Melatonin: less is more

The melatonin aisle at any drugstore is dominated by 5mg, 10mg, and even 20mg tablets. Most of those doses are wrong — they're 10-30× the amount your pineal gland produces naturally, and the data we have suggests that higher doses produce worse sleep, not better.

What melatonin actually does

Melatonin is a sleep-onset signal, not a sleep-maintenance drug. Your body normally releases it in response to darkness, peaking 2-4 hours into your sleep cycle. Its job is to tell your circadian system "it's night now."

Taking exogenous melatonin nudges that signal earlier (or stronger, if your endogenous production is suppressed by light exposure or shift work). The therapeutic window is small — overshooting doesn't help you sleep more, it just floods receptors and produces side effects.

The 0.3-0.5mg evidence

Multiple sleep researchers (most notably Richard Wurtman at MIT) have shown that 0.3-0.5mg of melatonin is enough to raise serum levels to the physiological peak. Higher doses raise serum levels into a supraphysiological range that:

• Causes daytime grogginess the following morning
• Disrupts the timing signal (because the level stays elevated longer than your body expects)
• Can actually delay sleep onset on subsequent nights as receptors downregulate

In studies comparing 0.3mg vs 3mg vs 5mg melatonin for sleep onset, lower doses consistently performed as well or better, with fewer next-morning side effects.

How to actually use it

• Dose: 0.3-0.5mg, not 5mg. If you've been taking 5mg, try cutting your tablet in tenths or switching to a 0.3mg sublingual.
• Timing: 30-60 minutes before your target sleep time, not "when you get into bed."
• For jet lag (eastbound): Start melatonin in the new time zone at the new bedtime for 3-5 nights.
• For jet lag (westbound): Often unnecessary — staying awake is the bigger problem.
• For shift work: More complicated. Talk to a clinician — shift-work disorder usually needs more than just melatonin.

What melatonin won't fix

• Sleep maintenance insomnia (waking at 3am and not falling back asleep) — melatonin is an onset drug, not a maintenance drug.
• Sleep apnea (which masquerades as insomnia in lots of patients).
• The kind of insomnia where you're anxious about not sleeping, which makes you not sleep, which makes you more anxious. That's a CBT-i problem, not a pill problem.

What to try instead, when melatonin isn't enough

For sleep-onset insomnia: low-dose doxepin (3-6mg), low-dose trazodone (25-50mg), or behavioral interventions (CBT-i has better long-term outcomes than any sleep drug).

For sleep maintenance: ramelteon, or addressing the underlying cause (caffeine timing, alcohol, stress, hormones, sleep apnea).

For jet lag specifically: melatonin remains the most evidence-based intervention, but the dose is still 0.5mg, not 5mg.

The bottom line

If you're taking 5mg or 10mg melatonin every night and feeling groggy in the morning, the fix is almost certainly to take less, not to take more or to add something else. The drugstore aisle is selling you confidence, not pharmacology.

Editorial content on a Relyv.ai demonstration site. Fictional author. Not medical advice.