Biology, genetics, chemistry, dermatology, research.

Hair & Science

Accessible science with credible sources — easy to read, backed by research.

Evidence-based Beginner

Hair Biology

Why does hair curl?

The shape of a strand is decided before it ever leaves the scalp. Follicles, keratin, and genetics — explained in plain language.

By Saerin Hwang · 8 min read

Evidence-based

Hair & Science

The genetics of hair texture

Why there isn't a single switch marked CURLY.

Coming soon

Evidence-based

Hair & Science

Inside the hair follicle

A tour of the small, complex structure that builds every strand.

Coming soon

More articles are being written. Subscribe to The Love Letter to hear when new pieces are published.