Is it recommended to take 5mg of melatonin supplement with 100mg of L-theanine (l-theanine)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 5, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Taking 5mg of melatonin with 100mg of L-theanine is generally considered safe for most healthy adults, though you should consult with a healthcare provider before combining supplements. Both supplements are commonly used for sleep support and can work complementarily - melatonin helps regulate sleep-wake cycles while L-theanine promotes relaxation without sedation. The 5mg melatonin dose is on the higher end of typical recommendations, as the American Academy of Sleep Medicine suggests that the optimal dosing of melatonin for circadian effects remains unclear, and studies suggest that timing is more important than dose 1. However, a more recent study from 2023 recommends a starting dose of immediate-release melatonin of 3 mg taken at bedtime, which may be titrated up to address dream enactment in 3-mg increments to 15 mg 1. L-theanine at 100mg is within the standard dosage range (100-200mg). Take this combination about 30-60 minutes before bedtime for optimal effect. Some people experience morning grogginess with higher melatonin doses, so monitor how you feel upon waking. These supplements may interact with certain medications including blood thinners, immunosuppressants, and sedatives, so disclosure to your doctor is important if you take prescription medications, as noted in a 2021 study that recommends continuing melatonin in the perioperative period due to its safety profile 1.

Key considerations for taking melatonin and L-theanine include:

  • Starting with a lower dose of melatonin to assess effectiveness
  • Monitoring for potential interactions with other medications
  • Being aware of the potential for morning grogginess with higher melatonin doses
  • Consulting with a healthcare provider before combining supplements, especially if you have any underlying medical conditions or take prescription medications.

It's also important to note that while melatonin and L-theanine can be beneficial for sleep support, they may not be suitable for everyone, and individual results may vary. Always prioritize consulting with a healthcare provider before adding any new supplements to your regimen.

From the Research

Melatonin and L-Theanine Supplementation

  • There is no direct evidence in the provided studies to support or recommend taking 5mg of melatonin supplement with 100mg of L-theanine for insomnia or sleep disorders 2, 3, 4, 5, 6.
  • The studies focus on the effectiveness of cognitive behavioral therapy for insomnia (CBT-i) as a non-pharmacological treatment for chronic insomnia, highlighting its benefits and recommending it as a first-line treatment 2, 3, 4, 5, 6.
  • None of the studies mention the use of melatonin or L-theanine supplements in combination or alone for the treatment of insomnia.
  • It is essential to consult with a healthcare professional before taking any supplements, especially when considering combining them, as they may interact with other medications or have adverse effects.

Cognitive Behavioral Therapy for Insomnia (CBT-i)

  • CBT-i is a multi-component treatment that targets difficulties with initiating and/or maintaining sleep, delivered over six to eight sessions 4.
  • The primary focus of CBT-i is to address the perpetuating factors that contribute to the development of chronic insomnia, with core components including sleep restriction therapy, stimulus control therapy, sleep hygiene, and cognitive therapy 4.
  • Studies have shown that CBT-i is an effective treatment for adults with chronic insomnia, with clinically meaningful effect sizes and sustained benefits over time 3, 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Cognitive Behavioral Therapy for Insomnia (CBT-I): A Primer.

Klinicheskaia i spetsial'naia psikhologiia = Clinical psychology and special education, 2022

Research

Efficacy of cognitive behavioral therapy for insomnia (CBT-I) in older adults with insomnia: A systematic review and meta-analysis.

Australasian psychiatry : bulletin of Royal Australian and New Zealand College of Psychiatrists, 2022

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.