Sun Damage & Photoaging

Unlike the skin's natural aging process, photoaging is caused specifically by cumulative exposure to UV radiation, which penetrates skin and damages the collagen and elastin fibres that keep it firm and smooth, while also disrupting pigment-producing cells, together producing the fine lines, rough texture, and uneven tone associated with sun-damaged skin.

Because this damage is cumulative and driven by an external cause rather than an internal clock, daily broad-spectrum protection is the most effective way to help protect against it. A review of mineral UV filters describes how zinc oxide works by sitting on the skin's surface and physically reflecting UVA and UVB rays before they can cause that damage.

Photoaging accounts for the large majority of visible skin ageing that most people attribute to time alone, a distinction supported by the marked difference commonly observed between sun-exposed skin (like the face and hands) and habitually covered skin, such as the underside of the upper arm, even in the same person at the same age.

UV damage is cumulative and largely irreversible once it has occurred, which is why protection is considered more effective than trying to correct the visible signs later. Daily broad-spectrum SPF, reapplied through the day during real sun exposure, remains one of the most evidence-backed ways to help slow further photoageing, alongside any other skincare step.

Zinc oxide and titanium dioxide, the two most commonly used mineral filters, work by sitting on skin's surface rather than being absorbed, physically reflecting and scattering UV radiation before it penetrates, a mechanism that also makes them generally well tolerated by sensitive or reactive skin compared with some chemical filter alternatives.

In practice, that means making daily SPF non-negotiable regardless of weather or season, since UV exposure accumulates on cloudy days and through windows too. Consistent protection does more than anything applied after the damage has already occurred.