Morning breastmilk vs evening breastmilk

how is morning milk different from evening milk?

*As an Amazon Associate I do earn a small commission from products you purchase through my site, but it doesn’t affect the price you pay. I will never recommend a product unless I think you’ll love it!

When it comes to your sleep cycle, your body does more than just fall asleep and wake up! It begins preparing hours before those events by increasing or suppressing hormones. And those hormones flowing through your body also go into your milk. This means that your evening breastmilk and your morning breastmilk have different hormones in them.

morning breastmilk vs evening breastmilk

The hormones your baby gets from breastmilk make up one of the ways your baby develops his circadian rhythm. Cool right?

What goes on in the morning

About 2 hours before your normal waking time – never mind, moms with babies don’t have a normal waking time. Let me start over.

About 2 hours before your body thinks it might wake up, it stops making melatonin (a hormone that makes you sleep) and it begins to push more cortisol and adrenaline through your body.

It’s not exactly an adrenaline rush through your system, more like a gentle adrenaline stream.

The cortisol and adrenaline bring you into a lighter sleep state and make it easier to get out of bed. Even if it still sucks.

Morning breastmilk

When you first wake up, you gotta lotta milk! All night long, your body’s just been cooking up batches of it. And unless a hungry little someone was eating through the night, your boobs are ready to unload some of this milk!

But it’s not the same milk you had last night…

Morning breastmilk is pretty amazing stuff! It’s mostly foremilk and usually has that watery, blue tint. But the really cool thing about morning milk is that it’s got a little bit of your adrenaline and cortisol in it!

Like a little Mama-latte for your baby 🙂

Related Post: Breastmilk changes for baby’s needs

Getting those hormones in the morning helps your baby’s body learn that this is the time of day to be awake.

What goes on at night

When night time comes — about 2 hours before you usually go to sleep, to be exact — your body goes to work. It slows your digestive system and makes a small amount of melatonin and tryptophan. These two go together to promote healthy, restorative sleep.

As tryptophan and melatonin work their way through your body, they also go into your milk. And when your little one nurses before bedtime, he gets a small dose of them to help him fall asleep.

Parents should know that breastmilk in the evening contains more tryptophan (a sleep-inducing amino acid). Tryptophan is a precursor to serotonin, a vital hormone for brain function and development. In early life, tryptophan ingestion leads to more serotonin receptor development (Hibberd, Brooke, Carter, Haug, & Harzer, 1981). Nighttime breastmilk also has amino acids that promote serotonin synthesis (Delgado, 2006; Goldman, 1983; Lien, 2003). Serotonin makes the brain work better, keeps one in a good mood, and helps with sleep-wake cycles (Somer, 2009). So it may be especially important for children to have evening or night breastmilk because it has tryptophan in it, for reasons beyond getting them to sleep.


Should you label morning breastmilk & evening breastmilk?

The hormones in breastmilk that vary by time of day will help train your baby’s body to get a circadian rhythm in place. And they can really help your baby get back to sleep during a 2 AM feeding! But is it really necessary to label our breastmilk storage bags as AM and PM?

Should we avoid giving AM milk in the PM or giving PM milk in the AM?

Maybe. The hormonal effect is there. But it’s not strong enough to zonk out a wide-awake baby or make a sleepy baby hyper. But if your tiny one is already starting to wind down or come awake, it can be the little nudge they need in the right (or wrong 😬) direction.

Related Post: Breastmilk storage simplified-How to store breastmilk safely

There are really only 2 scenarios where I’d consider it worth your time to diligently label AM/PM and feed your baby according to those labels:

  1. If feeding morning breastmilk in the evening or vice versa makes a noticeable difference to your baby’s energy levels. If he’s extra sensitive to the hormones, you should label and feed based on pumping times.
  2. If more than half of your baby’s nutrition comes from expressed milk. After all, his circadian rhythm is evolving, and the hormones in your milk are part of the formula his body is using!

But if your baby only gets an occasional bottle of pumped milk and isn’t phased by getting milk that was pumped on the opposite side of the clock, then it’s not a big deal. You can just give him whatever milk you grab first.

In conclusion

Your body goes through a rhythm of hormonal changes throughout every day. Every hormonal shift in your body also creates the same hormonal shift in your milk. By breastfeeding, your baby’s body gets trained by your hormones to follow your circadian rhythm.

For most babies, the effects of the hormones are only a gentle push toward getting sleepy or waking up. So it isn’t to label your milk AM/PM and feed according to the time of day. It’s really only worth your time if your baby’s energy level visibly changes after a feeding or if most of his milk is pumped.

How diligent are you in labeling your pumped milk AM and PM? How strict are you about sticking to those times when you give your baby bottles? Do you notice a difference? Please comment below and share your experience!


Narvaez, D. F. Ph.D. (2013, March 11). Normal Infant Sleep: Night Nursing’s Importance. Retrieved from

1 thought on “Morning breastmilk vs evening breastmilk”

  1. Nicole's signature
  2. After about a month of breastfeeding/pumping, I began labeling my pumped milk. Instantly noticed a difference in our baby in the evenings. He’d settle down and sleep long stretches overnight! Although it might not work for everyone, it helped us tremendously.

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.