Quick Answer

What is melatonin and how does it work?

Melatonin is a hormone produced by your pineal gland that signals darkness to your body — it doesn't cause sleep directly but opens your 'sleep gate' by lowering core temperature and reducing alertness. Production begins 2-3 hours before your natural bedtime and is suppressed by light exposure.

Melatonin is often called the 'sleep hormone,' but this is misleading. It's actually a 'darkness hormone' — its job is to signal to your body that night has arrived, opening the window for sleep without directly sedating you.

How Melatonin Works

1. As evening light dims, your suprachiasmatic nucleus (SCN) signals the pineal gland 2. Pineal gland converts serotonin → melatonin and releases it into the bloodstream 3. Melatonin binds to receptors throughout the body, triggering: - Core temperature decline (vasodilation in extremities) - Reduced alertness and cognitive drive - Shift toward parasympathetic nervous system dominance 4. You enter the 'sleep gate' — a window where sleep onset becomes easy 5. Melatonin stays elevated for 8-10 hours, then is suppressed by morning light

Melatonin Timing by Chronotype

Lions: Melatonin onset ~8:00 PM (earliest), peak ~11 PM, cleared by 5:30 AM Bears: Melatonin onset ~9:30 PM, peak ~12:30 AM, cleared by 7:00 AM Wolves: Melatonin onset ~11:00 PM (latest), peak ~2:00 AM, cleared by 9:00 AM Dolphins: Melatonin onset irregular, often blunted amplitude (lower peak levels)

What Suppresses Melatonin

→Bright light (especially blue wavelengths 460-480nm)
→Screen use within 2 hours of bedtime
→Overhead lighting in the evening (>100 lux)
→Late-night exercise (raises core temperature)
→Alcohol (disrupts melatonin release timing)

Melatonin Supplements: What the Science Says

For jet lag: Effective. Take 0.5-3mg at the destination bedtime for 3-5 days.

For sleep onset delay: Mildly effective at low doses (0.5mg) taken 2-3 hours before desired bedtime (not at bedtime — you're mimicking natural onset).

For general insomnia: Weak evidence. Melatonin isn't a sedative; if your insomnia is caused by anxiety, pain, or poor sleep hygiene, melatonin won't help.

Dose matters: Most supplements (5-10mg) are 10-20x physiological levels. Start at 0.3-0.5mg. Higher isn't better — supraphysiological doses can desensitize receptors and cause next-day grogginess.

Natural Ways to Boost Melatonin

1. Dim lights progressively after sunset (use warm-tone bulbs <2700K) 2. Get bright morning light (resets the clock so evening melatonin arrives on time) 3. Eat tryptophan-rich foods (turkey, eggs, nuts) — serotonin precursor 4. Maintain consistent sleep timing (irregular schedules blunt melatonin amplitude) 5. Keep bedroom completely dark (even small lights suppress production)

The Dim Light Melatonin Onset (DLMO) Test

Researchers measure circadian phase using DLMO — the time melatonin first appears in saliva under dim light conditions. This is the most accurate way to determine your chronotype, and it explains why two people with the same bedtime can have very different sleep quality (their melatonin timing differs).

Our free diagnostic estimates your melatonin onset timing based on chronotype indicators and calculates your ideal sleep gate in under 2 minutes.