"I can't sleep, maybe I should try melatonin?" Easily available at pharmacies and online, melatonin is one of the most commonly misused supplements. Used right, it's powerfully effective. Used wrong — which most people do — you get no benefit and only side effects.
What melatonin is
Melatonin is a hormone naturally secreted by the pineal gland. Secretion starts when light dims, peaks at 2–4 AM, and falls when morning sunlight hits. The hormone signals the body that it's nighttime — it doesn't directly create sleep but sets when sleep should happen.
This is the source of the biggest misconception. People treat melatonin like a sleeping pill, when it actually functions like a clock.
Optimal dose — surprisingly small
Most over-the-counter melatonin contains 3–10 mg. But research shows the most effective dose is 0.3–1 mg. Beyond that, more does not increase the effect — but it does increase next-day grogginess and other side effects.
| Dose | Effect | Side effects |
|---|---|---|
| 0.3 mg | Sufficient for older adults | Almost none |
| 0.5–1 mg | Optimal for most adults | Very few |
| 3–5 mg | Same effect as 1 mg | Next-day drowsiness, headache |
| 10 mg+ | Possibly less effective than 1 mg | Headache, nausea, vivid dreams |
The "more is more" intuition does not apply to melatonin. The pineal gland's natural output is around 0.3 mg. Supplementing slightly past that is the most natural fit.
Optimal timing — not before bed, but 4–6 hours before
The most common mistake: "Take it 30 minutes before bed when I can't sleep." That misunderstands how melatonin works. It is not a fast-acting sleep drug — it's a tool to advance or delay your circadian clock.
Naturally, melatonin starts secreting about 2 hours after dark and peaks 4–6 hours later. To mimic that curve, take supplemental melatonin 4–6 hours before your target bedtime.
Example: want to sleep at 11 PM → take it at 5–7 PM.
When it works — appropriate uses
Where melatonin shines:
- Jet lag (especially eastbound flights): take 4–6 hours before local bedtime for several days after arrival. Most clearly helpful eastbound.
- Delayed Sleep Phase Syndrome (DSPS): helps shift forward the bedtime of people who naturally fall asleep at 3–4 AM.
- Shift work: 1 mg taken 30 minutes before sleeping during the day after a night shift.
- Age-related natural deficiency: pineal output decreases with age; supplementation can help in those over 60.
When it doesn't work — inappropriate uses
- General insomnia (stress-driven, caffeine-driven): melatonin won't override the same day's circadian state — fix the root cause.
- Daily use: not addictive, but effect can wane. 3–4 days per week is recommended.
- Short jet lag (1–2 hours): 1–2 days of natural adjustment is enough — melatonin unnecessary.
- Pregnancy, breastfeeding, children: insufficient safety data — physician consultation required.
Buying melatonin in Korea
In Korea melatonin is classified as a prescription medication. Many people import OTC versions from the US (NOW Foods, Natrol, etc.).
What to watch for:
- Dose: pick 1 mg or less. 5 mg, 10 mg is too much.
- Form: immediate-release recommended. Sustained-release mimics the natural curve better but is harder to adapt to initially.
- Quality: USP-verified, NSF, or GMP-certified products are safer.
- Liquid form: useful when you need precise low doses (0.3 mg).
The alternative — boost natural melatonin
Before reaching for the supplement, build the conditions for natural release.
- Dim lights an hour before bed: signals the pineal to start releasing.
- Morning sunlight: schedules melatonin release that night, 14–16 hours later.
- Melatonin-containing foods: cherries (especially tart cherries), walnuts, milk contain small amounts. Modest effect, good as adjunct.
- Magnesium: aids melatonin synthesis. 200–400 mg an hour before bed.
Conclusion — use it as a tool, not a crutch
Melatonin is a powerful tool when used right and an expensive placebo when used wrong. It only works at the right dose (0.3–1 mg), the right timing (4–6 hours before bed), and in the right context (jet lag, shift work, phase delay). For ordinary insomnia, fix caffeine cutoff, bedroom environment, and light exposure first. Supplements are the last resort, not the first.
