Vitamin C is one of the most researched ingredients in skincare. It's been studied for decades, used in dermatology clinics long before it became a consumer trend, and the evidence behind it is genuinely robust.
It's also one of the most misunderstood. Not because it's complicated, but because the market is flooded with products that use different forms of it at wildly different concentrations, making it hard to know what you're actually getting.
Here's what the science says — and what it means for your skin.
What Vitamin C does
Vitamin C is a powerful antioxidant. Its primary function in skincare is neutralising free radicals — unstable molecules generated by UV exposure, pollution, and environmental stress that damage skin cells and accelerate visible ageing.
Vitamin C is one of the most researched ingredients in skincare. It's been studied for decades, used in dermatology clinics long before it became a consumer trend, and the evidence behind it is genuinely robust.
It's also one of the most misunderstood. Not because it's complicated, but because the market is flooded with products that use different forms of it at wildly different concentrations, making it hard to know what you're actually getting.
Here's what the science says — and what it means for your skin.
What Vitamin C does
Vitamin C is a powerful antioxidant. Its primary function in skincare is neutralising free radicals — unstable molecules generated by UV exposure, pollution, and environmental stress that damage skin cells and accelerate visible ageing.
Top benefits of Vitamin C
Left unchecked, free radical damage breaks down collagen, disrupts melanin production, and causes the kind of cumulative skin damage that shows up over years as uneven tone, loss of firmness, and dullness. Vitamin C interrupts this process before it starts.
But antioxidant protection is only part of the story. Vitamin C also directly stimulates collagen synthesis — it's an essential cofactor in the biological process that produces collagen, which means skin supplemented with Vitamin C produces more of it. Over time this improves firmness, reduces the appearance of fine lines, and supports the structural integrity of the skin.
It also inhibits melanin production. By blocking the enzyme responsible for converting amino acids into melanin pigment, Vitamin C gradually reduces the appearance of dark spots, post-acne marks, and sun damage — brightening the complexion and evening out skin tone with consistent use.
Why the form matters
Not all Vitamin C is equal and this is where most products fall short.
L-Ascorbic Acid is the pure, active form of Vitamin C. It's potent and fast-acting but notoriously unstable — it oxidises quickly on contact with air and light, turning products yellow or orange and losing efficacy in the process. It also requires a low pH to penetrate the skin effectively, which makes it more likely to cause irritation, particularly at higher concentrations.
Ascorbyl Glucoside is a stabilised derivative — Vitamin C bonded to glucose, which protects it from oxidation until it reaches the skin. Once absorbed, enzymes in the skin convert it to pure L-Ascorbic Acid where it becomes active. It's gentler, significantly more stable, and better tolerated across skin types including sensitive skin.
At F+A we use Ascorbyl Glucoside at 2% — a concentration with clinical evidence behind it, in a form that stays effective from the first use to the last.
What results to expect
Vitamin C works gradually and the timeline matters for managing expectations honestly.
In the first two to four weeks, most people notice a general improvement in radiance. Skin looks brighter and more awake — this is the antioxidant effect in action, with daily free radical damage being intercepted rather than accumulating.
Between six and eight weeks, uneven tone starts to improve. Dark spots and post-acne marks begin to fade. This happens because melanin inhibition is a slow process — the pigment that's already in the skin takes time to turn over naturally.
At three months and beyond, the collagen-stimulating effects become visible. Skin feels firmer. Fine lines appear softer. The overall quality and resilience of the skin improves in ways that go beyond what surface hydration can achieve.
This is why consistency matters so much with Vitamin C. The antioxidant protection is working from day one — but the most visible results take time to surface.
How to use it
Apply Vitamin C in the morning. As an antioxidant its job is daytime defence — neutralising free radical damage as it occurs throughout the day. Applied before SPF, it works alongside your sun protection to provide a more complete defence than either can achieve alone.
Apply it to clean, slightly damp skin before your moisturiser. A few drops is enough — you don't need a thick layer for it to work. Follow with moisturiser and SPF.
Vitamin C is compatible with most other actives in a routine. It layers well with Hyaluronic Acid, plays nicely with niacinamide at typical concentrations, and works synergistically with SPF. The main thing to avoid is using it alongside highly acidic exfoliants at the same time — not because they're harmful together but because the combination can cause irritation in sensitive skin.
Start daily from the beginning if you're using a stable derivative like Ascorbyl Glucoside — there's no adjustment period required. L-Ascorbic Acid at higher concentrations may need introducing gradually, but stabilised forms are gentle enough to use consistently from day one.
The bottom line
Vitamin C does three things that almost no other single ingredient does together — it protects against environmental damage, brightens and evens skin tone, and supports long-term collagen production.
Used consistently in the morning, it's one of the highest-return investments in any skincare routine. Not because it's fashionable, but because the evidence for what it does is decades old and the results, given time, are visible.
