Reading the dry skin thread and it got me thinking about something I’ve been circling for a while, which is that “dry skin” in the post-menopausal context is probably two different things wearing the same label, and the intervention that works depends on which one you have. The two mechanisms I keep landing on: 1. Barrier lipid depletion. Ceramides, cholesterol, and free fatty acids in the stratum corneum drop with declining estrogen. The skin still holds water reasonably well at the surface but the lipid matrix is thinner, so anything that strips it (hot water, surfactants, retinoids) tanks the barrier faster than it would have at 40. 2. Transepidermal water loss. The skin loses water through the surface faster than the dermis can replenish it. Hydration sits below threshold even when nothing has been stripped. This is the one humectants (glycerin, hyaluronic acid, urea at low %) target, and it’s also the one that worsens with low humidity. These feel correlated but they aren’t identical, and the reason it matters is that the fixes diverge. Ceramide-forward moisturizers (the CeraVe / Epiceram type formulations) repair lipid matrix and won’t do much if your problem is mostly TEWL in dry winter air. Humectant-heavy products (hyaluronic serums, glycerin) pull water in but if the barrier is already shot they accelerate evaporation and the skin feels worse, not better, an hour later. Occlusives (petrolatum, lanolin) seal whatever is underneath, good or bad. What I’d actually want to know, and haven’t found a clean source on, is whether anyone has measured TEWL and ceramide ratios in post-menopausal skin separately, ideally with and without topical estrogen. The dermatology lit I’ve skimmed treats it as one bucket and the rec is always “moisturize more,” which is fine advice but doesn’t tell you which kind. Anyone tracked which type of product actually moved the needle for them? Curious whether the split shows up in lived experience.