If you have your head in the skin care game, you’ve likely heard of vitamin C serums.

Vitamin C is touted as one of the best anti-aging ingredients on the market — and the key to maintaining a smooth, even, and glowy complexion.

Although you’re probably getting vitamin C in your diet, there’s no way to guarantee that it’s going straight to your skin. Using serums and other topical products is the most direct way to reap these benefits.

Read on to learn why you should add vitamin C serum to your routine, how to introduce a new product, and more.

Vitamin C has an excellent safety profile. Most people can use topical vitamin C for an extended period of time without experiencing any adverse reactions.

In rare cases, people who have hypersensitive skin may experience minor irritation.

Vitamin C is also safe to use in conjunction with other skin care actives, including alpha hydroxy acids, retinols, and SPF.

Magnesium ascorbyl phosphate, one of the main vitamin C derivatives used in skin care, has been shown to have a hydrating effect on skin. It decreases transepidermal water loss, allowing your skin to better retain moisture.

Vitamin C can help fade pigmentation (more on this below!) and smooth the skin’s surface to reduce dullness. This gives skin a youthful glow.

Vitamin C has also been shown to treat a huge variety of inflammatory skin conditions. Minimizing redness can create a more even complexion.

Hyperpigmentation — including sun spots, age spots, and melasma — occurs when melanin is overproduced in certain areas of the skin. It can also happen in areas where acne has healed.

Vitamin C application has been shown to impede melanin production. This can help fade dark spots and lead to a more even-toned complexion.

Dealing with acne? Vitamin C isn’t your only option. Learn more.

These serums can help smooth out fine lines by plumping and hydrating the under-eye area.

Although vitamin C is more effective at reducing overall redness, some people say that it can help alleviate discoloration associated with under-eye circles.

Want more? Here are 17 ways to get rid of under-eye bags.

Vitamin C is well known for boosting collagen production.

Collagen is a naturally occurring protein that depletes over time. Lower levels of collagen can lead to fine lines and wrinkles.

Check out five other ways to boost collagen production.

Collagen production is tied to skin elasticity and firmness. When your collagen levels begin to drop, your skin may begin to sag.

Applying a vitamin C serum may boost collagen production, resulting in an overall tightening effect.

Sun damage is caused by molecules called free radicals. These are atoms with a missing electron. Free radicals search for other atoms from which they can “steal” an electron —and this can lead to significant damage to the skin.

Vitamin C is rich in antioxidants. Antioxidants protect healthy skin cells by “giving” these free radicals an electron, rendering them harmless.

In addition to minimizing redness, vitamin C accelerates cell turnover. This replaces the damaged cells with healthy new ones.

Given its effects on sunburn, it should be no surprise that vitamin C application can speed up overall wound healing. Healthy wound healing reduces your risk for inflammation, infection, and scarring.

Although topical vitamin C is generally well-tolerated, all skin products have the potential to cause side effects. You should always do a patch test to assess your risk for allergic reaction. Here’s how:

  1. Select a small area of skin that’s easy to conceal, like your forearm.
  2. Apply a small amount of product and wait 24 hours.
  3. If no side effects occur, you can apply to your face. Discontinue use if you develop a rash, redness, or hives.

When it’s time for a full application, follow the instructions on the product’s label.

Vitamin C serum is typically applied once or twice per day. A good rule of thumb is to cleanse, tone, apply vitamin C serum, and then moisturize.

It can be safely used in conjunction with other active ingredients, although use alongside niacinamide may render vitamin C less effective.

Make sure to check your product’s use-by date. If the product has darkened or otherwise changed color, the vitamin C has likely oxidized. Although the product is still safe to use, it no longer carries the same benefits.

Although irritation is unlikely, you should always do a patch test prior to full application. This is the only way to determine how your skin will react to the serum.

If your skin is especially sensitive, avoid products with L-ascorbic acid. Products with magnesium ascorbyl phosphate may be less likely to cause irritation.

Serum stability is affected by two things — product formulation and packaging.

The following vitamin C derivatives are designed to retain potency for longer:

  • L-ascorbic acid
  • ascorbyl palmitate
  • magnesium ascorbyl phosphate

You should also ensure that the product has a water-free formulation. And the bottle should be opaque and airtight.

Popular vitamin C serums include:

Vitamin C can help heal blemishes, reduce hyperpigmentation, and give your skin an out-of-this-world glow.

Consistency is key for maximum effect, so add it to your routine in a way that makes sense for you. Some people apply it in the morning to take advantage of its UV-protectant properties, while others find that it works best as a night serum.

Discontinue use if you begin to experience irritation or discomfort.

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