By the age of 25 and over the skin will exfoliate every 28 days or so. And at 30, every 40-42 days. The resulting build up of dead skin cells can leave the skin looking dull.
The team observed that the combined training regimen led to significantly greater reductions in insulin resistance (as compared to resistance training alone), and was also associated with greater improvements in functional limitations (as compared to aerobic exercise alone).
With the estrogen drop, production and repair of the skin’s collagen and elastin also falls, which can cause a dryer, duller complexion. Estrogen also stimulates fat deposits. As these levels shrink, fat deposits become redistributed, and that causes the loss of supportive fat in the skin of the face. This allows sagging wrinkles to appear.
Retinol enhances the skin's barrier function, aids in collagen production, regulates oil production, reduces skin dryness, and increases skin oxygenation. Topical steroids like cortisone will thin the skin when used for prolonged periods. Retinol will actually thicken thin skin.