10 Things That Affect Your Breast Milk Supply (That No One Tells You!)

If you’re breastfeeding or planning to, you’ve probably heard a few things already about how breast milk supply works. But did you know that some of the things that impact your breast milk supply might not be so obvious? Don’t worry, I’ve got your back. As a midwife of well over a decade and a mum of four, I’ve done my homework and bundled up all the information here for you.

As a midwife, I see new mums all the time worrying about their milk supply – and it’s no wonder, with so much conflicting advice floating around. So I wanted to share 10 lesser-known (but super important) things that can affect how much milk you’re making.

Let’s dive in…

1. Baby’s latch

Even a teeny-tiny latch issue can have a knock-on effect. If your baby isn’t latching properly, they might not be removing milk effectively and that tells your body to make less of it. If something doesn’t feel right, ask your midwife, health visitor or a lactation consultant to check.

2. How often you feed

Milk supply works on demand; the more you feed, the more your body gets the memo to keep producing. Don’t worry if it feels like your baby wants to be on the boob all the time, especially in the evening/ night. That’s called cluster feeding, and it’s completely normal.

Cluster feeding is your baby’s way of putting in a little milk order for the next day. It usually happens in the first few weeks and during growth spurts. According to the NHS and UNICEF Baby Friendly guidelines, babies feed frequently to help build up your supply – because breast milk is made on demand. Your baby isn’t just snacking for fun – they’re working with your body to get everything just right.

It can feel exhausting (and a bit never-ending), but it’s temporary. Think of it like your baby sending your body a memo that says: “More milk, please!”

3. Stress

Easier said than done, I know but your mental health absolutely plays a role. High stress can affect your let-down reflex and overall milk flow. Deep breaths, gentle walks, and accepting support can go a long way.

4. Hydration

You don’t need to chug litres of water, but keeping a bottle handy and sipping regularly really helps. Breastfeeding is thirsty work!

5. Certain medications

Some medications, even over-the-counter ones, can reduce your milk supply. Always check with your GP or pharmacist if you’re taking something new.

6. Hormonal birth control

Some hormonal contraceptives (especially those containing oestrogen) can interfere with your milk supply. It’s worth chatting with your doctor about breastfeeding-friendly options.

7. Skipping night time feeds

Your prolactin levels (the milk-making hormone) are highest at night so those sleepy feeds really do matter in the early days. Yes, it’s tough, but it makes a difference.

8. Supplementing with formula too early

Now this is never about shame or guilt – fed is best, always – but if you’re trying to build your breast milk supply, adding formula early on can reduce the stimulation your body gets to make more milk. It links back to what I said in point two.

9. Illness or fatigue

Your body is working hard to recover and make milk, so if you’re unwell or totally wiped out, it might dip your supply. Rest as much as you can and let others look after you for a change.

10. Your mindset

Yes – really. Confidence matters more than you think. If you’re feeling like “I can’t do this,” it can affect everything from your let-down to how often you feed. Be kind to yourself. You’re doing amazing.

A Whole-Body, Whole-Mind Thing

If you’re wondering how to boost your breast milk supply, remember it’s not just about food and water (though those matter too!). Your mind, your stress levels, your baby’s latch, and your own wellbeing all play a role.

If you’re ever unsure, worried, or just need a bit of a cheerleader in your corner, speak to your midwife or a lactation consultant. You don’t have to do it alone.

If you liked this post, take a look at 5 Items to help on your Breastfeeding Journey.