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L-Theanine 用于 Attention & Focus Difficulties

B

The L-theanine + caffeine combination is one of the most replicated nootropic pairings in cognitive research, consistently showing improvements in attention, task switching, and alertness without jitteriness.

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结论

            
            
The L-theanine + caffeine combination is one of the most replicated nootropic pairings in cognitive research, consistently showing improvements in attention, task switching, and alertness without jitteriness.

            
            
        

    










    

  
Key Study Findings





    

        
        

            

                
                    Systematic Review
                
                
                
                
            

            
                Efficiency of Different Supplements in Alleviating Symptoms of ADHD with or Without the Use of …
            
            

                
                Dose: None
                
                
                vs: Placebo or methylphenidate
                
                
                Outcome: ADHD symptom severity (inattention, hyperactivity)
                
                
                效果: None
                
                
                None
                
            

            
            
研究人群: ADHD patients (systematic review of supplements)

            
        

        
        

            

                
                    Systematic Review
                
                
                
                
            

            
                The effects of L-theanine supplementation on the outcomes of patients with mental disorders: a systematic …
            
            

                
                Dose: None
                
                
                vs: None
                
                
                Outcome: Anxiety symptoms
                
                
                效果: None
                
                
                None
                
            

            
            
研究人群: Schizophrenia patients

            
        

        
        

            

                
                    Systematic Review
                
                
                
                
            

            
                Association between sleep pattern and pharmacological treatment in children with attention deficit disorder with hyperactivity: …
            
            

                
                Dose: None
                
                
                vs: None
                
                
                Outcome: sleep quality
                
                
                效果: None
                
                
                None
                
            

            
            
研究人群: Children

            
        

        
        

            

                
                    Randomized Controlled Trial
                
                
                
                4.3 weeks
                
                
                Single-blind
                
            

            
                Assessing brain function in stressed healthy individuals following the use of a combination of green …
            
            

                
                Dose: None
                
                
                vs: placebo
                
                
                Outcome: Brain response to stress and quality of life
                
                
                效果: None
                
                
                p = 0.001
                
            

            
            
研究人群: Chronically stressed but healthy subjects

            
        

        
        

            

                
                    Systematic Review
                
                
                
                884 weeks
                
                
            

            
                The Cognitive-Enhancing Outcomes of Caffeine and L-theanine: A Systematic Review.
            
            

                
                Dose: 9.4%
                
                
                vs: None
                
                
                Outcome: None
                
                
                效果: None
                
                
                None
                
            

            
            
研究人群: None

            
        

        
        

            

                
                    Randomized Controlled Trial
                
                
                
                
            

            
                Effects of L-theanine-caffeine combination on sustained attention and inhibitory control among children with ADHD: a …
            
            

                
                Dose: 2.5 mg/kg
                
                
                vs: Placebo
                
                
                Outcome: None
                
                
                效果: None
                
                
                p = 0.040
                
            

            
            
研究人群: Children with ADHD

            
        

        
    







    
    

        
        

            

  
Key Statistics





            


    

        
20

        
研究数量

    

    

        
1500

        
受试者

    

    

        
            
            ↑
            
        
        
Positive

    

    

        B

        
等级

    




        


        
        
        

            

  
Referenced Papers





            

                
                

                    

                        
                            Efficiency of Different Supplements in Alleviating Symptoms of ADHD with or Without the Use of Stimulants: A Systematic Review.
                        
                        
                            
                                Systematic Review
                            
                            
                            
                        
                    

                    

                        Nutrients
                        2025
                        
                        1 次引用
                        
                    

                

                
                

                    

                        
                            The effects of L-theanine supplementation on the outcomes of patients with mental disorders: a systematic review.
                        
                        
                            
                                Systematic Review
                            
                            
                            
                        
                    

                    

                        BMC psychiatry
                        2024
                        
                        12 次引用
                        
                    

                

                
                

                    

                        
                            Association between sleep pattern and pharmacological treatment in children with attention deficit disorder with hyperactivity: a systematic review.
                        
                        
                            
                                Systematic Review
                            
                            
                            
                        
                    

                    

                        Revista paulista de …
                        2023
                        
                        3 次引用
                        
                    

                

                
                

                    

                        
                            Assessing brain function in stressed healthy individuals following the use of a combination of green tea, Rhodiola, magnesium, and B …
                        
                        
                            
                                Other
                            
                            
                            
                        
                    

                    

                        Frontiers in nutrition
                        2023
                        
                        3 次引用
                        
                    

                

                
                

                    

                        
                            The Cognitive-Enhancing Outcomes of Caffeine and L-theanine: A Systematic Review.
                        
                        
                            
                                Review
                            
                            
                            
                        
                    

                    

                        Cureus
                        2021
                        
                        20 次引用
                        
                    

                

                
                

                    

                        
                            Effects of L-theanine-caffeine combination on sustained attention and inhibitory control among children with ADHD: a proof-of-concept neuroimaging RCT.
                        
                        
                            
                                RCT
                            
                            
                            
                        
                    

                    

                        Scientific reports
                        2020
                        
                        34 次引用
                        
                    

                

                
                

                    

                        
                            L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial.
                        
                        
                            
                                RCT
                            
                            
                            
                        
                    

                    

                        Journal of psychiatric …
                        2019
                        
                        46 次引用
                        
                    

                

                
                

                    

                        
                            Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study.
                        
                        
                            
                                Other
                            
                            
                            
                        
                    

                    

                        Acta neuropsychiatrica
                        2017
                        
                        84 次引用
                        
                    

                

                
                

                    

                        
                            The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, …
                        
                        
                            
                                RCT
                            
                            
                            
                        
                    

                    

                        Alternative medicine review …
                        2011
                        
                        82 次引用
                        
                    

                

                
            

        

        

        
        
        

            

  
Dosage & Usage





            
mg = milligrams · mcg = micrograms (1,000× smaller) · IU = International Units


            
            

                
常用剂量

                

                    
                    

                        
general:

                        
100-200 mg/day

                    

                    
                    

                        
withcaffeine:

                        
200 mg L-theanine + 100 mg caffeine

                    

                    
                

                
                

                    上限： 900 mg/day (no adverse effects observed in studies)
                

                
            

            

            
            

                
研究中使用的剂量

                

                    

                        
                            

                                剂量
                                持续时间
                                效果
                                N
                            

                        
                        
                            
                            

                                None
                                --
                                
                                    
                                    Mixed
                                    
                                
                                --
                            

                            
                            

                                None
                                --
                                
                                    
                                    Positive
                                    
                                
                                --
                            

                            
                            

                                None
                                --
                                
                                    
                                    Mixed
                                    
                                
                                --
                            

                            
                            

                                None
                                4.3 weeks
                                
                                    
                                    Positive
                                    
                                
                                --
                            

                            
                            

                                9.4%
                                884 weeks
                                
                                    
                                    Positive
                                    
                                
                                --
                            

                            
                            

                                2.5 mg/kg
                                --
                                
                                    
                                    Negative
                                    
                                
                                --
                            

                            
                            

                                450-900 mg L-theanine daily
                                10 weeks
                                
                                    
                                    Neutral
                                    
                                
                                46
                            

                            
                            

                                250 mg/day
                                8 weeks
                                
                                    
                                    Positive
                                    
                                
                                20
                            

                            
                        
                    

                

            

            

            
            

                最佳服用时间： Morning or as needed; rapid onset (30-60 minutes)
            

            
        

        

        
        
        

            

  
Safety & Side Effects





            

                
                

                    
已报告的副作用

                    
    
                        
                        
  • 
                            ⚠
                            Generally very well-tolerated
                        
    • 
                        
                        
  • 
                            ⚠
                            Mild drowsiness in sensitive individuals
                        
    • 
                        
                        
  • 
                            ⚠
                            Mild headache (rare)
                        
    • 
                        
                    

                

                

                
                

                    
已知相互作用

                    
    
                        
                        
  • 
                            ●
                            Antihypertensive drugs (may enhance blood pressure lowering)
                        
    • 
                        
                        
  • 
                            ●
                            Stimulant medications (counteracts some stimulant side effects)
                        
    • 
                        
                        
  • 
                            ●
                            Sedative medications (additive calming effects)
                        
    • 
                        
                    

                

                

                
                

                    

                        可耐受最高摄入量： 900 mg/day (no adverse effects observed in studies)
                    

                

                
            

            

                在开始服用任何补充剂之前，请务必咨询您的医疗保健提供者。
            

        

        

        
        
        

            

  
Frequently Asked Questions





            




    
    

        
            Does L-Theanine help with Attention & Focus Difficulties?
            
        
        

            Based on 20 studies with 1,500 participants, there is moderate evidence from clinical studies that L-Theanine may support Attention & Focus Difficulties management. Our evidence grade is B (Good Evidence).
        

    

    
    

        
            How much L-Theanine should I take for Attention & Focus Difficulties?
            
        
        

            Studies have used various dosages. A commonly studied range is 100-200 mg/day. Always consult your healthcare provider before starting any supplement regimen.
        

    

    
    

        
            Are there side effects of L-Theanine?
            
        
        

            Reported side effects may include Generally very well-tolerated, Mild drowsiness in sensitive individuals, Mild headache (rare). Most side effects are mild and dose-dependent. Consult your doctor if you experience any adverse reactions.
        

    

    
    

        
            How strong is the evidence for L-Theanine and Attention & Focus Difficulties?
            
        
        

            We rate the evidence as Grade B (Good Evidence). This rating is based on 20 peer-reviewed studies with 1,500 total participants. The overall direction of effect is positive.
        

    

    




        

        

        
        
        

            

  
Related Evidence





            

                
                
                

                
                
                
            

        

        

    


    
    












    

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