Your skin stopped producing the molecule β-sitosterol, which keeps your barrier thick enough to conceal your blood vessels.
When estrogen drops (which happens to every woman eventually), it triggers a chain reaction.
Your skin cells slow down production of β-sitosterol, the structural molecule that keeps your barrier thick.
Some women's skin slows down gradually, and their barrier stays relatively thick.
But for others, the research revealed that their barrier thins more rapidly.
Think of it like this:
If you took two pieces of fabric, one thick like denim, one thin like tissue paper, and held them over a red surface, which one would show the red through?
The tissue paper, obviously.
That's exactly what's happening to your face.
Without enough of this structural molecule, your skin becomes paper-thin, like tissue paper instead of denim.