Guide · Korean skincare
Vitamin C Ampoule vs Serum: What's the Difference?
If you shop Korean skincare you'll see vitamin C sold as both "serums" and "ampoules." Here is what the words actually mean, what to look for on the label, and how to use either one.
What is an ampoule?
"Ampoule" is a Korean-skincare term for a concentrated serum. It is not a regulated category: it signals a product built around a higher dose of one hero ingredient for a specific concern, such as dullness. A serum is the broader name for a light, water-based treatment step.
In practice you use both the same way: after cleansing (and toner or a sheet mask), before moisturizer and, in the morning, sunscreen.
What the vitamin C percentage tells you
Look for the form of vitamin C and its percentage. Ascorbic acid is the pure form of vitamin C and the most studied in skincare. Higher percentages are more intense, so they suit people who want a focused brightening step; beginners or sensitive skin often start slowly.
Because pure ascorbic acid breaks down with water and air, the formula and packaging matter as much as the number. A stabilized formula and a pump bottle help keep the vitamin C fresh.
An example: the UNI&CORE Vita C 13.5 ampoule
The UNI&CORE Vita C 13.5 Super Brightening Ampoule contains 13.5% pure vitamin C (ascorbic acid), stabilized in a dual-layer formula with a high hydration level, plus glutathione, camu camu, hyaluronic acid and panthenol. It comes in a 1.06 oz (30 g) pump bottle; the brand recommends 2 pumps after cleansing.
In a 7-day human application test with 21 adults aged 20–60 (SKINMED Co., Ltd. Clinical Trial Centre), skin glow improved by 35.6% and elasticity by 14.3%. Individual results may vary.
13.5% Pure Vitamin C (Ascorbic Acid)
UNI&CORE Vita C 13.5 Super Brightening Ampoule
1.06 oz (30 g)
Can you use an ampoule and a serum together?
Yes. Apply the thinnest, most concentrated product first and layer the rest from thin to thick. If you are introducing a new vitamin C product, start with it once a day and see how your skin responds before adding more steps.
FAQ
Is an ampoule stronger than a serum?
Usually an ampoule is positioned as the more concentrated, targeted step, but the label is what counts: compare the ingredient, its form (for vitamin C, ascorbic acid) and its percentage.
Do I need both an ampoule and a serum?
No. One well-formulated vitamin C step is enough for most routines. Add other serums only if they target a different need, such as hydration.
When should I apply a vitamin C ampoule?
After cleansing and toner (or a sheet mask), before moisturizer. In the morning, finish with sunscreen.
Where can I buy the UNI&CORE vitamin C ampoule?
On Amazon.com through the official UNI&CORE listing. Use the Shop on Amazon button in this guide.
Test results are from UNI&CORE's human application tests and may vary by individual. These products are cosmetics and are not intended to diagnose, treat, cure or prevent any disease.