They are heard everywhere in beauty and health discussions, often associated with the word "antioxidant" without further explanation. Free radicals have become a marketing concept before being understood for what they truly are: biological molecules with measurable effects on cellular aging. Understanding their mechanism means understanding why certain active ingredients make a real difference for the skin, and others don't.
What exactly is a free radical?
A free radical is a molecule or atom that has an unpaired electron in its outer shell. This electronic instability makes it extremely reactive: to stabilize itself, it will "steal" an electron from a neighboring molecule, which in turn becomes a free radical and seeks to steal another. It's a rapid and devastating chain reaction if not interrupted.
Not all free radicals are pathological. The body naturally produces them as part of normal cellular metabolism: mitochondrial respiration, immune response, certain enzymatic reactions. At low concentrations, some free radicals even play a useful role in cell signaling and defense against pathogens.
The problem arises when their production exceeds the body's neutralizing capacities. This is called oxidative stress: a state of imbalance between free radicals and antioxidants, in which cellular damage gradually accumulates.
A free radical is not an absolute enemy. It's an imbalance that becomes problematic when defenses can no longer keep up.
Where do excess free radicals come from?
The sources of excess free radicals are numerous and often cumulative. Ultraviolet radiation is the most documented source in the skin context: UVA and UVB trigger photochemical reactions in skin cells that produce massive amounts of free radicals, far beyond what natural defenses can neutralize.
Air pollution is the second major source. Fine particles, ozone, and polycyclic hydrocarbons penetrate the superficial layers of the skin and generate free radicals directly in the epidermis. Studies on urban populations show a clear correlation between chronic exposure to pollution and accelerated skin aging.
Tobacco, chronic stress, a diet rich in refined sugars and trans fats, excessive alcohol consumption: each of these factors increases the endogenous production of free radicals or reduces the body's antioxidant capacities. Often, both simultaneously.
What free radicals concretely do to the skin
The damage caused by free radicals to the skin acts on three main targets, each with distinct visible consequences.
The first target is collagen and elastin. Free radicals activate matrix metalloproteinases, enzymes that specifically degrade these structural proteins in the dermis. Chronic oxidative stress accelerates the depletion of the fibrous network, resulting in deeper wrinkles, loss of firmness, and less elastic skin.
The second target is the lipid membrane of cells. Free radicals trigger a process called lipid peroxidation: they oxidize the polyunsaturated fatty acids of cell membranes, making them rigid, permeable, and less functional. A degraded membrane no longer retains water effectively and communicates less well with its cellular environment.
The third target is DNA. Free radicals can directly modify the DNA bases of skin cells, altering the genetic instructions that govern their renewal and function. This DNA damage accumulates with age and contributes to the slowed cell renewal characteristic of mature skin.
The antioxidant network: how the body defends itself
Faced with free radicals, the body has an elaborate defensive arsenal that works at several levels. Enzymatic antioxidants, produced directly by cells, are the first line of defense: superoxide dismutase, catalase, and glutathione peroxidase neutralize free radicals at the intracellular level. Selenium is an essential cofactor for glutathione peroxidase: without it, this enzyme cannot function effectively.
Non-enzymatic antioxidants form the second line. Coenzyme Q10 is the reference fat-soluble antioxidant at the mitochondrial level: it neutralizes free radicals produced by the cellular respiratory chain and protects the internal membranes of mitochondria. Vitamin E is the fat-soluble antioxidant of external cell membranes: it protects membrane phospholipids against peroxidation. These two active ingredients work synergistically: vitamin E is regenerated by Coenzyme Q10 after neutralizing a free radical, allowing them to provide continuous protection.
Thymoquinone from nigella complements this network with a double action: it directly neutralizes free radicals and activates the body's endogenous antioxidant enzymes, amplifying both lines of defense simultaneously.
- Coenzyme Q10 Major mitochondrial antioxidant. Neutralizes free radicals at their source of cellular production. Regenerates vitamin E after neutralization. Natural production declines from age 30.
- Vitamin E Protects cellular lipid membranes against peroxidation. First line of defense for fatty structures against free radicals. Regenerated by CoQ10 for continuous protection.
- Selenium Cofactor of glutathione peroxidase, a first-line antioxidant enzyme. Without sufficient selenium, the entire enzymatic antioxidant network is compromised.
- Thymoquinone — Nigella Direct antioxidant action and activation of endogenous enzymatic defenses. Amplifies the effectiveness of the entire antioxidant network while acting on inflammation that aggravates oxidative stress.
- GLA — Borage Protects cell membranes in a complementary way to vitamin E by nourishing their lipid structure, making them less vulnerable to peroxidation.
Topical antioxidants or internal antioxidants: what's the difference?
Topical antioxidants, such as vitamin C or resveratrol in serum, act on the superficial layers of the epidermis. They neutralize free radicals produced on the surface by UV and pollution before they penetrate deeper. This is useful protection, particularly in the morning before exposure.
But the most serious oxidative damage occurs in the deep layers of the dermis, where free radicals attack fibroblasts, degrade collagen, and damage DNA. These layers are out of reach for topical antioxidants, whose molecules do not cross the epidermal barrier in sufficient quantities.
Antioxidants taken internally reach these deep layers via the bloodstream. They strengthen cellular defenses from within, regardless of the application of a topical product. The two approaches are complementary: topical protects the surface, internal protects the deeper layers.
Oxidative stress and inflammation: a vicious circle
Oxidative stress and chronic inflammation mutually sustain each other in a particularly destructive vicious circle for the skin. Free radicals trigger inflammatory reactions. These inflammations in turn generate new free radicals. Inflammatory mediators activate metalloproteinases that degrade collagen. And collagen degradation exacerbates vulnerability to oxidative damage.
Breaking this circle requires acting simultaneously on both fronts: neutralizing free radicals with powerful and bioavailable antioxidants, and reducing systemic inflammation with anti-inflammatory active ingredients like thymoquinone from nigella and GLA from borage. This is precisely the logic that guided the formulation of DE AUREA's Protocol N°79: a synergy of active ingredients that tackles free radicals and inflammation in the same daily gesture, with clinically relevant dosages and in their most bioavailable forms.
Free radicals do not accumulate suddenly. They accumulate every day, little by little. Antioxidant protection must also be daily.
Frequently asked questions about free radicals and the skin
Free radicals are unstable molecules that attack cell membranes, degrade collagen and elastin, and damage the DNA of skin cells. Accumulated over time, this damage results in premature skin aging, alteration of skin tone, wrinkles, and loss of firmness.
Free radicals are neutralized by antioxidants, endogenous (Coenzyme Q10, glutathione peroxidase) or supplied by supplementation (vitamin E, selenium, thymoquinone from nigella). These antioxidants give an electron to the free radical to stabilize it, interrupting the chain reaction before it damages cells.
Free radicals activate metalloproteinases that degrade collagen and elastin, alter the lipid membranes of skin cells, and damage DNA, slowing down cell renewal. The resulting chronic oxidative stress accelerates the appearance of wrinkles, loss of firmness, and dull complexion.
Yes. Antioxidants taken internally are distributed via the bloodstream to the deep layers of the dermis, where topical antioxidants cannot reach. Coenzyme Q10, vitamin E, selenium, and thymoquinone from nigella form a particularly well-documented complementary antioxidant network.
Oxidative stress is the imbalance between the production of free radicals and the body's antioxidant capacities. To reduce it: limit exposure to UV and pollution, adopt a diet rich in antioxidants, and support cellular defenses through targeted supplementation with bioavailable antioxidants such as Coenzyme Q10, vitamin E, and selenium.
