Oxidative stress and your skin: what it does, what helps

Cut an apple in half and leave it on the chopping board. An hour later, the cut surface has turned brown. A bike that’s been left outside over the winter starts to rust. Two everyday scenes, one and the same reaction: oxidation. And it’s happening, quietly, in your skin too.

Free radicals – unstable molecules missing an electron – play the leading role. To stabilise themselves, they snatch an electron from a neighbouring molecule, damaging it in the process. Your body is prepared for this and has its own defence system of antioxidants ready to counteract it. If the balance is right, you won’t notice a thing. If the radicals gain the upper hand, this is known as oxidative stress.

If you read our recent posts, you have already met the term. UVA, infrared, visible light — different as they are, they all lead to the same point. Oxidative stress is the common thread behind premature skin ageing. Here is what it does, how your skin defends itself, and what you can actually control.

What happens in the skin during this process

Free radicals aren’t choosy. They attack anything that gets in their way – the cell’s genetic material just as much as its proteins or the fats in the cell membrane. But they cause the most trouble one layer deeper, in the dermis, where your connective tissue is located.

There, they cause twofold damage. Firstly, they take out those Enzymes: spicy, which act like tiny scissors to break down collagen and elastin – the MMPs. Secondly, they inhibit the very process by which the skin produces new collagen. That is the tricky part: more is broken down, whilst at the same time less is replaced.

Over the years, the connective tissue gradually thins out. This is accompanied by cells that go into a sort of ‘retirement’ and contribute very little, inflammation that simmers quietly in the background, and pigmentation that sets in more quickly. When we look in the mirror, this manifests as what we’re all familiar with: fine lines, a loss of firmness, a tired complexion, and the odd blemish here and there.

Your skin is fighting back – but its strength is waning

Your skin is not defenceless against free radicals. It mobilises its own defence force: protective enzymes such as superoxide dismutase and glutathione, commanded by a switch called NRF2, which ramps up production as soon as things get dicey.

The problem isn’t the system, but time. Over the years, this defence mechanism becomes sluggish, and when too many radicals advance at once, it simply overwhelmed. That’s why, as we get older, our skin needs more help from the outside – not because it’s giving up, but because a bit of support does it good.

There is a persistent misconception, and let’s clear that up straight away: it’s not about hunting down every single free radical. The body needs a certain amount of them as a signal, for example to trigger repair processes. The aim is to strike a balance, not to reach zero.

Where the radicals come from

Some of it is produced quite naturally, simply because your cells are burning energy. This naturally occurring component is always present, and that’s a good thing – you can’t do without it entirely.

The part you hold in your hand is more interesting. You’re already familiar with UVA, infrared and visible light as sources of free radicals that penetrate deep into the skin. Added to these are two that are less often discussed: city air, with its particulate matter and exhaust fumes, and cigarette smoke – one of the most potent sources of free radicals of all, affecting the skin both from the outside and from the inside.

The beauty of the phrase «in one’s hands» is that it leaves room for action. More consistently UVA protection, giving up cigarettes, cutting down on exhaust fumes a little wherever possible – this reduces the burden of free radicals before it even arises. Only then do antioxidants come into play.

From the crucible: what has actually been proven

When it comes to antioxidant skincare, there’s a lot of marketing hype about. Let’s stick to what the studies actually show – and that’s primarily a trio: vitamin C, vitamin E and ferulic acid.

Vitamin C (L-ascorbic acid) not only neutralises free radicals, it is also essential for building collagen. Combined with vitamin E, it quadrupled the skin's protection against UV damage in studies. Adding ferulic acid doubled that protection again to roughly eightfold — and measurably reduced UV-induced DNA damage. This protective effect was confirmed on living skin.

One point that is often overlooked: these serums are no substitute for sun cream. They work alongside it, trapping the UV rays that still manage to get through despite the cream.

And a practical tip, because vitamin C is a real diva: it breaks down quickly and is only effective in an acidic environment. Whether the jar actually contains what the label promises depends heavily on the formulation and light-proof packaging. Two other ingredients that have earned their reputation are niacinamide and the copper peptide GHK-Cu – although, in a poorly formulated product, GHK-Cu can actually have the opposite effect and even generate free radicals. Quality here is not a luxury, but a prerequisite.

On the plate: good, but with a clear limit

Your skin thrives not only on what you put on it, but also on what ends up on your plate. Carotenoids and polyphenols from fruit and vegetables enhance demonstrably the threshold, as UV radiation irritates the skin, and they trigger the same NRF2 defence mechanism that we discussed earlier. In a study involving people who work outdoors in a heavily polluted city, a polyphenol supplement even measurably reduced environment-induced oxidative stress.

The rule of thumb is delightfully simple: as many colours as possible on your plate.

• Berries – Blueberries, blackberries, raspberries: rich in anthocyanins and vitamin C
• Green tea: provides EGCG, one of the most extensively studied plant-based antioxidants
• Colourful vegetables – Carrots, sweet potatoes, pumpkin, tomatoes: carotenoids, including lycopene
• Dark leafy vegetables – Spinach, kale: lutein and vitamin C
• Nuts, seeds, avocado and good-quality olive oil: Vitamin E and healthy fats
• Dark chocolate, grapes, pomegranate: Polyphenols
• Rotten fish – Salmon, Mackerel: Omega-3 for silent inflammation

So far, so good. Now for the catch rarely mentioned in skincare guides. As effective as antioxidants from food are, high-dose pills can backfire. High-dose synthetic beta-carotene supplements actually increased lung cancer risk in smokers. Large reviews find no benefit from high-dose antioxidant supplements — and sometimes harm. The reason is simple: in food, these compounds come in low doses alongside natural co-factors. Isolated in mega-doses, a helper can turn into a pro-oxidant. Eat colourful foods — do not rely on pills.

What we do for that in the clinic

Some antioxidants can be delivered more specifically to where they are needed than cream and diet alone can achieve.

With NCTF mesotherapy, we deliver a cocktail of active ingredients straight into the skin — including glutathione, the body's master antioxidant, plus vitamins, amino acids, minerals, and coenzymes. A HydraFacial infuses antioxidants in its final step, when the skin is most receptive. And Dermalux uses red and near-infrared light to prompt cells to repair themselves.

What counts in the end

You won't get rid of oxidative stress completely – and that's not the goal anyway. What matters is keeping the burden low and strengthening your defences. Protect your skin from what creates free radicals, especially UVA rays. Give it well-made antioxidants from the outside. Eat the colours instead of swallowing pills. And give it the rest it needs, without which no repair can happen – sleep is more a part of skincare than many people think.

How much sugar is involved in this, incidentally, keyword glycation, is a story in itself – we'll tackle that in a separate post.

Unsure where your skin is at right now?

In a free AURA 3D skin analysis, we look into the deeper layers and find out where your skin most urgently needs protection and support. Book your free AURA 3D skin analysis in Zurich now.

Sources & Studies

The statements in this article are based on the following scientific publications:

1. Liu HM et al. (2023). Possible Mechanisms of Oxidative Stress-Induced Skin Cellular Senescence, Inflammation, and Cancer and the Therapeutic Potential of Plant Polyphenols. Int J Mol Sci. PubMed 36835162
2. Augello FR et al. (2024). Efficacy of an Innovative Poly-Component Formulation in Counteracting Human Dermal Fibroblast Aging by Influencing Oxidative and Inflammatory Pathways. Biomedical Sciences. PubMed 39335544
3. Lin FH et al. (2005). Ferulic acid stabilizes a solution of vitamins C and E and doubles its photoprotection of skin. J Invest Dermatol. PubMed 16185284
4. Murray JC et al. (2008). A topical antioxidant solution containing vitamins C and E stabilized by ferulic acid provides protection for human skin against damage caused by ultraviolet irradiation. J Am Acad Dermatol. PubMed 18603326
5. Baswan SM et al. (2021). Role of ingestible carotenoids in skin protection: A review of clinical evidence. Photodermatology, Photoimmunology and Photomedicine. PubMed 33955073
6. Corbi G et al. (2022). Association between beta-carotene supplementation and mortality: a systematic review and meta-analysis of randomized controlled trials. Front Med (Lausanne). PubMed 35928292