Collagen supplements are widely purchased but hotly debated. Here we set out the mechanistic argument against them, what the clinical evidence nonetheless shows, and what cautious support looks like in practice.

Patients sometimes arrive having invested significantly in skincare and wondering whether aesthetic treatment adds anything meaningful. Others have had injectable treatments for years without giving their skincare any serious thought. Both groups are missing half of the picture.

The evidence converges consistently on three interventions as the foundation of any serious skincare routine: a topical vitamin C in the morning, a broad-spectrum SPF as the final morning step, and a retinoid in the evening. Everything else is supplementary. Here is the practical guide to choosing and using each one well.

The degree of dehydration required to produce visible changes in the skin only occurs during severe dehydration. You would be desperately thirsty and almost certainly unwell before your skin started looking dehydrated in any clinically meaningful sense. Drinking more water for better skin is one of the most repeated pieces of beauty advice — and one of the least supported by evidence. Here is what the science actually says, and what actually works instead.

New skincare ingredients arrive with impressive science and impressive marketing in roughly equal measure. Before examining any of them on their own terms, one question matters more than any other: does it actually penetrate the skin barrier in a biologically active form, in sufficient concentration, to reach the tissue where it is supposed to work?

Retinoids have accumulated an evidence base that no other topical skincare ingredient comes close to matching. They stimulate collagen production, inhibit its breakdown, accelerate surface renewal, and improve skin barrier function. No newer ingredient has been studied as thoroughly, over as long a period, or with as consistently impressive results. They may be promising. Retinoids are proven.