NOW Supplements L-Theanine

3 people found this helpful

Adrenal Gland Disorder details

Enhanced sleep quality

Most Useful Review

An amazing tool! This is the first of the tried-and-true remedies from Ayherb, and I felt the results from the first day of taking it! I didn’t believe it myself, but my sleep was restored, and the insomnia vanished (though one must not stop and should look for the cause). My overall condition became softer, more comfortable, and I no longer felt drowsy during the day. This amino acid comes from tea, so it can be taken more frequently than L-thyroxine, as it needs to be secreted by the adrenal glands. I took one can, but after a couple of months, my nervousness and insomnia returned. Now I address this holistically by examining my adrenal glands and overall health. Overall, I really liked this product as it worked well for me!

1 people found this helpful

Food Poisoning details

NOW Foods Double Concentrated L-Theanine is an excellent supplement that exceeds expectations. The 200mg dose is just right, delivering a gentle, relaxing effect within about 30 minutes. Noteworthy is that it does not induce drowsiness, instead enhancing concentration. It's particularly effective at reducing stress, especially before deadlines. The veggie capsule is easy to swallow and nearly odourless. A pack of 120 capsules lasts about two months, offering good value. I take one capsule in the morning and another before work, yielding ideal results. Unlike caffeine, it can be taken late at night. As a reliable product from NOW Foods, I see it as a worthwhile investment for improving my daily life.

High Cholesterol details

IP6 improves cholesterol levels

Moderately Effective

Based on 10 Researches

Okazaki Y, Katayama T. Dietary inositol hexakisphosphate, but not myo-inositol, clearly improves hypercholesterolemia in rats fed casein-type amino acid mixtures and 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane. Nutr Res. 2008;28:714. doi:10.1016/j.nutres.2008.07.003

We examined the effects of inositol hexakisphosphate (IP6) and myo-inositol on high cholesterol in rats. In our study, we found that dietary IP6 effectively reduced increased cholesterol levels caused by a specific chemical exposure, while myo-inositol did not show significant benefits.

Additionally, IP6 also contributed to body weight gain, regardless of other dietary factors. Overall, while both inositol types helped prevent fatty liver, only IP6 demonstrated a clear advantage in managing hypercholesterolemia.

7.5

Calmness achieved

Most Useful Review

10 people found this helpful

It genuinely works. The quality is excellent, and after 2-3 weeks of use, I felt much calmer. I previously suffered from anxiety and panic attacks, but now, having taken it for three months, I feel significantly more relaxed. The benefits are immense, and I highly recommend it. The packaging is convenient, and the tablet size is easy to manage. I’ve noticed an increase in my overall energy throughout the day, and I'm glad to have it with me.

Updated: Mar 2026

Hypothyroidism details

Myo-inositol reduces thyroid nodule size

Moderately Effective

Based on 11 Researches

Nordio M, Basciani S. Evaluation of thyroid nodule characteristics in subclinical hypothyroid patients under a myo-inositol plus selenium treatment. Eur Rev Med Pharmacol Sci. 2018;22:2153. doi:10.26355/eurrev_201804_14749

We conducted an observational study to explore how myo-inositol (MI) combined with selenium (Se) impacts patients with subclinical hypothyroidism (SCH) and associated thyroid nodules (TNs).

Our research involved 642 patients suspected of having hypothyroidism, focusing on a subset with SCH. We divided them into two groups: one that received the MI plus Se treatment for six months and a control group that did not receive any treatment.

Among the received results, we found that the treatment group showed a significant reduction in the size and number of mixed TNs, alongside an improved elasticity score. Remarkably, TSH levels also dropped significantly after treatment, indicating a positive response. In contrast, the control group experienced an increase in TSH levels, highlighting the potential benefits of MI plus Se for managing symptoms of hypothyroidism.

These findings suggest promising avenues for further research, particularly regarding the role of inositol in thyroid health. While we observed substantial benefits in the treated group, we also emphasize the need for more extensive studies to confirm these effects and their mechanisms.

7.5

Energy boost

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3 people found this helpful

As someone with subclinical hypothyroidism, I often feel low in energy. Taking L-Theanine with coffee before workouts provides a fantastic energy boost. Even without coffee, it enhances cognitive function, making concentration and memory more manageable.

Updated: Mar 2026

Atrial Septal Defect details

1 people found this helpful

We love this! Recommended by my holistic doctor for my son with atrial septal defect. This has been incredibly helpful. Our experience shows that when combined with GABA and taurine, it surpasses traditional medications. I would definitely recommend this for those grappling with learning disabilities before considering anti-anxiety medication, which can have more serious side effects.

Blood Clot details

SCI offers safe anticoagulant potential

Likely Very Effective

Al-Horani RA, Abdelfadiel EI, Afosah DK, Morla S, Sistla JC, et al. A synthetic heparin mimetic that allosterically inhibits factor XIa and reduces thrombosis in vivo without enhanced risk of bleeding. J Thromb Haemost. 2019;17:2110. doi:10.1111/jth.14606

We explored the effects of a synthetic heparin mimetic known as sulfated chiro-inositol (SCI) on blood clotting mechanisms. This innovative treatment aims to inhibit human factor XIa (FXIa), a key player in the clotting process, while minimizing bleeding risks typically associated with anticoagulants.

In our study, we synthesized SCI to engage FXIa specifically by targeting its heparin-binding sites. Through various blood coagulation assays and in vivo models, we observed that SCI effectively inhibited FXIa, leading to reduced clot formation without significant safety concerns. In particular, SCI demonstrated potent anticoagulant properties, matching the performance of existing treatments like enoxaparin but at a much lower dosage.

Importantly, our investigations revealed that SCI's effects could be reversed by common antidotes, which adds an important layer of safety. While we noted no major bleeding risks or toxicity in the studies, further research is needed to ensure SCI's efficacy across broader clinical scenarios. Overall, our findings highlight SCI as a promising candidate for safer anticoagulation therapies.

7.5

Improved sleep quality

Most Useful Review

Everything aligns with the manufacturer's claims. I've become calmer, and although my blood pressure is high, taking the supplement at night helps improve my sleep quality.

Updated: Mar 2026

Menopause details

Myo-Inositol Support in Menopause

Based on 9 Researches

Cho KA, Kim YH, Woo SY, Ryu KH. Tonsil-Derived Mesenchymal Stem Cell-Derived Small Extracellular Vesicles (sEVs) Restore Myo-Inositol Production in LPS-Treated Skeletal Muscle. Tissue Eng Regen Med. 2025. doi:10.1007/s13770-025-00709-w

We investigated whether small extracellular vesicles (sEVs) derived from human palatine tonsil mesenchymal stem cells could boost myo-inositol levels in the context of menopause. This was particularly interesting given that menopausal women are prone to chronic inflammation due to physiological changes and related issues like metabolic syndrome.

To explore this, we treated mice with lipopolysaccharides (LPS) to simulate inflammation and assessed how the inclusion of T-MSC sEVs influenced myo-inositol production. After treatment, we measured levels of proteins involved in inositol synthesis in skeletal muscle and checked the serum for inositol levels.

Our findings are encouraging and suggest that T-MSC sEVs might help mitigate some effects of chronic inflammation linked to menopause. By supporting skeletal muscle mass and maintaining myo-inositol levels, these sEVs could be an effective strategy for improving metabolic health in menopausal women. This study sheds light on a potential new approach to tackle metabolic disturbances during this life stage.

Calmness achieved

Most Useful Review

1 people found this helpful

I’m in peri-menopause and experience mood swings and severe anxiety. L-theanine helps calm me without causing drowsiness. I take two a day, ensuring to take them on an empty stomach, either half an hour before breakfast or two hours after dinner.

Updated: Mar 2026

Weight Loss details

Questionable

Myo-inositol aids insulin sensitivity

Genazzani AD, Prati A, Santagni S, Ricchieri F, Chierchia E, et al. Differential insulin response to myo-inositol administration in obese polycystic ovary syndrome patients. Gynecol Endocrinol. 2012;28:969. doi:10.3109/09513590.2012.685205

We investigated how myo-inositol affects insulin sensitivity and weight in obese women with polycystic ovary syndrome (PCOS). After 8 weeks of treatment with 2 grams daily, we observed a decrease in body mass index, insulin resistance, and several hormonal levels. Interestingly, women with higher initial insulin levels experienced the most significant improvements, particularly in their fasting insulin levels. This suggests that myo-inositol may be especially beneficial for those struggling with elevated insulin in conjunction with PCOS.

7.5

Stress reduction

Most Useful Review

7 people found this helpful

I will buy this product again! My digestion and bowel function have improved since I started taking it and my weight has dropped. I take it on an empty stomach, one or two a day. L-theanine (γ-glutamyl ethylamide) is a unique non-protein amino acid found in green tea (Camellia sinensis). It lowers anxiety and cortisol levels, improving sleep quality before bedtime. I feel less stressed, and my weight has reduced since I began this, although I've also been taking butyrate and a preparation containing EGCG.

Updated: Mar 2026

Attention Deficit Hyperactivity Disorder details

105 people found this helpful

The WOW effect is felt 10-20 minutes after ingestion. I drink it with caffeine before tackling difficult tasks. Caffeine lifts my spirits while theanine sharpens my concentration. The feeling is extraordinary, as though I am in a high state of focus and nothing can distract me. It's a miracle!

Super remedy! It provides good sleep, excellent performance, and improved vision. I really like it and plan to take it regularly.

Blurred Vision details

Excellent performance

Most Useful Review

Diabetes details

Myo-inositol aids gestational diabetes

Based on 10 Researches

Chen H, Xiong J, Li Z, Chen Y, Zhang M, et al. Influence of myo-inositol on metabolic status for gestational diabetes: a meta-analysis of randomized controlled trials. J Matern Fetal Neonatal Med. 2024;37:2228450. doi:10.1080/14767058.2023.2228450

We aimed to evaluate how myo-inositol supplementation affects women with gestational diabetes through a meta-analysis of randomized controlled trials. Our search included multiple databases, leading to the analysis of four studies involving 317 participants. The results showed that myo-inositol significantly reduced the need for insulin and improved insulin sensitivity. However, it did not influence birth weight, cesarean delivery rates, or NICU admissions. These findings suggest myo-inositol could be a helpful addition to managing gestational diabetes, but further research is needed.

7.5

Supports emotional stability

Most Useful Review

Works well! I gave it to my mother for emotional peace, and she found it beneficial. Her nerves have strengthened, and it has positively impacted her diabetes.

Updated: Mar 2026

Adhd details

L-theanine improves sleep in ADHD

Lyon MR, Kapoor MP, Juneja LR. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Altern Med Rev. 2011;16:348.

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.

Calming Effect

Most Useful Review

28 people found this helpful

What a Godsend! I saw on the television that Theanine was being tested with children who have ADHD. I recommend TwinLab and just 100 mg for kids. I have ADD, as does my daughter, and I love this stuff for me—far better than any antidepressant or anxiety medication I have taken! We are calmer now and don’t feel anxious anymore. I believe everyone should use Theanine. I prefer this brand above others, as it even gives me some extra energy. The best part is—there are no side effects that I have noticed! My mother and mother-in-law enjoy it as well!

Updated: Apr 2025

Common Cold details

A fantastic product, essential if you suffer from recurring sore colds.

Depression details

L-theanine shows potential antidepressant effects

Based on 8 Researches

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.

Fostered calmness

Most Useful Review

14 people found this helpful

During a challenging period of betrayal, this supplement provided much-needed support. After taking it, I felt noticeable calmness, bordering on euphoria, without the side effects of sleepiness. I felt like I was in a meditative state.

Updated: Mar 2026

Tinnitus details

There’s no sensation after one pill, but taking a deep breath brings relaxation. Occasionally, my tinnitus quietens. I’m interested in trying two pills at once; would that be possible?

Insomnia details

Likely Ineffective

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.

Life-changing results

Most Useful Review

25 people found this helpful

It changed my life! I'd been grappling with unwarranted stress, and despite trying various methods like meditation and appropriate medication, nothing worked. I discovered L-Theanine in an ADHD forum, where some noted its helpfulness with sleep and stress. After nearly a month of taking it alongside my morning tea, the stress faded. Most importantly, my insomnia improved; I now sleep for 6.5 hours straight, a true miracle for me! I find 100 mg might suit most, as 200 mg has a significant effect on me. I'll compare the two and update later.

Updated: Mar 2026

Back Pain details

3 people found this helpful

Microdosing L-theanine has been beneficial for my back pain caused by stress. Initially, I took it before bed, which didn’t help my sleep. I later found that taking one capsule in the morning and another in the evening, with green tea, promotes relaxation without causing drowsiness. The effect is reminiscent of MDMA microdosing; I feel a pleasant lightness and muscle relaxation. However, I advise against using it with alcohol as it can enhance intoxication.

Heart Attack details

ITPP enhances heart attack recovery

Likely Very Effective

Oknińska M, El-Hafny-Rahbi B, Paterek A, Mackiewicz U, Crola-Da Silva C, et al. Treatment of hypoxia-dependent cardiovascular diseases by myo-inositol trispyrophosphate (ITPP)-enhancement of oxygen delivery by red blood cells. J Cell Mol Med. 2020;24:2272. doi:10.1111/jcmm.14909

We explored the potential of myo-inositol trispyrophosphate (ITPP) as a treatment for heart attacks and its effect on heart tissue injured by low oxygen levels. This research indicates ITPP modifies hemoglobin in red blood cells, enhancing the delivery of oxygen throughout the body.

Using an animal model for myocardial infarction, we observed that ITPP administration provided significant protection against heart failure and aided in recovery from left ventricular remodeling following the heart attack.

In our laboratory studies, heart muscle cells exposed to low oxygen levels reacted quickly to ITPP treatment, showing increased activity of a protein known as HIF-1. Interestingly, this overactivity was countered by ITPP when it was in the red blood cells, which suggests a strong connection between shear stress from blood flow and oxygen release facilitated by the modified hemoglobin.

Overall, the findings indicate that ITPP could be a game-changer in treating injuries to heart tissues related to low oxygen or ischemia. This approach may open new avenues for effectively managing damage caused by heart attacks.

Panic attacks

Most Useful Review

I didn't like it; I had panic attacks with coffee. Before that, I took Nutricost, which was good.

Updated: Mar 2026

Dizziness details

Improved sleep quality

Most Useful Review

I’ve just tried this and find it's far better than melatonin. I take two tablets before bed, leading to more comfortable sleep without dizziness upon waking. I’ve ordered another bottle; it’s very good.

Autoimmune Disorder details

Potential benefits for autoimmune function

Questionable

Based on 6 Researches

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.

Improved mood evident

Most Useful Review

4 people found this helpful

I have ordered theanine for my brother based on a doctor's advice. After a month, his condition has significantly improved; he seems happier and more aware. I highly recommend theanine as an effective treatment for those dealing with stress and cognitive issues.

Updated: Apr 2025

Heart Disease details

L-theanine shows heart protection

Moderately Effective

Based on 6 Researches

García-Niño WR, Correa F, Zúñiga-Muñoz AM, José-Rodríguez A, Castañeda-Gómez P, et al. L-theanine abates oxidative stress and mitochondrial dysfunction in myocardial ischemia-reperfusion injury by positively regulating the antioxidant response. Toxicol Appl Pharmacol. 2024;486:116940. doi:10.1016/j.taap.2024.116940

We examined the effects of L-theanine, a natural amino acid, on heart health during a condition known as ischemia-reperfusion (I/R) injury. In our study with rats, we found that L-theanine significantly improved heart function after I/R stress. It reduced oxidative damage and preserved mitochondrial health, indicating that it promotes antioxidant defenses in cardiac tissue. By enhancing the activity of important antioxidant enzymes and adjusting gene expression, L-theanine appears to provide vital protection against heart injury. However, further research is required to solidify L-theanine's role in heart disease treatment.

Anxiety alleviation

Most Useful Review

1 people found this helpful

L-theanine has greatly helped with my anxiety. Previously, my heart would race uncontrollably in stressful situations, but now I feel much calmer and can approach my day without that constant stress.

Updated: Mar 2026

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.

Pain relief

Most Useful Review

17 people found this helpful

I used to wake up with jaw aches, and my dentist informed me that I was clenching my teeth in my sleep, affecting my teeth. Since I began taking 400 mg of L-Theanine before bed, I no longer experience any pain!

Updated: Mar 2026

Irritable Bowel Syndrome details