Breastfeeding Myth vs Fact: Does Breast Size Affect Supply—and Is “More Milk” Always Better?

Breastfeeding myths have a way of sounding like facts when you’re exhausted, recovering, and just trying to feed your baby. Two of the biggest ones show up early and stick around: breast size “predicts” supply, and having tons of milk is the ultimate goal.

Let’s talk about what’s actually true—and what matters most.

Myth #1: Breast Size Affects Milk Supply

You’ll hear this in different versions:

• “If you’re smaller-chested, you probably won’t make enough milk.”

• “Success depends on your anatomy.”

• “Bigger breasts = better supply.”

It’s easy to believe, especially if you’re already worried.

Fact: Size Doesn’t Determine Production

Breast size does not determine whether you’ll be successful with breastfeeding.

In real life, even smaller-chested moms can have an oversupply—yes, even moms with very small cup sizes can make more than enough milk. Breastfeeding success isn’t dictated by breast size, and supply challenges can happen in any body.

So if you’ve been side-eyeing your anatomy and assuming the outcome is already decided, take a breath.

That’s a myth.

Source: https://www.milkgenomics.org/?splash=do-larger-breasts-make-more-milk

Myth #2: More Milk Is Always Better

This one is everywhere—especially online:

• “I want as much milk as possible.”

• “A freezer full means you’re doing it right.”

• “Oversupply is a good problem.”

It sounds like a win, right?

Fact: Oversupply Isn’t Ideal

Oversupply isn’t automatically a victory. It can create its own challenges, and it can impact feeding in ways people don’t expect.

When milk comes too fast (fast-flow), baby may fill up quickly on the early, thinner milk and miss out on the richer, fatty milk that comes later in a feed. A helpful way to picture it:

• Oversupply can act more like skim milk—lots of volume, fast.

• What baby really needs is that heavier, richer, more satisfying “whole milk” part of the feeding.

That’s why stacks and bricks of milk in the freezer aren’t necessarily a good thing. It can look impressive, but it doesn’t always reflect balance—or an easier feeding journey.

What Matters Most: Balance

Here’s the heart of it:

• Breastfeeding is not a competition.

• Supply isn’t “better” just because it’s bigger.

• Your goal is not a freezer full—it’s a feeding rhythm that works for you and baby.

Balance matters more than a freezer full.

And it’s worth repeating: every breastfeeding journey is different. Some moms need help increasing supply. Some need help managing oversupply. Both are real. Both deserve support.

The Bottom Line

Myth: Breast size affects milk supply.
Fact: Size doesn’t determine production—even smaller-chested moms can have oversupply.

Myth: More milk is always better.
Fact: Oversupply isn’t ideal. Too much fast-flow milk can mean baby misses out on the rich, fatty milk they need.

Every journey is different—and support makes all the difference.