Why are breasts different sizes?

During puberty, breasts don't always receive identical amounts of the hormone that makes them grow. Why does this happen, and how common is perfect symmetry anyway?

Double D Bra Size: Understanding DD Cup Size, Boobs and Breasts Size - HauteFlair

What Does My Bra Size Actually Mean?

Rubies Custom Bras: Normalizing Asymmetrical Uneven Breasts. Bespoke Bras Made For Different Cup Sizes

Why Do We Get So Much Pleasure From Symmetry?

Why Breasts Are Sometimes Uneven

The Same Bra Cup May Look Different Based On Band Size – PerfectDD

Breast Augmentation Size Chart - Implant Sizes and Cup Sizes

Why your breasts are not the same size

Stuff Mom Never Told You Podcast

EPBOT: Everything You Never Knew You Needed To Know About Bras

Learn About What the Smallest Bra Size Is

Sister Sizes: The Bra Secret Every Person Should Know – Sister Sizes & Equivalent Bra Size Chart – ThirdLove

Is It Normal to Have Different-Sized Breasts? - GoodRx