Dull and tired looking: where the glow actually comes from

Glow has a physical definition. It is light reflecting evenly off a smooth, hydrated surface over an even layer of pigment, with good blood flow underneath. Dullness is any of those four slipping, and in midlife two hormones push on all of them at once.

Estrogen affects three of the four

Estrogen targets the keratinocytes that build the skin surface, the melanocytes that make pigment, the fibroblasts beneath, and the sebaceous glands.¹ It also supports blood vessel growth in skin.¹ As it declines, the skin becomes thinner and drier, so the surface is rougher and scatters light instead of reflecting it; pigment becomes less even; and the skin becomes less vascular, with less of the warmth that blood close to the surface gives a face.¹ Each of those on its own would read as "tired". Together they are what most women mean by dull.

Cortisol dries the surface

Stress hormones add the fourth. Cortisol reduces the lipids and structural proteins in the outer layer, lowers its hydration and increases water loss through it.² A dehydrated surface is a dull surface: the fine scale that lifts when skin is dry diffuses light. This is why dullness is worse after bad sleep and better after a holiday, before any product is involved.

Why it is "faster than age explains"

Sun and years dull skin slowly. Hormonal dullness moves on the hormone's timetable: postpartum, when estrogen drops in days; perimenopause, when it swings; a stressful year. The surface can look older in one season and recover some of it in the next, which is not how ageing behaves.

Put together

"Dull and tired looking" is a thinner, drier surface scattering light, less even pigment and less blood flow under it, all tied to falling estrogen, with cortisol drying the surface further.

What this means for a routine

The quickest change to the look of dull skin is water in the surface, which smooths it within days; the slower change is evening the look of tone. Cōpḍī's Prep carries five molecular weights of hyaluronic acid, snow mushroom and polyglutamic acid for layered hydration, grape seed for antioxidant support against dullness, and a shiitake and turkey tail mushroom complex that brightens and evens the look of tone; Plump adds niacinamide, tranexamic acid and licorice, which brighten and even the look of tone.