I'm curious about collagen care.

As the title suggests, what exactly is collagen care? As we age, our skin loses elasticity, so we naturally try to replenish collagen. There are ingestible and topical forms, but I've heard that topical applications aren't effective for replenishing collagen. Does a dermatology clinic actually offer a separate collagen care service? I usually think of collagen as just occasionally buying things like pig's trotters to eat. I figured it would be better to get it from food. However, when I search for "collagen care," nothing really comes up, so I'm curious what it actually is. If there is such a service at a dermatology clinic, I'd like to know about the cost and treatment duration. While there are various treatments for improving skin elasticity, collagen seems to have a particularly compelling appeal. You know how just a little bit of elasticity can make you look a few years younger?