What is the recommended dosage of glycine (amino acid) for improving sleep quality and reducing inflammation?

Glycine for Improving Sleep Quality and Reducing Inflammation

For improving sleep quality, glycine can be taken at a dose of 3 grams before bedtime, which has been shown to improve subjective sleep quality and reduce daytime fatigue in individuals with sleep disturbances. This dosage has demonstrated efficacy in reducing fatigue and improving daytime performance in sleep-restricted individuals 1.

Mechanism of Action

Glycine works through several mechanisms to improve sleep:

• Decreases core body temperature by increasing peripheral blood flow, which is associated with sleep onset 2
• Activates NMDA receptors in the suprachiasmatic nucleus (SCN) shell, promoting sleep through peripheral vasodilation 2
• Inhibits orexin neurons, which are responsible for wakefulness, leading to increased NREM sleep time 3
• Transiently increases serotonin levels in the prefrontal cortex, which may contribute to improved sleep quality 4

Dosage Recommendations

• Standard dose: 3 grams taken orally before bedtime 1
• This dosage has been studied in clinical trials and shown to:
  • Reduce subjective fatigue
  • Improve daytime performance
  • Enhance sleep quality
  • Decrease time to fall asleep

Evidence for Anti-inflammatory Effects

While glycine is primarily studied for its sleep-promoting properties, it may also have anti-inflammatory effects through:

• Modulation of immune function
• Potential reduction in pro-inflammatory cytokines

However, the evidence specifically for anti-inflammatory effects is less robust than for sleep improvement.

Clinical Application

For patients with insomnia or sleep disturbances:

1. Start with non-pharmacological approaches like Cognitive Behavioral Therapy for Insomnia (CBT-I) as first-line treatment 5
2. If additional support is needed, glycine can be considered as a dietary supplement at 3 grams before bedtime
3. Monitor subjective sleep quality and daytime fatigue

Safety Considerations

• Glycine is generally well-tolerated as a dietary supplement
• Unlike benzodiazepines and other sleep medications, glycine does not appear to cause:
  • Dependency or tolerance
  • Cognitive impairment
  • Daytime sedation
  • Risk of falls

Alternative Options for Sleep

If glycine is ineffective, other evidence-based options include:

• Melatonin (3-12 mg) for sleep onset issues 6
• Low-dose doxepin (3-6 mg) for sleep maintenance 5
• Suvorexant (10-20 mg) for sleep maintenance insomnia 5

Practical Tips

• Take glycine approximately 30-60 minutes before bedtime
• Consistency is important for optimal results
• Can be combined with good sleep hygiene practices for enhanced effects
• May be particularly beneficial for those with sleep restriction or insomnia tendencies

Glycine represents a relatively safe, non-prescription option for improving sleep quality with minimal side effects compared to traditional sleep medications.