Doctor Life L-Theanine 200 mg — 120 capsules

Pack size: 120 capsules

ShopAmino acids and proteins

Doctor Life

L-Theanine 200 mg

Supports relaxation and stress management

41,99 zł

A calmer daily routine during demanding periods
Supports a thoughtful approach to managing stress
Designed for workdays and evening wind-down routines

Overview

Calm readiness for demanding days and quieter evenings. L-Theanine 200 mg is a focused formula for adults managing tension, intensive mental work, or the need to unwind at night.

At the heart of the formula / L-Theanine 200 mg

Thoughtful support. Clear purpose.

01A calmer daily routine during demanding periods
02Supports a thoughtful approach to managing stress
03Designed for workdays and evening wind-down routines
04200 mg in each capsule
05A flexible schedule of one or two servings daily
06Up to four months of use per bottle

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L-Theanine 200 mg

Made for your daily routine.

Each capsule provides 200 mg of L-theanine, an amount used in several human studies. The recommended daily serving is one or two capsules.

The single-ingredient formula contains no caffeine or other active ingredients. Its pullulan capsule is suitable for vegans and vegetarians. Each bottle provides a 60- to 120-day supply, depending on the daily serving.

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L-Theanine 200 mg

What is L-theanine?

L-theanine is an amino acid naturally found in tea leaves. Researchers study it in relation to relaxation, attention, stress responses, and sleep. It is not a conventional stimulant or sleep medication.

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L-Theanine 200 mg

What research informs L-Theanine 200 mg?

Human trials have explored L-theanine in relation to stress, cognition, and sleep, including studies using 200 mg daily. Some reported changes in selected measures, and reviews have examined perceived sleep quality. Findings vary and do not establish that this finished product will produce a particular result.

Ingredients / Doctor Life

Every ingredient. Clearly explained.

Each ingredient, its form and quantity — in one place.

Ingredient amounts for the servings shown in the table.
Ingredient	1 capsule
L-theanine	200 mg

*NRV: Nutrient Reference Value

Full ingredient list

L-theanine, capsule shell (bulking agent: pullulan).

How to use

Part of your daily rhythm.

How to use

Recommended daily serving and directions: take 1 capsule once or twice daily as needed, preferably on an empty stomach.

Important information

Do not exceed the recommended daily serving. Food supplements should not replace a varied diet. A balanced diet and a healthy lifestyle are recommended. Store at room temperature, away from sunlight and out of reach of young children.

Science & sources

Understand the formula.

These selected publications explore L-theanine in relation to stress, cognitive performance, and sleep quality.

These publications concern the studied ingredients or formulas. They do not all evaluate the finished Doctor Life product, and research results do not guarantee individual outcomes.

01Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial

S. Hidese, M. Ota, C. Wakabayashi et al.

Nutrients (2019), 11(10), 2362. DOI: 10.3390/nu11102362; PMID: 31623400.

In a randomized, double-blind study, healthy adults took 200 mg of L-theanine daily for four weeks. Favorable changes were observed in selected measures of stress, sleep, and cognitive function.

Read publication ↗

02L-Theanine reduces psychological and physiological stress responses

K. Kimura, M. Ozeki, L. R. Juneja, H. Ohira

Biological Psychology (2007), 74(1), 39–45. DOI: 10.1016/j.biopsycho.2005.08.003; PMID: 16930802.

The study examined participants' responses to an acutely stressful task. The findings contributed to interest in L-theanine and responses to demanding situations.

Read publication ↗

03The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis

A. Bulman, A. McArthur, N. Naumovski et al.

Sleep Medicine Reviews (2025), 81, 102076. DOI: 10.1016/j.smrv.2025.102076; PMID: 40056718.

This systematic review and meta-analysis included 19 publications on L-theanine and sleep. The findings indicated improvements in selected self-reported measures, including sleep quality and time to fall asleep.

Read publication ↗

FAQ / L-Theanine 200 mg

Good questions. Clear answers.

Talk to us ↗

Will L-theanine make me sleepy during the day?

L-theanine is not a conventional sleep medicine, but individual responses can differ. Try your first serving when you can assess how it affects you.

Why include 200 mg per capsule?

The 200 mg amount is used in several L-theanine studies. One capsule provides that serving, and the directions allow a second capsule during the day if needed.

Does L-theanine have to be combined with caffeine?

No. This product provides L-theanine without caffeine. Studies of the combination should not automatically be applied to a caffeine-free formula.

Should I take it in the morning or evening?

Take one capsule once or twice daily as needed, preferably on an empty stomach. Choose the timing according to your routine and individual response.

How many days does a bottle provide?

Each bottle contains 120 capsules: a 120-day supply at one capsule daily or a 60-day supply at two.

How does this differ from a multicomponent stress supplement?

It focuses on one active ingredient, with a clearly stated L-theanine amount. The plant-based pullulan capsule is suitable for vegans and vegetarians.

Can I combine L-theanine with medication or other supplements?

If you take medication, have a chronic condition, or use several supplements, ask your doctor or pharmacist to review the combination.

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