Is Drinking Milk at Night Healthy? Separating Fact from Folklore

January 12, 2026 •

3 min read

According to the Centers for Disease Control and Prevention (CDC), over one-third of U.S. adults report not getting enough sleep, leading many to seek natural remedies like a warm glass of milk. But beyond the cozy tradition, is drinking milk at night healthy, and what does the science say about its effectiveness?

Quick Summary

The practice of drinking milk at night can offer benefits like promoting sleep through compounds such as tryptophan and melatonin, alongside a comforting ritual. However, factors like lactose intolerance and the potential for digestive discomfort or unwanted calories should be considered based on individual health needs.

Key Points

Tryptophan and Melatonin: Milk contains tryptophan, an amino acid that serves as a precursor to the sleep-regulating hormones serotonin and melatonin.
Psychological Comfort: The ritual of drinking warm milk can create a soothing, calming effect that signals to the body it is time to relax and sleep.
Calcium's Role: Calcium in milk aids the brain's synthesis of melatonin and supports muscle relaxation, both of which can enhance sleep quality.
Digestive Risks: For individuals with lactose intolerance, consuming milk at night can cause significant digestive distress and discomfort that disrupts sleep.
Calorie Considerations: Drinking milk at night adds to daily calorie intake, and for those managing weight, this should be taken into account to avoid gradual weight gain.
Temperature Preference: While both warm and cold milk offer the same nutrients, warm milk may be more effective for inducing relaxation due to its comforting, soothing nature.

The Science Behind Bedtime Milk

For generations, a warm glass of milk before bed has been a trusted ritual for winding down. Research suggests that milk contains components that may influence sleep, though individual responses can vary.

Tryptophan and Melatonin Production

Milk contains tryptophan, an amino acid the body uses to produce serotonin and melatonin. These are hormones that help regulate mood and sleep. Consuming tryptophan with carbohydrates may increase its availability to the brain. Some studies also indicate that milk produced at night may have higher natural melatonin levels.

Calcium's Role in Relaxation

Calcium in milk is essential for nerve function and assists the brain in using tryptophan to make melatonin. Calcium deficiency has been linked to sleep disturbances. The mineral also helps regulate muscle contractions, which can support physical relaxation.

Psychological Comfort and Habit

The routine of drinking a warm beverage like milk can be psychologically comforting and signal to the brain that it's time to rest. This ritual can reduce anxiety and improve sleep hygiene for some individuals.

Potential Benefits of a Nightcap

Incorporating milk into a balanced nighttime routine may offer several advantages:

Promotes Better Sleep: Tryptophan, melatonin, calcium, and the calming ritual can contribute to faster sleep onset for some.
Supports Muscle Recovery: Milk contains casein protein which provides a slow release of amino acids, potentially aiding muscle repair overnight.
Boosts Nutrient Intake: Milk is a source of essential nutrients like calcium, vitamin D, and potassium.
Reduces Stress: The calming effect and presence of tryptophan may help lower stress before bed.

The Possible Downsides

Drinking milk at night may not be suitable for everyone due to potential negative effects:

Digestive Issues: Lactose intolerance or dairy sensitivity can cause gas, bloating, and discomfort that disrupt sleep. Slower nighttime metabolism may also affect digestion.
Weight Management: Milk contains calories, which could contribute to weight gain if they result in exceeding daily calorie needs.
Acid Reflux Concerns: Lying down after drinking milk can worsen GERD symptoms in susceptible individuals.
Increased Mucus: Some people report increased mucus from dairy, which could affect breathing, though scientific evidence is limited.

Warm vs. Cold Milk at Night

The preference for warm or cold milk before bed is often personal, as the nutritional content is the same. The difference lies in the experience.


Feature	Warm Milk	Cold Milk
Effect on Body	Soothing and relaxing; may calm the nervous system.	Refreshing; could increase alertness for some.
Psychological Impact	Provides comfort and reinforces bedtime routine nostalgia.	Lacks the warmth, relies only on nutrients for sleep aid.
Digestion	Generally easier to digest for most.	Can be harder to digest for some and may worsen constipation.
Scientific Backing	Most milk and sleep studies use warm milk.	Evidence is less focused on temperature; nutrients are in both.

Alternative Bedtime Beverages

For those who cannot or prefer not to drink dairy, several alternatives may promote relaxation:

Herbal Teas: Chamomile and lavender teas are known for their calming properties.
Tart Cherry Juice: Contains natural melatonin and tryptophan.
Fortified Plant-Based Milks: Options like almond, soy, or oat milk fortified with calcium and vitamin D offer nutrients, though often with lower tryptophan than dairy milk.

Conclusion: Is Drinking Milk at Night Healthy?

For many, drinking milk at night is a healthy practice that promotes relaxation and potentially better sleep through its tryptophan, melatonin, and calcium content, along with the comforting ritual. However, it is not universally beneficial. Individuals with lactose intolerance or digestive issues should be mindful of potential discomfort, acid reflux, or calorie concerns. The best approach is to consider your own body's response and maintain overall healthy sleep habits. If you have persistent sleep problems, consult a healthcare professional.

For more information on the link between dairy and sleep, you can refer to relevant studies published by the National Institutes of Health.(https://pmc.ncbi.nlm.nih.gov/articles/PMC10229376/)

Frequently Asked Questions

Yes, for many people, milk can aid sleep. It contains tryptophan, which helps the body produce melatonin and serotonin, hormones that regulate sleep. The psychological comfort of the warm beverage also helps many to relax.

Drinking milk at night can contribute to weight gain if the calories add to an overall surplus. However, a single glass is not a significant source of calories. Weight gain depends on your total daily intake, not just when you drink milk.

The nutritional content is the same in both. However, warm milk's soothing temperature can provide a psychological benefit, promoting relaxation more effectively for some individuals. For others, it comes down to personal preference.

Side effects can include digestive issues like bloating, gas, or diarrhea, especially for those with lactose intolerance. It may also worsen acid reflux symptoms and, for some, could contribute to mucus production.

It's best to drink milk about 30 to 60 minutes before bedtime. This allows your body some time to begin digestion before you lie down, potentially reducing any discomfort.

Yes. A recent study suggests that sleep disruptions and nightmares can be linked to the gastrointestinal distress caused by lactose intolerance, indicating the symptoms of intolerance can directly affect sleep quality.

Yes, alternatives like herbal teas (chamomile, lavender) and tart cherry juice contain compounds that can help promote relaxation and sleep. Fortified plant-based milks can also provide some sleep-supporting nutrients.