Vitamin C is the most-searched skincare ingredient in Australia — by a distance. A study of Google search data put it at roughly 327,000 searches a month here, and top of the list in more than sixty other countries too.
It is also one of the most oversold ingredients on the shelf. So here is the honest version.
What it's actually for
Vitamin C is an antioxidant. In skincare it's used for the appearance of brightness and a more even-looking tone. If your skin looks dull, or pigmentation makes the tone uneven, it's a sensible thing to reach for.
What it is not is a treatment. It doesn't cure anything, and a brand that tells you otherwise is either careless or counting on you not checking. We'd rather be the brand that says so.
The mistake almost everyone makes
Vitamin C oxidises. Light and air degrade it, and as it degrades it stops doing much of anything. You can watch it happen: a fresh serum is pale straw, and as it oxidises it turns amber, then brown.
If your serum has gone orange, it isn't "mature" or "concentrated". It's spent — and we've written a fuller guide on what the colour change means and whether to bin the bottle.
Which means the two things that matter most are boring ones. Keep the lid on, and keep the bottle out of the light. A bathroom windowsill in Queensland is close to the worst place in the house for it. A drawer is close to the best.
On concentrations
You'll see percentages quoted like a spec sheet — 10%, 15%, 20%. Higher isn't automatically better. Above a certain point you get diminishing returns and a greater chance of irritation, particularly on skin that isn't used to it. If you're starting out, starting lower and staying consistent beats starting high and giving up in a fortnight.
When to use it
Morning or evening both work. What matters more is that it goes onto clean skin and gets a moment to absorb before anything else goes on top — the order you apply things matters less than most charts suggest, but this bit genuinely does.
In the morning it sits under sunscreen, never over it. If you use light therapy, apply the serum first and let it settle before the light.
The thing nobody selling you serum wants to say
No serum outperforms sun protection. If you're going to be diligent about exactly one thing in your routine, it isn't this one — it's what you do about UV exposure, which in Australia is not a small consideration.
Vitamin C is a good addition to a routine. It is not the routine. Anyone implying otherwise is selling.
Related reading
- Why your vitamin C serum turned orange — and whether to bin it
- Vitamin C and sunscreen: which one goes on first?
- Can you use niacinamide and vitamin C together?
- Retinol or vitamin C: do you actually need both?
Ours is the Radiance Vitamin C Serum, made in Australia.
This article is general information, not personal advice. If you have a skin condition or take prescribed medication, talk to your GP or dermatologist.
