Our most advanced pure vitamin C serum for instant and visible brightening.

This clinically proven serum is powered by 15% L-ascorbic acid, the purest and most active form of vitamin C, to instantly brighten skin while visibly improving uneven tone, texture, fine lines, wrinkles, and loss of firmness.

L-ascorbic acid is intentionally combined with ferulic acid and vitamin E to create a highly potent, non-irritating serum that remains gentle enough for twice daily use. Along with boosting vitamin C’s stability, these additional antioxidants also increase skin’s protection against the environmental stressors that trigger dark spots, discoloration, and premature skin aging.

Suitable even for sensitive skin, this brightening serum boosts skin’s hydration while absorbing quickly, without an oily or greasy residue. When used consistently, it leaves skin looking smoother, more even, and noticeably more radiant.

At a glance:
- Helps skin look instantly brighter with L-ascorbic acid (pure vitamin C)
- Clinically proven to improve visible signs of aging*
- Clinically proven to boost hydration**
- Ferulic acid & vitamin E boosts skin’s defenses while stabilizing vitamin C
- Lightweight, fast-absorbing serum layers well under makeup
- Non-irritating formula is suitable for all skin types***
- Has an optimal pH range of 3.10-3.50
*Based on an independent clinical study with 30 subjects after 4 weeks, using expert grading.
**Based on an independent clinical study with 31 subjects after 1 week, using instrumental measurement.
***Shown to be non-irritating under normal conditions of use.

Behind the science:
L-ascorbic acid (also known as pure vitamin C) is vitamin C in its active form, ready to work as soon as it’s absorbed by skin. Because it doesn’t require conversion, it’s considered the most efficient form of vitamin C. The tradeoff? L-ascorbic acid can be unstable and may cause irritation in some formulas. That’s why it’s paired with ferulic acid and vitamin E, which help stabilize the vitamin C.

C15 Super Booster’s improved formula delivers high-potency vitamin C with minimised irritation. New technology targets dullness & uneven tone for a firmer, more radiant complexion with the addition of ergothioneine to boost efficacy for advanced results. Ferulic acid defends against discolouration and boosts 15% vitamin C’s stability. Diminishes visible signs of ageing for brighter, smoother skin with an exclusive blend of 15% stabilised vitamin C (l-ascorbic acid) at a pH range of 3.1–3.5, potent antioxidants ferulic acid, ergothioneine, vitamin E and skin-smoothing peptides. You’ll see younger-looking and more radiant skin with each use.

When To Apply
Apply up to twice daily, in the AM and PM, after cleansing and toning/exfoliating. For daytime, always finish with sunscreen. For nighttime, follow with the rest of your routine.

How To Apply
Smooth 2-3 drops over your face and neck. Can be used alone as a serum or added to your moisturizer.

Key Ingredients
Ascorbic Acid, Ferulic Acid, Tocopherol

Product Ingredients
Aqua/Water/Eau, Ascorbic Acid, Dipropylene Glycol, Propanediol, Glycerin, Ethoxydiglycol, Sodium Hydroxide, PPG-26-Buteth-26, PEG-40 Hydrogenated Castor Oil, Bisabolol, Ferulic Acid, Sodium Phytate, Decylene Glycol, Tocopherol, 1, 2-Hexanediol, Sphingomonas Ferment Extract, Phenoxyethanol

1. What makes the latest version of the C15 Super Booster different?

The new C15 Super Booster features the same 15% pure vitamin C in a formula designed for improved stability and a more consistent experience from first use to last drop. We streamlined the formula to focus on the ingredients that matter most, helping minimize oxidation and improve how the product feels on skin—lightweight, fast-absorbing, and easy to layer. The result is a vitamin C booster that helps improve radiance and remains suitable for everyday use.

2. What does vitamin C do for skin?

This vitamin C booster helps brighten dull skin, improve the look of uneven tone, and support firmer-looking skin over time. Its antioxidant benefits also help defend against environmental stressors, leaving skin looking more radiant and refreshed.

3. Who is the formula ideal for?

C15 Super Booster is suitable for all skin types seeking a daily dose of glow, antioxidant defense, and for targeting concerns such as minor discoloration, dullness, and fine lines.

4. How long does it take to see results with the C15 Super Booster?

Skin looks instantly brighter from the first application. Within one week, hydration is visibly improved, and after four weeks, skin feels smoother, tone appears more even, and dullness is noticeably reduced—while fine lines look softened. With continued twice-daily use, skin becomes visibly brighter and more radiant over time.

5. Does the formula contain fragrance, dyes, parabens or silicones? Is it vegan?

No, C15 does not contain fragrance, dyes, silicones (or siloxanes), or parabens. Yes, it is vegan.

6. What is the difference between the C15 Super Booster and the 25% Vitamin C + Glutathione Clinical Serum?

C15 Super Booster contains 15% pure vitamin C (ascorbic acid) and is a good option for daily use to help improve the look of dullness and uneven tone. It can be used on its own or mixed into a serum or non-SPF moisturizer.

25% Vitamin C + Glutathione Clinical Serum uses vitamin C derivatives and is better suited for more advanced concerns like uneven tone, discoloration, and loss of firmness. You can use either product on its own or both in the same routine, depending on your skin concerns and tolerance. If using both, start slowly and adjust as needed.

7. What antioxidants are in the C15 Super Booster?

The C15 Super Booster pairs 15% stabilized vitamin C, a superstar antioxidant that visibly evens skin tone and defends against free radicals with two powerhouse partners: ferulic acid, which stabilizes vitamin C and helps defend against discoloration, and vitamin E, one of the most well-researched antioxidants in skincare, known to protect skin and boost overall formula efficacy. Together, this trio works to visibly brighten skin and even your complexion.

8. Can I use the C15 Super Booster with sunscreen?

Yes, and we recommend it. Vitamin C and sunscreen complement each other for daytime use. Apply the C15 Super Booster after cleansing, then finish your morning routine with a moisturizer rated SPF 30 or greater. If you prefer to mix the booster into a moisturizer, choose a non-SPF moisturizer so you do not dilute your sun protection.

9. Can you combine vitamin C and retinol?

Yes. To get the best results, we recommend using vitamin C in the morning (to brighten and even skin tone) and retinol at night (to smooth skin and target signs of aging). Introduce them gradually to ensure your skin tolerates the combination well.

10. Can you combine vitamin C and niacinamide?

Yes. These two ingredients work well together and can be used in the same routine. Vitamin C boosts radiance and fades discoloration, while niacinamide calms the skin and visibly minimizes pore size. This combination is generally well-tolerated, but it’s always best to start slowly if you have sensitive skin.

11. Can I use this booster while pregnant or breastfeeding?

This vitamin C formula does not contain ingredients typically restricted during pregnancy. However, if you have questions about starting a new product while pregnant or breastfeeding, speak with your healthcare provider.

12. What color should the C15 Super Booster be?

C15 Super Booster can range from clear to pale peach or amber. That color variation is normal, and vitamin C may darken over time.

For best results, store your C15 Super Booster in a cool, dark place away from direct sunlight and excess heat. Keep the cap tightly closed when not in use. Once opened, using it within 3 months helps ensure optimal freshness and performance. Tip: Use a Sharpie-like marker to write the date you opened it on the bottom of the bottle to help keep track.

13. What’s the difference between a booster and a serum?

A booster is more concentrated and designed to target a specific concern. A serum usually contains a blend of ingredients for broader benefits. C15 Super Booster delivers 15% pure vitamin C and can be used on its own or mixed into a serum or non-SPF moisturizer. Our 25% vitamin C serum combines vitamin C derivatives with other supportive ingredients for more comprehensive care.

14. Can I mix the C15 Super Booster with other products, and is there anything to avoid?
Yes. The C15 Super Booster is designed to work well with most skincare products without reducing its effectiveness. The only ingredient to keep separate is copper peptides, as they can make pure vitamin C less effective. If you use both, apply one in the morning and the other at night. Otherwise, vitamin C pairs well with a wide range of ingredients, including antioxidants, niacinamide, AHA, BHA, and PHA. You can use it on its own or mix a few drops into your favorite serum or non-SPF moisturizer for added convenience.