Vitamin C serums are one of those skincare products you hear about everywhere. Beauty editors rave about them, dermatologists recommend them, and your group chat probably has at least one friend who says it changed their skin completely. It’s meant to brighten, smooth, and give that healthy glow people chase for years.

Yet somehow, while others swear by it, your experience might be very different. You apply a few drops, and instead of radiance, your skin stings, turns red, or feels tight and uncomfortable. You’re left wondering whether you’re doing something wrong or whether your skin just can’t take it.

The truth is, irritation from vitamin C is common, but it’s also often avoidable. Understanding why it happens makes it much easier to choose a serum that works with your skin rather than against it.

What vitamin C actually does for your skin

Vitamin C, also known as ascorbic acid or its derivatives, is a powerful antioxidant. In skincare, it’s used to neutralise free radicals caused by UV exposure and pollution, support collagen production, and improve uneven skin tone¹.

When it works well, skin tends to look brighter, firmer, and more even over time. That’s why it’s so popular and why it’s often described as a “must-have” in many routines. But this same potency is also the reason some people experience irritation.

Why some vitamin C serums sting or burn

One of the biggest reasons vitamin C can feel uncomfortable is its acidity. Pure L-ascorbic acid, the most researched and effective form, needs a low pH to remain stable and penetrate the skin properly. This low pH can disrupt the skin barrier, especially if it’s already sensitive or compromised².

Concentration also plays a role. Many serums contain 15–20% L-ascorbic acid. While this works well for resilient skin, it can be too much for beginners or those with conditions like eczema or rosacea.

Then there’s formulation. Alcohol-heavy bases, poor stabilisation, or oxidation can all increase the likelihood of irritation. A serum that has turned yellow or brown is more likely to cause discomfort and is less effective overall.

This is often where people start asking, “Can vitamin C cause irritation?,” and the honest answer is yes, especially when the formula or usage doesn’t suit your skin.

Different types of vitamin C and how they affect sensitivity

Not all vitamin C is the same. Some forms are far gentler while still offering benefits. L-ascorbic acid is the most potent but also the most irritating. It works quickly but demands careful formulation and use.

Sodium ascorbyl phosphate and magnesium ascorbyl phosphate are gentler derivatives. They’re more stable, less acidic, and better tolerated by sensitive skin, although results may take longer to show.

Ascorbyl glucoside sits somewhere in between. It offers brightness and antioxidant support with a lower risk of stinging. If your skin reacts easily, switching forms can make a big difference without giving up vitamin C entirely.

How your skin barrier changes everything

Your skin barrier is the outer layer that keeps moisture in and irritants out. When it’s healthy, active ingredients are far less likely to cause problems. When it’s damaged, even gentle products can sting. Over-exfoliation, harsh cleansers, or using too many actives at once can weaken this barrier. Applying vitamin C to compromised skin often leads to burning sensations, redness, or breakouts.

This is why timing matters. Vitamin C may be perfectly fine for your skin on some days but irritating on others, depending on how your barrier is doing.

Common mistakes that make irritation worse

Many people don’t realise they’re unintentionally increasing irritation risk.

• Layering too many strong actives at once: Using vitamin C together with exfoliating acids or retinoids can overload the skin, especially if it’s sensitive or not used to actives.
• Applying more than needed: A few drops are enough. Using too much increases the chance of stinging without giving extra benefits.
• Applying to damp or freshly exfoliated skin: This allows vitamin C to penetrate more deeply, which often leads to burning, redness, or discomfort.
• Using it too often, too soon: Jumping straight into daily use doesn’t give your skin time to adjust. Starting slowly helps build tolerance and lowers irritation risk.
• Ignoring skin barrier health: When the skin barrier is already weakened, even well-formulated vitamin C can sting or flare sensitivity.

How to use vitamin C more gently

If you want the benefits without the burn, approach vitamin C slowly and thoughtfully. Start with a lower concentration or a gentler derivative. Use it two to three times a week before moving to daily application. Apply it to dry skin and follow with a soothing moisturiser.

Some people find buffering techniques helpful. One example people talk about is the benefits of the sandwich technique, where hydrating layers help reduce direct irritation from actives without completely blocking effectiveness.

Conclusion

Vitamin C isn’t meant to hurt, and any irritation usually comes down to formulation, concentration, skin barrier health, or how it’s being used. Once you understand these factors, it becomes much easier to make vitamin C work for you.

If you’re still struggling with sensitivity, persistent redness, or reactions that don’t improve, it may be time to get expert support. Angeline Yong Dermatology offers personalised consultations and advanced skin treatments to help address sensitivity, improve skin health, and achieve brighter, calmer skin safely. A professional approach can make all the difference when skincare feels confusing or frustrating.

References

Pullar, J. M., Carr, A. C., & Vissers, M. C. M. (2017). The Roles of Vitamin C in Skin Health. Nutrients, 9(8), 866. https://doi.org/10.3390/nu9080866

Telang P. S. (2013). Vitamin C in dermatology. Indian dermatology online journal, 4(2), 143–146. https://doi.org/10.4103/2229-5178.110593