Will Retin-A Thin the Skin and Cause Broken Blood Vessels?

Tretinoin cream (Retin-A) stimulates the production of collagen and thickens skin.  It does not thin skin.  It does give skin a rosy glow because it stimulates tiny new blood vessels to grow but they are not visible on the skin.  If, however, someone has rosacea and spider veins, tretinoin cream may be too harsh and can cause irritation with more reddening of the skin.

If tolerated, you can continue with your current regimen, including sunscreen, but do not use tretinoin cream during pregnancy.

Your P.A. isn't giving you sound advice.  Retin-A will not cause atrophy or thinning of the skin.  In fact, it actually acts to make the skin layers more robust, which is one of the reasons we like Retin-A micro for our cosmetic patients.  

You should be using sunscreen to prevent sun damage, which is one reason for blood vessels to show.  At 26, Retin-A micro is a good bet for your skin.

She does not know what she is talking about.

Retin A stimulates collagen and elastin remodeling and formation. The skin dermis will be thicker nicer and better.

Continue what you are doing