What is a safe and effective dose of L-theanine (amino acid) for an 11-year-old female?

L-Theanine Dosing for an 11-Year-Old Female

Based on available evidence, a dose of 200 mg daily of L-theanine appears to be safe and appropriate for an 11-year-old female, though no FDA-approved pediatric dosing guidelines exist for this supplement.

Evidence-Based Dosing Recommendations

Adult Dosing as Reference Point

• Standard adult doses range from 200-400 mg daily for anxiety, stress, and sleep support, administered safely for up to 8 weeks in clinical trials 1
• The most commonly studied and effective dose is 200 mg daily, which has demonstrated anxiolytic effects and improved sleep quality without sedation 2
• Higher doses of 400 mg daily have been used safely in adults with moderate stress for 28 days and in psychiatric patients for 8 weeks 3, 4

Pediatric Considerations

• No specific pediatric dosing guidelines exist in medical literature or FDA labeling for L-theanine, as it is classified as a dietary supplement rather than a pharmaceutical agent
• The safety profile in children has not been systematically studied in controlled trials
• Weight-based extrapolation from adult dosing would be the most conservative approach: an 11-year-old female typically weighs 30-45 kg (average ~36 kg), which is approximately 50-60% of average adult weight (70 kg)

Recommended Starting Approach

• Begin with 100-200 mg daily, preferably starting at the lower end (100 mg) and titrating up based on response and tolerability 1
• Administer as a single daily dose, typically in the evening if used for sleep support, or divided into twice-daily dosing if used for daytime anxiety 2
• The supplement can be taken at any time of day as it does not cause daytime drowsiness 2

Safety Profile

Established Safety Data

• The no observable adverse effect level (NOAEL) is above 2000 mg/kg body weight per day in toxicology studies, indicating a very wide safety margin 2
• For a 36 kg child, this translates to a theoretical maximum safe dose exceeding 72,000 mg daily—far above any therapeutic dose
• Doses of 200-400 mg daily have been safe and well-tolerated in adult studies lasting up to 8 weeks with no significant adverse events 1, 3, 4

Important Caveats

• L-theanine is not a sedative but works through anxiolysis and does not cause dependence or withdrawal 2
• Rare cases of hepatotoxicity have been reported with green tea extract (not isolated L-theanine), so monitoring for any signs of liver dysfunction is prudent if using for extended periods 1
• No drug interactions of clinical significance have been reported in the literature reviewed

Clinical Monitoring

What to Assess

• Baseline assessment should include the specific indication (anxiety, sleep disturbance, stress, attention issues) and severity
• Response evaluation at 2 weeks and 4 weeks, looking for improvements in target symptoms
• Tolerability check for any gastrointestinal symptoms, headache, or behavioral changes (though these are rare)
• Consider discontinuation if no benefit is observed after 4-6 weeks of adequate dosing

Duration of Use

• Studies support safe use for 8 weeks at therapeutic doses 1, 3
• Longer-term safety data in children is lacking, so periodic reassessment of need for continued supplementation is warranted
• Unlike pharmaceutical sleep aids or anxiolytics, L-theanine does not require tapering for discontinuation 2

Practical Implementation

Start with 100 mg once daily (or 200 mg if the child weighs >40 kg and symptoms are moderate to severe), taken either in the morning for daytime anxiety/attention support or in the evening 30-60 minutes before bed for sleep support 2, 1. If well-tolerated but insufficient response after 2 weeks, increase to 200 mg daily (or 400 mg if already at 200 mg and child weighs >40 kg) 3. This conservative approach balances the lack of pediatric-specific data with the excellent safety profile demonstrated in adults.