Suntheanine L-Theanine gives a calm, focused clarity through the patented Suntheanine form, helping you unwind while staying alert even on busy days. The key active ingredient Suntheanine helps relaxation without heaviness, and Doctor's Best backs this with science-based nutrition and a pledge to clear ingredient quality. That means steady everyday support for focus and calm.

Available Sizes & Variants:

90 capsules L-Theanine supplement - everyday daily supply for ongoing support

Benefits & Features:

• Promotes relaxed focus without feeling drowsy.
• Supports calm alertness during demanding tasks by helping balance mood and tension, so you can stay productive without the jitters that come with stress.
• Key active ingredient Suntheanine provides a purified, branded form of L-theanine.
• Manufactured as non-GMO, vegan, gluten-free and soy-free to suit most diets.
• Simple daily capsule fits easily into a busy routine without heavy effects.

Doctor’s Best champions Science-Based Nutrition, delivering quality you can feel. Suntheanine is the premier, patented form of L-theanine, produced by a trusted fermentation process that mirrors the natural compound in green tea. The result is a pure, predictable relaxation that supports calm focus without heaviness. Research suggests L-theanine can help ease everyday stress and sharpen attention, with alpha brain waves rising as a sign of relaxed alertness. The brand’s transparency and vegan, non-GMO approach underline a level of quality that stands out in l theanine supplements.

(other) Microcrystalline cellulose, modified cellulose (vegetarian capsule)

• GTIN: 753950001978
• Manufacturer: Doctor's Best
• Categories: Doctor's BestL-TheanineNew ArrivalsNootropicsSleep & Relaxation SupplementsStress Relief & Calming SupplementsSupplements for Anxiety
• Best buy: 6 - 24 months+

United Kingdom Shipping:

Orders placed by 2pm (Monday to Friday) are dispatched the same day. Orders placed after 2pm will be dispatched the next working day.

Free shipping on orders over £50 to the UK.

Returns: Our products are meant to make you feel healthy and at your best. If you need to return your item, you can do so free of charge within 30 days in the same original and unopened packaging. Subject to T&C's.

Take 1 capsule daily on an empty stomach, or as advised. Take one capsule per day.

Please consult the product packaging for accurate instructions on how to use the product.

The Active Ingredient Is: L-Theanine (Suntheanine)

L-Theanine is an amino acid often found in tea and used as a dietary ingredient to support normal brain function and mood balance.

This Suntheanine form is a purified, branded variant of L-Theanine produced by fermentation, recognised for its high purity and reliability and closely mirroring the natural L-Theanine found in green tea.

What Does L-Theanine Do?

L-Theanine helps foster a relaxed yet focused state and has been linked to reduced perceived stress and improved cognitive performance in healthy adults, with research noting relaxation without sedation.

Evidence suggests L-Theanine can influence brain activity linked with calm focus, supporting normal nervous system function. Dr. Yoto of Osaka University found that L-Theanine increases alpha brain wave activity, supporting a calm yet alert mental state.

This product isn't intended to diagnose, treat, cure, or prevent any disease.

We picked Doctor's Best Suntheanine L-Theanine as our collaborator because the brand shows a genuine commitment to science-led nutrition and clear ingredient quality. Doctor's Best teams up with Suntheanine, a top patented form of L-theanine, underscoring their focus on delivering a pure, well-described active component backed by branded sourcing. The maker's way to product integrity lines up with Welzo’s emphasis on reliability and traceability, helping our goal to offer constantly high standards for customers.

When it comes to product-specific fit, Suntheanine provides a single, top-quality active ingredient in a vegan, non-GMO, gluten-free formulation, which lines up with our expectations for clean, clearly defined supplements. This brand’s clear commitment to quality and its use of a trusted branded ingredient helps us keep consistency across batches, a key factor for a product meant to support calm focus and stress control without extra additives. Our team looked at Doctor's Best for manufacturing philosophy, sourcing transparency, and alignment with our quality expectations, and we feel good about this partnership. For customers, this means we have a trusted supplier with strict internal standards, verified by Welzo's healthcare team and our quality controls.