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Doctors Best Sports Research L-Theanine featuring Suntheanine® (200mg) bottle
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Doctors Best Sports Research L-Theanine featuring Suntheanine® (200mg) Review

Sports Research L-Theanine features the premium, patented ingredient Suntheanine®. Formulated with Virgin Coconut Oil, this supplement is designed to support a state of relaxation and focused attention without drowsiness.

Product Focus: Adrenal SupportAlso graded for:Stress and CalmAlso covers:BrainHormones
Tier ⓘ
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Members see this product's tier and why. Tiers run from 1, the strongest evidence, to 5. How we grade →
Evidence ⓘ
Members
How strongly the evidence says this product works: human studies count most, then real reviews, then our biohacker panel.
Positive Reviews
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Biohacker Mentions
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Cost per month
$10
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Study, Trial or Testing Result Summary

MembersHuman studies

This product gives 200 milligrams of L-theanine per serving, the same dose used in of the studies, so it is at a studied dose. For the stress hormone system, the evidence is . …

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Review Totals and Summary

Members15,183 reviews
15,183 reviews · Amazon 14,731 · Walmart 441 · Sportsresearch 6 · Target 5

Sports Research L-Theanine featuring Suntheanine® (200mg) appears to have won over a of users, with reviews reflecting with the product’s calming and perceived support for relaxation or mood. Across retailer platforms like Amazon, Walmart, and a handful of reviews on other sites, people commonly mention that the product them feel at , anxious, or able to wind down easily, particularly in stressful situations or before bedtime. …

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Biohacker Summary

MembersWhat our biohacker panel says

Our biohacker panel has discussed this product yet.

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RAL Summary

MembersThe tier and why

L-theanine is present at the 200 milligram dose studied, a pooled analysis shows a but with some single-dose studies stress hormone responses, and of over 15,000 reviews are .

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More Details

MembersBody systems · Combine with · Possible side effects

Body systems: Nervous system, Endocrine system. Combine with and possible side are for members.

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Supplement Facts

L-Theanine 200 mg
Supplement Facts
Serving Size 1 Softgel
Servings Per Container 60
Amount Per Serving% Daily Value
L-Theanine (Suntheanine®)200 mg†
† Daily Value not established.

Other ingredients: Organic virgin coconut oil, softgel capsule (gelatin, vegetable glycerin, purified water), organic beeswax. CONTAINS: Tree nuts (coconut).

Directions: 1 softgel daily

Label source: Amazon · Report a label change

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Our articles on this subject

Graded October 23, 2026 by the Reverse Age Lab evidence engine, from human studies, real reviews and our biohacker panel. How we grade. Is this medical advice? No. Rala organizes the published evidence; go over any change with your doctor, especially if you take meds.