Why Sunscreen Is Not Enough
You apply it every morning. SPF 30 or 40, maybe even 50, broad-spectrum, reapplied after swimming. You are, by any reasonable measure, doing everything right. And yet the science is unambiguous: UV damage continues to accumulate inside your skin even when you follow every recommendation to the letter. This is not a reason to stop wearing sunscreen — it is an essential tool, and you should keep using it. But it is a reason to understand what sunscreen actually does, and more importantly, what it cannot do.
What Sunscreen Actually Does
Sunscreen works at the surface of the skin. Its filters — whether chemical absorbers or physical reflectors like zinc oxide — intercept ultraviolet photons before they penetrate the outermost layers. That interception is genuinely valuable: it substantially reduces the UV dose your skin receives, lowers your risk of sunburn, and over a lifetime makes a measurable difference to skin ageing and cancer risk.
But the word to focus on is reduces, not eliminates. An SPF 50 sunscreen, correctly applied, blocks approximately 98% of UVB rays — which sounds reassuring until you invert that figure. Two per cent of UVB still reaches your skin. In a full day outdoors, under a strong sun, that is a meaningful photon load. And for UVA — the longer-wavelength radiation that penetrates far deeper into the dermis — even broad-spectrum sunscreens offer comparatively weaker and less standardised protection. UVA does not cause the sunburn that SPF measures; it reaches the living tissue beneath, and it does so whether or not you remembered your morning routine.
The SPF number, in short, is a measure of filtered dose. It says nothing about what happens to the UV that gets through.
What Happens Inside the Skin
When ultraviolet photons penetrate the skin, they do not simply pass through harmlessly. They interact with cellular structures and trigger a cascade of chemical events. The most immediate is the generation of reactive oxygen species — unstable molecules more commonly called free radicals — that react destructively with proteins, lipid membranes, and DNA. This process, oxidative stress, is one of the primary mechanisms through which UV exposure drives both photoageing and skin cancer risk.
Of particular concern is what happens at the mitochondrial level. Mitochondria — the energy-producing organelles inside every skin cell — carry their own DNA, and that mitochondrial DNA (mtDNA) is unusually vulnerable to UV-induced damage. Unlike nuclear DNA, which has well-developed nucleotide excision repair pathways capable of correcting UV photoproducts, mtDNA lacks these repair mechanisms almost entirely. Research published in Genetics confirms that for mammals, there is no known repair mechanism for photodamage in mitochondrial DNA — damaged mtDNA is simply degraded. Over time, this selective vulnerability means that even sub-threshold UV exposures accumulate into a pattern of mitochondrial dysfunction that compromises cellular energy production and accelerates the ageing process in skin.
A 2025 study published in the International Journal of Cancer by scientists at the International Agency for Research on Cancer (IARC) estimated that 83% of all new melanoma cases worldwide in 2022 — approximately 267,000 out of 332,000 — were attributable to ultraviolet radiation exposure. The scale of that figure reflects decades of cumulative cellular damage, much of it occurring in people who were not reckless with sun exposure. Sub-threshold damage, repeated year after year, adds up.
The Antioxidant Defence — and Why It Gets Overwhelmed
The human body is not defenceless. Skin maintains a sophisticated antioxidant system specifically designed to neutralise the free radicals generated by UV exposure. The key enzymes are superoxide dismutase (SOD), catalase, and glutathione peroxidase — each targeting different types of reactive oxygen species and working in concert to keep oxidative stress in check. Vitamin C (ascorbate), vitamin E (alpha-tocopherol), and carotenoids derived from diet add further capacity to this system.
The problem is one of demand outpacing supply. Research published in Redox Report documents that UV exposure depletes glutathione, ascorbate, SOD, catalase, alpha-tocopherol, and ubiquinol measurably and dose-dependently. High UV loads — the kind accumulated during ordinary outdoor activity all over the world — draw down these antioxidant reserves faster than the body can regenerate them. The depletion is most pronounced in the epidermis, exactly where UV photons arrive first.
Diet-derived antioxidants help, but face a bioavailability problem. Vitamin C consumed at the table must travel through the bloodstream and diffuse into skin tissue; by the time it reaches the deeper dermal layers — let alone the mitochondria inside individual cells — the concentration has fallen substantially. Eating well is important. It is just not a precision instrument for protecting mitochondria from UV-induced oxidative stress. However, a topically applied lotion of a uniquely precise formulation can provide the required protection.
There is also a broader environmental context worth noting. ESA's Swarm satellite constellation has tracked a significant and continuing weakening of Earth's geomagnetic field, particularly in a growing region over the South Atlantic. The geomagnetic field is one of the planet's primary shields against incoming cosmic and solar radiation; as it weakens, ground-level radiation exposure gradually increases. This is a slow-moving trend, not a cause for immediate alarm, but it reinforces the point that the UV and radiation environment we are managing is not static — it is, if anything, incrementally more demanding than it was a generation ago.
The Missing Layer of Protection
Put the picture together and a clear gap emerges. Sunscreen reduces the UV dose reaching your skin surface — and that matters enormously. A good diet with antioxidant-rich foods provides some systemic support. But neither addresses the specific problem of oxidative damage occurring at the mitochondrial level inside your skin cells, in real time, every time UV photons penetrate the surface layer.
What is needed — and what the science is beginning to show is achievable — is the targeted delivery of antioxidant protection to where UV damage actually occurs: not at the skin's surface, and not in the general circulation, but at the level of the mitochondria inside UV-exposed cells. Research into mitochondria-targeted photoprotection is an active and rapidly evolving field in photobiology. The tools to act on this science are catching up with the understanding of the problem.
We have been following this science closely for some time. Something is coming — a new approach to photoprotection that addresses this missing layer directly. We are not ready to say more than that yet, but we will be soon.
If you would like to be among the first to know when this new approach becomes available, please enter your details in the form you'll find on this page at the top of the right hand column. No spam — just one notification when we are ready. You have already taken sun protection seriously. This is the next step.
