Quick answer

The studies behind this page give no separate melatonin amount for women; adult trials used 0.1 to 5 mg. Two things do differ. Women taking birth control pills had 4 to 5 times more melatonin in their blood after the same dose in one study, and research in pregnancy and breastfeeding is lacking.^1,2,3

Key facts

A 2016 safety review advises pregnant and breastfeeding women not to take melatonin until human studies exist.⁴
In the birth control study, the pill slowed the breakdown of melatonin by the liver enzyme CYP1A2.²
Several of the largest 2 mg trials enrolled people aged 55 and over.¹

The evidence applies to women too

Helps you fall asleep a little sooner on nights of occasional sleeplessness*^1,5,6

Moderate evidence

Pooled placebo-controlled trials show melatonin shortens the time it takes to fall asleep by about 4 minutes (17 studies, 284 people) to 7 minutes (19 studies, 1,683 people, doses of 0.1 to 5 mg). The effect is consistent but small, most trials were short, many enrolled people with diagnosed sleep problems, and the largest 2 mg trials used a slow-release tablet.

Amount studied: 0.1 to 5 mg, almost always taken in the evening

The grades on this site come from trials in adults in general. None of the sources used here reports results separately for women, and none sets a different amount for them.^1,5

Women may absorb more of each dose

In a study of 12 young adults, the share of an oral dose that reached the blood was about twice as high in women as in men: 16.8 percent against 8.6 percent on average.⁷

That was one small study, but it fits a wider pattern. Across pharmacokinetic studies, the share of a swallowed dose that reached the blood ranged from 9 to 33 percent.⁸

Birth control pills

In a study of 29 healthy adults given 6 mg of melatonin, those taking birth control pills had 4 to 5 times as much melatonin in their blood as those who were not, because the pill slowed its breakdown. Alertness did not differ.²

That finding comes from one pharmacokinetic study, not from an official drug warning, and none of the official sources checked for this page addresses it. If you take the pill or another hormone medicine, ask your pharmacist before taking melatonin.²

Pregnancy and breastfeeding

NCCIH says there has been a lack of research on the safety of melatonin in pregnant or breastfeeding women. A 2016 safety review advises them not to take it until there is.^3,4

NIH's lactation database adds that melatonin is a normal part of breast milk, with more at night, and judges short-term evening use of usual doses unlikely to harm a breastfed baby. It has no safety data on mothers taking it, though, and some experts advise against use while breastfeeding.⁹

Our Sleep formula's label tells pregnant or nursing mothers to consult a physician first. Our own advice is not to use it during pregnancy at all, because it also contains passion flower, which NCCIH says should not be used in pregnancy.¹⁰

Melatonin and age

The body's own night-time melatonin peaks in early childhood and falls with age. In a study of 367 people, average night-time blood levels were about 62 pg/mL at 15 to 20 years and 29 pg/mL at 70 to 90 years.⁷

Older adults are well represented in the evidence: several of the largest 2 mg trials enrolled people aged 55 and over.¹

Next-day drowsiness after 50

NCCIH says melatonin may stay active longer in older people and cause daytime drowsiness, and that guidelines recommend against it for people with dementia. Ask your doctor first, especially if you take other medicines.³

What's in ours

What’s in ours

Sleep: Melatonin, 2 mg per serving, from the label

Two capsules list 2 mg of melatonin, inside the 0.1 to 5 mg range of the adult trials.¹

Questions people ask

Is melatonin safe for women over 50?

Short-term use appears safe for most adults, and older adults were well represented in the 2 mg trials. But NCCIH says melatonin may stay active longer in older people, causing next-day drowsiness, so ask your doctor first, especially if you take other medicines.^1,3

Does melatonin affect periods or hormones?

The sources here do not report effects on periods in adult women. NCCIH notes that because melatonin is a hormone, supplements might affect hormonal development in children, including puberty and menstrual cycles, but that this is not known for sure.³

Can I take melatonin while on the pill?

Ask your pharmacist first. In one study, people taking birth control pills had 4 to 5 times more melatonin in their blood after a 6 mg dose, because the pill slowed its breakdown, though they did not feel less alert.²

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Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.