--- product_id: 1864778 title: "Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count" brand: "doctor's best" price: "1392832₫" currency: VND in_stock: true reviews_count: 10 url: https://www.desertcart.vn/products/1864778-doctors-best-l-theanine-contains-suntheanine-helps-reduce-stress-sleep store_origin: VN region: Vietnam --- # 90-count bottle for 3 months of daily calm Non-GMO, vegan & gluten-free veggie capsules 150 mg Suntheanine for mental clarity Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count **Brand:** doctor's best **Price:** 1392832₫ **Availability:** ✅ In Stock ## Summary > 🧘‍♂️ Unlock calm focus—because your mind deserves the best ## Quick Answers - **What is this?** Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count by doctor's best - **How much does it cost?** 1392832₫ with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.vn](https://www.desertcart.vn/products/1864778-doctors-best-l-theanine-contains-suntheanine-helps-reduce-stress-sleep) ## Best For - doctor's best enthusiasts ## Why This Product - Trusted doctor's best brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Clean & Conscious:** Non-GMO, gluten-free, soy-free, and vegan-friendly to fit your mindful lifestyle - • **Easy Daily Ritual:** Convenient, easy-to-swallow veggie capsules designed for consistent use and optimal absorption - • **Pure Suntheanine Power:** 150 mg of clinically studied L-Theanine per capsule for focused calm without drowsiness - • **Sustained Calm, No Crash:** Promotes relaxation and stress relief while maintaining alertness—perfect for busy professionals - • **Trusted Science, Proven Results:** Backed by 35+ years of rigorous research from Doctor’s Best, a leader in quality supplements ## Overview Doctor's Best L-Theanine delivers 150 mg of patented Suntheanine per vegan capsule, supporting stress reduction, relaxation, and enhanced mental focus without drowsiness. Non-GMO, gluten-free, and soy-free, this 90-count bottle offers a clean, science-backed supplement trusted by professionals seeking balanced calm and cognitive sharpness. ## Description At Doctor’s Best, we understand that stress can be an unwelcome guest. That is why our specialized formula features a pure form of L-theanine that is renowned for promoting relaxation, managing stress, and sharpening focus for a more balanced state of mind.* ## Features - L-THEANINE SUPPLEMENT: Each capsule provides 150 mg of Suntheanine, a pure form of L-theanine (the amino acid found in green tea). It is known for its supportive role in relaxation & mental clarity - TENSION & STRESS SUPPORT: L-theanine helps encourage a relaxed state without drowsiness, supporting a sense of calm during everyday stress while still allowing for alertness and focus - PROMOTES FOCUS: This supplement supports cognitive performance by promoting attention and mental sharpness, beneficial for work, study, or other focus-driven activities - 150 MG VEGGIE CAPS: Doctor's Best L-Theanine comes in convenient, easy-to-swallow veggie capsules. This formula is Non-GMO, gluten free, soy free, and vegan-friendly, fitting a variety of lifestyles - DOCTOR'S BEST: Good nutrition starts with sound science. For over 35 years, we have been dedicated to providing only thoroughly researched, rigorously tested, and clinically-approved supplements ## Technical Specifications | Specification | Value | |---------------|-------| | Asin | B001OXTGVG | | Best Sellers Rank | #1,165 in Sales & Deals | | Date First Available | September 1, 2009 | | Department | Health and Beauty>Health and Wellness | | Is Discontinued By Manufacturer | No | | Item Model Number | DRB-00197 | | Manufacturer | Doctor's Best | | Product Dimensions | 2.13 x 2.13 x 3.69 inches; 2.12 ounces | ## Product Details - **Age Range (Description):** Adult - **Brand:** Doctor's BEST - **Diet Type:** Gluten Free - **Flavor:** Unflavored - **Item Form:** Capsule - **Item Weight:** 0.06 Kilograms - **Item dimensions L x W x H:** 2.13 x 2.13 x 3.69 inches - **Primary Supplement Type:** multivitamin - **Product Benefits:** Relaxation - **Unit Count:** 90 Count ## Images ![Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count - Image 1](https://m.media-amazon.com/images/I/719zn9vom2L.jpg) ## Questions & Answers **Q: How do you choose between their Suntheanine and their 5-HTP? Both seem to do the same thing.** A: 5-HTP is the tryptophan-based intermediate to serotonin which most antidepressants work to increase or support. It's more specifically targets serotonin, needed for a balanced mood. Suntheanine, a patented and advanced form of L-Theanine, has a broader range of psychotherapeutic and neuro- cognitive benefits than does 5-HTP. It works as an anti-anxiety from multiple paths. 1) It supports the levels of gaba to calm the brain 2)It blocks glutamate receptors in the brain from receiving an excitatory neurotrans-mitter 3) It induces Alpha Waves in the brain. Additionally, as a small molecule powerful antioxidant, it crosses the blood brain barrier to reach neurons directly where it fight oxidation in them. This gives it the ability to fight or offer benefit against a wide range of age-related neuro-cognitive conditions such as memory loss, learning impairments, attention deficits, dementia, Alzheimer's etc. **Q: Has anyone taken Suntheanine by opening the capsules and adding to liquid? If so, how is the taste?** A: My daughter, after first asking the doctor if it was safe, decided to try it with her Autistic child. Since she can't swallow pills, my daughter opens the capsule and places it into applesauce or a similar food. It still seems effective and my grandchild didn't seem to mind or notice any bad taste. So, I assume if it can be placed in food, it should be fine to also place it in a liquid. I hope this has helped you with your questions. **Q: I see some theanine comes from China. I would prefer one produced in the USA. Does any ingrediant in this come from China?** A: What is the country of origin for Doctor's Best products?Doctor's Best products are quality tested and manufactured in the United States using highly qualified cGMP manufacturers and raw material ingredients. Doctor's Best sources raw materials from around the world and ingredients are subject to the intense testing and verification regardless of geography of origin.- See more at: http://www.drbvitamins.com/products/suntheanine-l-theanine-150mg/drb-00197#sthash.wAlbJQD6.dpuf **Q: Does this contain caffiene?** A: It doesn't state anywhere on the bottle that it contains caffeine. I'm not sure, you will have to investigate further. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Very good NON-hormonal OTC supplement that promotes relaxation at bedtime. *by on Reviewed in the United States December 28, 2025* I find this particular formulation of L-Theanine to be a very good adjunct to help me fall asleep and stay asleep. This formula by the Doctor's Best brand has "Suntheanine," which is a patented form of the amino acid L-Theanine known to promote relaxation. I've taken this formula steadily for about a year at bedtime with only good results as part of an overall sleep hygiene routine that also includes listening to a Calm sleep story on the app in my phone, next to my bed.Also why I like this particular formulation is that it has just 150 mg of the Suntheanine/L-theanine in it, which is less than most other formulas on the market. IMO, less of something often translates to "more." I don't know how long it stays in the system, but probably not for very long, because I wake up normally, with no leftover drowsiness.Another reason why I like this supplement is because it's NON-hormonal. Some folks use melatonin to promote sleep, but I've always avoided that, since melatonin is a hormone, and from what I understand, it's not meant to be used long-term.For me, this has performed as a safe and effective over-the-counter sleep aid. As of December 2025, it was still reasonably priced. ### ⭐⭐⭐⭐⭐ Natural alternative to anxiety medication *by on Reviewed in the United States March 20, 2013* This is such a great natural alternative to anxiety medication. It takes the edge off of stress caused by everyday living. It helps you to go about your day without a lot of the worries associated with our daily lives. I like taking it along with Calms Forte by Hylands.. Taken together definitely calm you without making you sleepy. I always have these two products on hand. After I stopped taking anxiety meds from the doctor I went through withdrawal and these two products were a God send for the side effects the chemical withdrawals I was going through due to Klonopin and Xanax. I really don't know what I would've done without them. A Naturopath recommended them to help with withdrawal and then to help with any anxiety I may have in the future. Awesome product. Helped me immediately. Here is some more helpful information about Suntheanine. I found Doctors Best to work the best, as I have tried other brands.Mental AlertnessClinical trials suggest that an amount of between 50 to 200 mg of Suntheanine stimulates alpha waves (brain activity), which are identified with a calm but alert mental state. Because Suntheanine is absorbed through the large intestine and transported directly to the brain, it stimulates alpha brain waves, which are "emitted" once we have finished an activity and have stopped to rest. Suntheanine encourages the activity of neurotransmitters, which help regulate attention, learning, mood, memory, body temperature, appetite and sleep. All of these are enhanced by the presence of Suntheanine in our bodies. And the substance also may heighten our mental acuity and support our immune system.Stress ReliefSuntheanine is believed to promote stress relief while providing calm and relaxation similar to deep meditation. A completely natural substance, Suntheanine does not produce the undesirable side effects produced by synthetic drugs such as fatigue and drowsiness.Read more: Suntheanine Benefits | eHow.com [...] ### ⭐⭐⭐⭐⭐ Great price on L-Theanine! *by on Reviewed in the United States January 20, 2014* L-Theanine was first recommended to us by a psychiatrist for our younger son when he was in 4th grade and developed a tic due to stress of a teacher in a new school. It didn't do anything for the tic, but our older son took some one day, and really felt great! He's in high school and had been feeling pretty stressed. He said it helped him feel calmer and less anxious while not losing any focus.The good thing is L-Theanine is an amino acid; it's found in green tea. It can cross the blood brain barrier and has a positive effect on alpha-brain waves; it has a relaxing effect, reducing physical and mental stress, boosts mood and cognition. It also acts in concert with caffeine to boost cognitive performance. L-Theanine has been tested on small groups of people with significant sleep disorders, and while it's not overly sedating, it does affect alpha waves and tends to be relaxing. It helps those people with sleep, as it does with anxiety.My husband and I recently added it to our Amazon subscription list of supplements when we read an article in Life Extention Foundation's December 2013 magazine about supplements one should consider adding when facing the flu. It was incredibly timely! No sooner did I get the magazine, read it, stock up and get enough for all the kids, than I got socked with a sinus infection/flu. I have never before gone without a course of antibiotics, but this time really wanted to make the effort. I hunkered down with my supplements - L-Theanine included, ate cooked mushrooms (natural anti-viral) several times, as well as maintaining good hydration, and stayed in bed. I finally made it through my very first painful sinus infection/flu w/o antibiotics!So, yes, I heartily recommend L-Theanine! I'll keep buying it for myself, my husband, and our kids! ## Frequently Bought Together - Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count - Doctors BEST High Absorption Magnesium Lysinate Glycinate 100% Chelated, Muscle Relaxation & Sleep Support, Non-GMO, Gluten Free, Soy Free, Vegan, 100% Chelated 240 Tablets - Nordic Naturals Ultimate Omega, Lemon Flavor - 90 Soft Gels - 1280 mg Omega-3 - High-Potency Omega-3 Fish Oil Supplement with EPA & DHA - Promotes Brain & Heart Health - Non-GMO - 45 Servings --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.vn/products/1864778-doctors-best-l-theanine-contains-suntheanine-helps-reduce-stress-sleep](https://www.desertcart.vn/products/1864778-doctors-best-l-theanine-contains-suntheanine-helps-reduce-stress-sleep) --- *Product available on Desertcart Vietnam* *Store origin: VN* *Last updated: 2026-06-05*