What is the effectiveness of melatonin (melatonin) versus magnesium glycinate (magnesium glycinate) versus usual sleep hygiene in improving sleep quality among adult patients?

Sleep Quality Improvement in Adult Patients: Melatonin vs Magnesium Glycinate vs Sleep Hygiene

Sleep hygiene alone should not be used as a single-component therapy for improving sleep quality in adults with chronic insomnia, as it has minimal effectiveness compared to other interventions and may delay access to more effective treatments. 1

Evidence Against Sleep Hygiene as Monotherapy

The American Academy of Sleep Medicine makes a conditional recommendation against using sleep hygiene as single-component therapy for chronic insomnia disorder in adults 1. The evidence base reveals:

• Only 2 of 3 RCTs showed clinically meaningful improvements in any critical outcome with sleep hygiene alone, and the overall quality of evidence was low due to imprecision and risk of bias 1
• In the one study demonstrating benefit, patients spontaneously made additional behavioral changes (like standardizing sleep schedules) beyond what was instructed, and even in that study, CBT-I was superior to sleep hygiene alone 1
• When compared head-to-head with active treatments, sleep hygiene was consistently less effective than sleep restriction therapy, stimulus control, or combined behavioral interventions 1
• Sleep hygiene showed no clinically significant improvements in sleep efficiency, total wake time, or total sleep time when measured objectively 1

Clinical Pitfall: Allocating resources to sleep hygiene alone may divert patients away from more effective behavioral interventions and delay appropriate treatment 1.

Evidence for Melatonin

The evidence for melatonin is insufficient to make a firm recommendation, though it remains commonly prescribed:

• Critical care guidelines make no recommendation regarding melatonin use due to very low quality evidence 1
• Three small RCTs (n=60 total) in ICU patients with chronic respiratory failure showed nonsignificant improvements in sleep quality and quantity 1
• Melatonin has minimal adverse effects (sedation, headache) and is inexpensive, but manufacturing in the US is not FDA-regulated, raising concerns about product quality and consistency 1
• One study combining melatonin (5 mg) with magnesium (225 mg) and zinc (11.25 mg) in long-term care residents showed significant improvements in Pittsburgh Sleep Quality Index scores (difference between groups = 6.8, p<0.001) and total sleep time (p<0.001) 2

Important Caveat: The positive study 2 used a combination supplement, making it impossible to isolate melatonin's independent effect from magnesium or zinc.

Evidence for Magnesium Glycinate

No direct evidence exists for magnesium glycinate as monotherapy for sleep improvement. The only relevant study used magnesium in combination with melatonin and zinc 2. This study showed:

• Significant improvements in all four domains of the Leeds Sleep Evaluation Questionnaire (ease of getting to sleep p<0.001, quality of sleep p<0.001, hangover on awakening p=0.005, alertness the following morning p=0.001) 2
• Improved quality of life scores (SF-36 physical score p=0.006) 2

However, this evidence cannot be extrapolated to magnesium glycinate alone, as the intervention was multicomponent.

Alternative Evidence-Based Approaches

If behavioral interventions are being considered, the evidence strongly supports:

• Sleep restriction therapy delivered by nurses in primary care showed large treatment effects (Cohen's d = -0.74 at 6 months) with mean Insomnia Severity Index improvement of -3.05 points (95% CI -3.83 to -2.28, p<0.001) compared to sleep hygiene 3, 4
• This intervention was cost-effective at £2,076 per QALY gained with 95.3% probability of cost-effectiveness at the £20,000 threshold 3, 4
• Effects were sustained at 12 months (Cohen's d = -0.72) 4

For hospitalized patients specifically:

• Noise and light reduction strategies are suggested to improve sleep quality 5
• Earplugs and eyeshades improve patient-reported sleep quality and reduce delirium 5
• A multicomponent sleep hygiene bundle (including eye mask, earplugs, lavender, relaxing music, and environmental modifications) showed modest improvements in Richards-Campbell Sleep Questionnaire scores (6.0 to 6.2, p=0.041) 6

Clinical Algorithm

For adults with chronic insomnia:

1. Do not use sleep hygiene alone as it has minimal effectiveness 1
2. Consider sleep restriction therapy as first-line behavioral treatment (strongest evidence for effectiveness) 3, 4
3. Melatonin may be tried given minimal adverse effects and low cost, but set realistic expectations given weak evidence 1
4. Avoid magnesium glycinate as monotherapy due to absence of evidence for this specific formulation
5. If using supplements, consider the combination of melatonin 5 mg + magnesium 225 mg + zinc 11.25 mg based on the one positive trial 2, though this is extrapolating from a long-term care population

For hospitalized patients:

1. Implement environmental modifications (noise/light reduction, earplugs, eyeshades) as these have the best evidence in this setting 5, 6
2. Cluster care activities to minimize nighttime interruptions 5
3. Melatonin has no recommendation in critically ill adults due to very low quality evidence 1

Critical Point: Sleep hygiene may be included as part of multicomponent interventions but should never be the sole treatment approach 1.