When should you use vitamin C serum—morning or night?

A comprehensive guide on when you should apply your vitamin C serum, morning or night, and what the benefits of each really are

image showing a bottle of serum next to a pipette and drops of serum, on an orange and yellow background—to signify an article on when to apply vitamin c serum, morning or night?
(Image credit: Future/Getty)

When is the best time to apply your vitamin C serum, morning or night? It's likely a question that most vitamin C users have turned over in their head at one point or another—as we all know that vitamin C isn't the most easygoing of ingredients. So while we can ensure that it's at its most efficacious by keeping it out of direct sunlight and preventing exposure to other elements, seeing the very best results on our skin could be all down to our timing.

There is no doubt that adding one of the best vitamin C serums to your routine is one of the many keys to unlocking great skin. It works to protect skin against free radicals and other damaging environmental factors like pollution and UV, while helping to encourage skin cells to produce collagen—which is naturally occurring in the skin but decreases as we get older. It is also famed for inhibiting the production of melanin so helps to fade discoloration and dark spots.

What’s even more impressive is that it’s one of the few scientifically proven ingredients that can actually help improve existing, visible signs of aging.

This means that regular use of a vitamin C serum will leave skin even-toned, radiant, plump and free of any fine lines or wrinkles—as long as you've nailed how to use a vitamin C serum properly.

There is an ongoing debate around whether vitamin C is best used as part of your daily morning routine or whether it should be applied before bed so it can work its magic through the night. 

We’ve broken down the benefits of both ways to help you make an informed decision based on what’s right for your skin type, so that you soak up all the endless benefits of vitamin C to the very best degree.

Vitamin C serum morning or night

(Image credit: Getty / Moment)

How to use vitamin C in the day and its benefits

Vitamin C is one of the most powerful antioxidants out there. That means it really comes into its own during the day when it can get to work protecting skin against harmful elements like pollution, free radicals, UV rays, and other factors that can leave skin looking dull and lifeless. 

If you are using your vitamin C serum during the day, it should always be followed by one of the best sunscreens for face—preferably with SPF50, but at least a minimum of SPF30—to help protect skin against the sun. However, if your skin is super sensitive and prone to irritation, you may want to switch it up. You could either use a gentle antioxidant during the day and switch to using vitamin C at nighttime instead. Or, you could opt for a lower strength vitamin C serum which is less likely to cause any sensitivity or reaction. 

How to use vitamin C at night time and its benefits

While you’re sleeping, your skin undergoes its natural repair process. During sleep skin’s blood flow increases, it rebuilds collagen and repairs damage like fine lines, wrinkles and age spots that have been caused by UV exposure. So using vitamin C serum during the night means that it's likely to have the most effective impact on the skin. 

If your chosen serum is quite potent, like the Medik8 Super C30 Intense, you also reduce the risk of photosensitivity occurring (a reaction that can be triggered by sunlight) if you use it during the nighttime.

It’s worth adding that if you do choose to use vitamin C at night, you should always ensure you’re using SPF the following day to ensure maximum efficacy.

The benefits of using vitamin C in the morning and in the evening

Think of slathering vitamin C in the morning and night as the best of both worlds. You get to reap the rewards of vitamin C's powerful antioxidant properties by essentially getting a double dose. 

One thing that you need to consider is that the skin has a limit for absorbing vitamin C. In other words, once this limit has been reached, any extra product is essentially wasted (and it doesn't come cheap). So if you’re using a product that’s more gentle and has a lower percentage of vitamin C in it—like the La Roche-Posay Pure Vitamin C10 Serum—you’re good to use it twice a day. But if your chosen serum has a higher, more potent level in it then it’s best to adopt a less is more approach and stick to using it just once.

So, should you use vitamin C in the morning or night?

While it’s all down to your skin (and no one knows your skin better than you), most prefer to apply vitamin C serums in the morning because of its antioxidant properties—which means that it helps to defend against pollutants and free radicals that could otherwise damage skin throughout the day. However, never forget to follow with SPF to protect your skin against the sun.

If your skin tends to verge on the sensitive side, then using vitamin C at nighttime is advisable. And if you want to really make the most out of your product, nighttime use of vitamin C would be preferable too, as it will have the biggest impact on your skin thanks to the skin repair process that occurs during sleep.

Lucy Partington
Lucy Partington

Lucy Partington has been a beauty journalist for eight years, writing for titles including Stylist and Cosmopolitan. She’s a true skincare nerd who’s on a lifelong quest for a glowing complexion and loves nothing more than learning about new ingredients and products. She’s obsessed with having perfect eyebrows and collecting eyeshadow palettes she’ll probably never use.