This article is part of a special issue investigating key questions about skincare. Find the full series here.

Our skin inevitably loses some of its elasticity as we age. In the past, the main weapon against the wrinkles and sags – for those who could afford it – was to go under the surgeon’s knife. Today, there are a wealth of less invasive alternatives that promise to firm up and rejuvenate our skin – everything from Botox injections to devices that blast light or ultrasound into the skin, and even “vampire” facials, where blood extracts are injected into the face.

Given that healthy skin brings wider health benefits, do these “tweakments” rejuvenate from the outside in? “The question is, is this just vanity or are you doing anything that’s going to help your future self?” says dermatologist Clare Kiely at Guy’s and St Thomas’ Hospital, London. “It depends on the type of treatment.”

Lost elasticity

Ageing comes with many transformations, but the primary cause of our wrinkles is a reduction in collagen and elastin, proteins that provide firmness and elasticity. Treatments such as Botox – injection of botulinum toxin to prevent muscles contracting – will do nothing to stop these changes, though they can be an effective way to prevent frown lines when injected into certain facial muscles. Likewise, injections of gel-like substances called dermal fillers beneath the skin can smooth wrinkles and add volume to sagging tissue, but don’t address the underlying structural changes, and come with risks.