Over-the-Counter Sleep Aids: Evidence-Based Recommendations
Direct Answer
Most over-the-counter sleep aids lack robust evidence for efficacy and safety, and long-term use is not recommended. The American Academy of Sleep Medicine explicitly advises against using melatonin, valerian, antihistamines, and other herbal supplements for chronic insomnia due to insufficient evidence and potential harms. 1, 2
Melatonin
Efficacy Evidence
- Melatonin produces only small effects on sleep latency (approximately 9 minutes reduction) with minimal impact on wake after sleep onset or total sleep time. 1, 2
- Meta-analyses demonstrate that melatonin has been tested primarily as a chronobiotic (phase-shifting agent) rather than as a hypnotic, which explains its limited efficacy for insomnia treatment. 1
- Prolonged-release melatonin formulations in older adults (≥55 years) show the most consistent beneficial effects on sleep onset and quality, with favorable tolerability. 3
Dosing by Age Group
Safety Profile
- Side effects are mild at usual doses, with no evidence of toxicity, severe adverse effects, or dependence even at high doses. 4
- The American Academy of Sleep Medicine recommends against using melatonin for sleep onset or maintenance insomnia in adults despite its widespread availability. 2
Magnesium
Efficacy Evidence
- In elderly patients with primary insomnia, magnesium supplementation (500 mg daily for 8 weeks) significantly improved sleep time, sleep efficiency, sleep onset latency, and early morning awakening compared to placebo. 5
- Magnesium increased serum renin and melatonin concentrations while decreasing cortisol levels, suggesting a physiologic mechanism through NMDA antagonism and GABA agonism. 5
- The Insomnia Severity Index score decreased significantly with magnesium supplementation. 5
Dosing
- 500 mg daily is the evidence-based dose for elderly adults with insomnia. 5
Limitations
- Evidence is limited to elderly populations; data in younger adults are insufficient. 6
- Clinical trial results for magnesium remain conflicting across studies. 6
First-Generation Antihistamines (Diphenhydramine, Doxylamine)
Efficacy Evidence
- The American Academy of Sleep Medicine explicitly recommends against antihistamines for insomnia due to very limited efficacy data, lack of contemporary study designs, and potential for serious anticholinergic side effects. 1, 2
- Diphenhydramine showed statistically significant sedation and decreased awakenings in some studies but lacks robust evidence of safety or superiority over other agents. 7
- Tolerance develops after only 3–4 days of use, rendering antihistamines ineffective for ongoing insomnia. 8
Safety Concerns
- Anticholinergic properties cause daytime sedation, delirium (especially in elderly and advanced illness), confusion, urinary retention, and falls. 1, 8
- The National Cancer Institute warns about cautious use in older patients and those with advanced cancer due to increased delirium risk. 1
Guideline Position
- Over-the-counter antihistamines are not recommended for treating sleep onset or maintenance insomnia. 8, 2
Valerian
Efficacy Evidence
- Valerian has small but consistent effects on sleep latency, with inconsistent effects on sleep continuity, duration, and sleep architecture. 1
- A systematic review of 14 randomized trials found no differences between valerian and placebo on critical insomnia outcomes including daytime functioning, insomnia severity, sleep efficiency, sleep latency, total sleep time, or sleep quality. 9
- A phase III trial in cancer patients showed no effect of valerian (450 mg) on sleep quality measured by the Pittsburgh Sleep Quality Index. 1, 9
Guideline Position
- The American Academy of Sleep Medicine recommends against using valerian for sleep onset or maintenance insomnia in adults. 2, 9
- Studies lack robust clinical evidence supporting efficacy and safety. 3
L-Theanine
Evidence
- L-theanine has minimal research support for sleep improvement; additional studies are needed before it can be appropriately recommended. 6
- No guideline-level recommendations exist for L-theanine in insomnia treatment.
5-HTP (L-Tryptophan)
Efficacy Evidence
- The American Academy of Sleep Medicine recommends against tryptophan for sleep onset or maintenance insomnia in adults. 2
- Evidence shows modest decline in total sleep time, slight decrease in wake after sleep onset, and mild increase in sleep quality, but none met thresholds for clinical significance. 2
Cannabidiol (CBD)
Evidence
- No guideline-level evidence was identified for CBD in the treatment of primary insomnia.
- Insufficient data exist to make evidence-based recommendations.
Recommended First-Line Approach
Cognitive Behavioral Therapy for Insomnia (CBT-I)
- CBT-I should be the initial treatment for chronic insomnia before considering any medication, as it demonstrates superior long-term efficacy with sustained benefits after discontinuation. 8, 2
- Components include stimulus control therapy, sleep restriction therapy, relaxation techniques, cognitive restructuring, and sleep hygiene education. 8
Sleep Hygiene Foundations
- Maintain a regular sleep-wake schedule 2
- Avoid daytime napping 2
- Limit caffeine (avoid for at least 6 hours before bedtime) and alcohol 2
- Create a comfortable sleep environment 2
When Pharmacotherapy Becomes Necessary
First-Line Prescription Options
- Low-dose doxepin (3–6 mg) is most appropriate for sleep maintenance insomnia with a favorable efficacy and safety profile. 8, 2
- Ramelteon (8 mg) may be considered for sleep onset insomnia. 8, 2
- Short-acting benzodiazepine receptor agonists (eszopiclone, zolpidem, zaleplon) are first-line when pharmacotherapy is necessary after CBT-I initiation. 8
Medications to Avoid
- Trazodone is not recommended for sleep onset or maintenance insomnia. 8, 2
- Alcohol should be avoided despite being a common self-treatment due to short duration of action, adverse effects on sleep, exacerbation of obstructive sleep apnea, and potential for abuse. 1, 2
Critical Safety Warnings
Long-Term Use
- Long-term use of non-prescription (over-the-counter) treatments is not recommended; efficacy and safety data are limited to short-term studies, and their safety in long-term treatment is unknown. 1, 2
- Periodic attempts to reduce frequency and dose are indicated to minimize side effects and determine the lowest effective dose. 1
Rebound Insomnia
- On discontinuation after more than a few days' use, rebound insomnia (worsening of symptoms lasting 1–3 days), withdrawal effects, and recurrence may occur. 1
- Rebound can be minimized by gradually tapering both dose and frequency of administration. 1
Special Populations
- Elderly patients require lower doses (e.g., zolpidem maximum 5 mg) due to increased sensitivity and fall risk. 8
- Antihistamines pose particularly high risk in older adults and patients with advanced illness. 1
Common Pitfalls to Avoid
- Relying on over-the-counter sleep aids without first implementing CBT-I leads to less durable benefit and potential dependence. 8, 2
- Using antihistamines beyond 3–4 days results in tolerance and continued anticholinergic side effects without benefit. 8
- Assuming "natural" supplements like valerian and melatonin are effective based on availability rather than evidence. 1, 2, 9
- Failing to educate patients about risks of over-the-counter agents, including abuse potential and adverse effects. 1