I always thought drinking warm milk before going to bed helps one fall asleep.

According to Dr.Oz's friend, it does

Dr. Oz talked with a sleep expert who said warm milk will help you fall asleep at night. The milk helps you fall asleep because it contains small amounts of tryptophan and melatonin, both of which help you sleep.

According to zocdoc.com it does

Your mother was right that drinking warm milk before bed can help you sleep. This is because milk contains tryptophan, which is an amino acid which helps induce sleep.

According to Art Spielman it does not

But when milk was tested, it failed to affect sleep patterns. “Tryptophan-containing foods don’t produce the hypnotic effects pure tryptophan does, because other amino acids in those foods compete to get into the brain,” explains Art Spielman, M.D., an insomnia expert and professor of psychology at the City University of New York.

According to an article published by Anahad O'Connor it's debatable

But whether milk can induce sleep is debatable, and studies suggest that if it does, the effect has little to do with tryptophan.

To have any soporific effect, tryptophan has to cross the blood-brain barrier. And in the presence of other amino acids, it ends up fighting — largely unsuccessfully — to move across.

One study by researchers at the Massachusetts Institute of Technology demonstrated this in 2003. The study, which was published in The American Journal of Clinical Nutrition, showed that eating protein-rich foods — like milk — decreased the ability of tryptophan to enter the brain.

  • 1
    Does tryptophan cause drowsiness? may be relevant. Milk is a fairly poor source of tryptophan. Getting a sleep-influencing dose of tryptophan (1+ grams), even if we discount the "amino acid competition" O'Connor and Spielman talk about, would require quite a lot (about 1.2 litres) of milk
    – Compro01
    Nov 27, 2013 at 14:26
  • 1
    I saw "Dr Oz" referenced and immediately thought this has to be wrong. This suggests it is more about a night time routine that encourages sleep more than anything in the foods: blogs.webmd.com/sleep-disorders/2008/01/… Dec 4, 2013 at 10:34
  • One of the symptoms of my milk allergy is drowsiness. Perhaps the source for this home treatment is actually a common mild allergy.
    – user11643
    Nov 23, 2017 at 8:09
  • Or maybe it is the melatonin that wasn't subjected in the only answer.
    – Communisty
    Nov 23, 2017 at 8:38

1 Answer 1


If milk induces sleep, it is not because of its effect on skin temperature (in the case of warm milk) or tryptohpan.

consuming milk as such is unlikely to induce sleep, as the amount of tryptophan present in milk is too small. Milk coupled with a carbohydrate food at bedtime can be a potential sleep aid.

having a glass of warm milk is unlikely to raise skin temperature enough to have any effect

  • Added reference for having a glass of warm milk in the gut is unlikely to raise skin temperature enough to have any effect. According to Progress in Brain Research, a sleep textbook published by the Netherlands Institute for Neuroscience in 2006, sleep is induced more rapidly when skin temperature rises. The two studies referenced show milk is a functional food for sleep when used in combination with LTPA and as a fermented product. Agree that sleeping aid differs from sleep quality improvement. Jul 17, 2015 at 4:10
  • Warm milk i.e. milk temperature in relation with sleep induction is already mentioned as a "myth" per the two blog references. My answer is only regarding the relation between milk and sleep, tryptophan mentioned in the summary of the question and not regarding its warmth. Jul 17, 2015 at 5:15
  • Fermented milk is a product of milk-which is why it is mentioned in the answer and consumption of milk and milk products along with LTPA is clearly mentioned in the first study. So both of these studies show a relation between milk and sleep. Jul 17, 2015 at 10:39

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