mg compare to similar Vegetarian Capsule?
See the "Also consider" section below for two alternatives. Choose based on form preference (Vegetarian Capsule vs alternatives), dose adequacy, and third-party testing.
Is Jarrow Formulas Theanine 200mg third-party tested?
Is Jarrow Formulas Theanine 200mg third-party tested?
Yes — Third-Party Tested. Third-party testing verifies ingredient identity and label accuracy.
Does this work with Amazon Subscribe & Save?
Does this work with Amazon Subscribe & Save?
Yes — Amazon Subscribe & Save is available for this product. Enrolling locks in a recurring delivery at a reduced per-unit price.
Are there any potential interactions with medications?
Are there any potential interactions with medications?
Jarrow Formulas Theanine 200mg may enhance the effects of sedative medications and blood pressure drugs. L-theanine promotes relaxation, so combining with benzodiazepines or sleep medications may increase sedation. Consult your doctor if taking any CNS-active medications.
Are there any side effects from long-term use?
Are there any side effects from long-term use?
L-theanine has an excellent long-term safety profile. It is a natural amino acid found in green tea that has been consumed for thousands of years. Jarrow Formulas uses patented Suntheanine, which has been used in clinical trials without significant adverse effects.
Does it cause any digestive issues or side effects?
Does it cause any digestive issues or side effects?
L-theanine is exceptionally well-tolerated with very few reported side effects. It does not cause drowsiness, dependency, or tolerance. Some users report mild headache at higher doses (400mg+). Digestive issues are extremely rare at the standard 200mg dose.
Can it be taken with other supplements or vitamins?
Can it be taken with other supplements or vitamins?
Yes. L-theanine is one of the most versatile supplements for stacking. The classic combination is L-theanine + caffeine (200mg + 100mg) for focused energy. Also pairs well with magnesium for sleep, with ashwagandha for stress, and with lion's mane for cognition.
Are there any specific instructions for taking it safely?
Are there any specific instructions for taking it safely?
Take 1 capsule (200mg) as needed for calm focus or relaxation. Can be taken 1-2 times daily. For sleep support, take 200-400mg 30-60 minutes before bed. For focus, take with your morning coffee. No food requirements — works with or without meals.
How long until benefits are typically experienced?
How long until benefits are typically experienced?
L-theanine effects are felt within 30-60 minutes. Alpha brain wave activity increases within 40 minutes of ingestion. The calming effect is subtle but noticeable — reduced mental chatter and improved focus without sedation. No loading period needed.
Also consider
Part of this guide
Best L-Theanine Supplements→