What is melatonin?

Melatonin is a hormone naturally produced by the pineal gland in the brain that helps regulate your sleep-wake cycle (circadian rhythm). As it gets dark, melatonin production increases, which signals to the body that it’s time to rest. When morning arrives, levels naturally drop, encouraging wakefulness. Stress, travel across time zones, late night screen use and shift work can all disrupt this cycle, leading to difficulty falling and staying asleep.

Clinical research supports that low dose melatonin can help reduce the time it takes to fall asleep and may improve sleep quality in some people. However, it is not a sedative in the traditional sense. It works more like a signal to your brain that it’s time to wind down, rather than forcing you under sedation.

Using melatonin

The effectiveness of melatonin acts in a subtle regulatory way. Its effectiveness depends on timing: taking it too early, too late, or in too high a dose can reduce benefits or even disrupt your rhythm further. It’s also important to pair any melatonin use with good sleep habits. Consistent bedtimes, a dark sleeping environment, reducing screen use before bed and limiting caffeine or alcohol late in the day can make a big difference. 

As of June 2025, melatonin  supplements in New Zealand have undergone regulatory changes that allow for it to now be supplied over the counter (i.e. without a prescription) in pharmacies, under defined dose and duration limits. 

Melatonin is generally considered safe for short-term use in adults but is not suitable for everyone. It should be used with caution (or avoided) by pregnant or breastfeeding women, those with autoimmune disorders or seizures, people on certain medications (e.g. anticoagulants, immunosuppressants), or those with severe liver or kidney disease.