Doctor's Best L-Theanine

Supplement Facts

Serving Size: 1 Veggie Capsule

Serving Per Container: 90

Amount Per Serving

%DV

L-Theanine (Suntheanine®)

150 mg

†

The product is found useful for the following medical conditions

We conducted a randomized, double-blind, placebo-controlled trial to see how L-theanine affects sleep quality in boys aged 8 to 12 diagnosed with ADHD. Over six weeks, participants took either L-theanine or a placebo.

The results showed that 400 mg of L-theanine daily significantly improved sleep quality in these children. Since many kids with ADHD struggle with sleep issues, this suggests L-theanine could be a beneficial addition to managing ADHD symptoms. Future research with larger groups is encouraged.

9.5

Medication alternative

Most Useful Review

LIFE SAVER! Worth every penny. I have struggled with ADHD for years and now use this instead of medication. I only wish there were higher dosage capsules for serious conditions like mine.

Allergies details

They do exactly what they claim, are friendly for allergies, and I have purchased them twice. I'll likely buy again.

Pelvic Pain details

Painless menstruation

Most Useful Review

Great product! I liked it very much. I have taken it for two months on an empty stomach, one tablet prior to some physical activity. I've noticed I feel more energetic, sleep well, and best of all, my recent menstruation was painless. The pelvic pain in my lower abdomen didn't trouble me during the first few days as it usually does. I will order more. The packaging is convenient, odourless, and the tablets are small and easy to swallow. If you find this helpful, please give it a like! Thank you! Stay healthy!

Anxiety details

SCIENTIFIC SCORE

Possibly Effective

Based on 16 Researches

L-theanine supports mental health

Hidese S, Ogawa S, Ota M, Ishida I, Yasukawa Z, et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients. 2019;11. doi:10.3390/nu11102362

This study evaluated the impact of four weeks of L-theanine on stress and cognitive function in 30 healthy adults. Participants received either 200 mg of L-theanine or a placebo in a double-blind setup. We observed significant reductions in anxiety and stress symptoms, as indicated by improved scores on various measures, including sleep quality. Additionally, cognitive functions, such as verbal fluency, showed notable enhancement after L-theanine use. These findings suggest that L-theanine may be beneficial for managing stress-related issues and boosting mental performance.

9.5

Effective for anxiety

Most Useful Review

Surprisingly helpful. I have tried multiple L-Theanine brands, but Doctor's Best is the only one that works for me. Five years ago, I was advised to use L-Theanine for anxiety, but other brands did nothing for me. This year, I purchased Doctor's Best and finished the entire bottle, as it significantly improved my anxiety. I have panic disorder and recently managed a road trip by using this supplement instead of my prescribed medication, which often makes me groggy. I recommend giving it a try if you experience anxiety.

Cancer details

If you wish to feel both ENERGETIC and CALM simultaneously, you must try THEANIN! This product, especially ideal for those who experience stress like I do, offers the purest form of theanine at a dose of 150mg. I take one capsule in the morning, and it provides a sense of protection from stimuli; they persist, yet feel distant, akin to an "Olympian before the start." The great benefit of theanine is that it does not induce drowsiness or dependency. It serves as an excellent NOOTROPIC, enhancing cognitive functions, and it acts as a CARDIOPROTECTOR by regulating blood pressure and heart rate. Additionally, it collaborates with zinc to lower blood sugar levels, aids in producing the vital antioxidant glutathione that bolsters IMMUNITY and guards against CANCER DISEASES, and reduces SENSITIVITY. Theanine also pairs well with COFFEE, mitigating its adverse effects while highlighting the beneficial ones.

Depression details

SCIENTIFIC SCORE

Possibly Effective

Based on 4 Researches

L-theanine shows potential antidepressant effects

Shen M, Yang Y, Wu Y, Zhang B, Wu H, et al. L-theanine ameliorate depressive-like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic-cortical-striatal-pallidal-thalamic-circuit related brain regions. Phytother Res. 2019;33:412. doi:10.1002/ptr.6237

We examined how L-theanine, a compound found in green tea, influences depressive behaviors in a rat model. Using specific behavioral tests, such as the open-field and forced swim tests, we observed that L-theanine improved depressive-like behaviors.

Our findings indicated that it boosted levels of key neurotransmitters—serotonin, norepinephrine, and dopamine—in certain brain regions. This suggests that L-theanine could have potential antidepressant effects, possibly by interacting with these neurotransmitters in brain areas associated with mood regulation.

8.8

Stress reduced

Most Useful Review

Simply having this in my bag makes me feel better. I find it brings a sense of peace without the chemical dullness typical of other stress or depression medications. The 150mg dosage per capsule seems just right—providing a subtle calming effect and alleviating feelings of paranoia.

Sleep Apnea details

L-theanine improves sleep quality safely

Rao TP, Ozeki M, Juneja LR. In Search of a Safe Natural Sleep Aid. J Am Coll Nutr. 2015;34:436. doi:10.1080/07315724.2014.926153

We examined whether L-theanine, a natural amino acid found in tea, could improve sleep quality, especially for individuals affected by sleep apnea. Through various sleep assessments and questionnaires, we found that taking 200 mg of L-theanine before bedtime offers benefits not by putting one to sleep, but by easing anxiety.

This means users can experience better sleep without the sedative side effects commonly associated with traditional sleep aids. Importantly, L-theanine should not cause daytime drowsiness, making it a versatile option any time of the day.

Calming effects noted

Most Useful Review

I got this supplement for myself as a mother with a lot of worries and psychological stress. I was drawn to the fact that theanine calms without sedation. After taking it for a few days, I noticed superb results; I became much calmer and my sleep improved significantly. The brand also impresses me with its quality.

Autoimmune Disorder details

SCIENTIFIC SCORE

Likely Very Effective

Potential benefits for autoimmune function

Khosravi-Nezhad S, Hassanpour S, Hesaraki S. L-Theanine Improves Locomotor Function in a Model of Multiple Sclerosis Mice. Arch Razi Inst. 2023;78:195. doi:10.22092/ARI.2022.360066.2544

This study explored how L-theanine can influence the effects of cuprizone-induced multiple sclerosis in mice.

We observed that when L-theanine was administered alongside cuprizone, it improved locomotor functions and reduced damage typically caused by the disorder.

Notably, mice receiving L-theanine showed enhancements in ambulation and grip strength compared to the control group.

While the study indicates potential benefits of L-theanine, further research is necessary to fully understand its effectiveness in human autoimmune conditions.

9.5

Stress relief

Most Useful Review

This really works! I initially took these supplements for my mother to help her manage her stress. After taking one during a period of nervousness, she became remarkably calm. I have ordered another jar for my grandmother!

Heart Attack details

Calms heart palpitations

Most Useful Review

It helps calm my nerves. I suffer from sympathetic hyperactivity with heart palpitations and excessive arousal. Taking it a few hours before bed definitely helps me relax. The pill is small and easy to take.

Menopause details

I adore this product! Since I started experiencing menopause three years ago, I was so stressed that I thought I would lose my mind during the workday. I’m not usually emotional, yet I found myself in tears more than once. I researched natural products that could help with mood, and L-theanine was suggested. The positive reviews about this brand were accurate, as I was amazed at how significantly it improved my mood and stress levels. Highly recommend!

Chronic Fatigue Syndrome details

If you suffer from chronic fatigue syndrome, L-theanine Suntheanine capsules can make a significant difference. Regular use boosts activity levels and enhances nervous system function. This natural supplement relaxes without causing drowsiness and fosters a positive mood. Despite my demanding job, it helps me gradually unwind and fall asleep after long hours, avoiding addictive chemicals found in sleeping pills.

Insomnia details

SCIENTIFIC SCORE

Likely Ineffective

Based on 2 Researches

Insufficient evidence for L-theanine

Barrett JR, Tracy DK, Giaroli G. To sleep or not to sleep: a systematic review of the literature of pharmacological treatments of insomnia in children and adolescents with attention-deficit/hyperactivity disorder. J Child Adolesc Psychopharmacol. 2013;23:640. doi:10.1089/cap.2013.0059

We examined the effectiveness of various sleep medications, including L-theanine, for children and adolescents with ADHD. Out of 337 articles, only five were relevant.

While L-theanine showed some improvement in sleep efficiency, it did not significantly reduce sleep latency or increase overall sleep time. Other medications like clonidine and melatonin showed more promising results, reducing insomnia more effectively.

Overall, the lack of robust evidence for L-theanine suggests that more research is needed to confirm these findings and guide treatment options.

9.5

Great for insomnia relief

Most Useful Review

I started taking Theanine to help with my insomnia. Previously, I had difficulty finding an effective solution, and my doctor wasn't helpful. After starting Theanine, the nightly 3 AM awakenings ceased, and I no longer experience joint pain. I also noticed a reduction in my high blood pressure after taking it. After a week, my knees felt better than they have in a year, prompting me to increase my intake frequency.