Vitamin C Serum: The Ultimate Guide

You may see a new vitamin C serum on store shelves every week now, as well as other vitamin C products advertised in many new skincare products.

vitamin c serum ultimate guide

You’re probably also aware of the importance Vitamin C plays in your diet as a micronutrient.


Why is vitamin C an important ingredient to incorporate into your skincare routine?

How do you know when you might benefit from adding Vitamin C to your skincare regimen?

We tackle each topic and more in this ultimate guide to Vitamin C serums and your skin!

Why is Vitamin C important in skincare?

Signs such as fatigue, brain fog, hair loss, low immunity or digestive stress often accompany a lacking in vitamin C generally, but if your skin also shows any of the below signs, it may be time to incorporate vitamin C into your skincare regimen:

  • Inflammation
  • Acne
  • Dehydration; or
  • Loss of skin vibrancy

If you have these symptoms then your skin is showing signs of needing a bit of extra support. You can consider adding a Vitamin C serum to your daily skincare routine to make your skin look and feel healthier!

Also, if your skin tone generally is looking blah, you’re worried about sun spots or hyperpigmentation issues, or even if you’re just in the market for a solid serum, Vitamin C can be a welcome addition to your skincare routine.

What are the benefits of using Vitamin C serums?

Why Vitamin C?

vitamin c serum benefits

Well, Vitamin C is one of the most researched skincare ingredients. Below are just some of the specific benefits that have been proven through extensive research of this essential micronutrient.

When added into skincare routines, Vitamin C serums can:

  • help improve elasticity and reduce the appearance of fine lines and wrinkles;
  • combat dark spots and hyperpigmentation;
  • protect the skin from free radicals during the day and help skin recover from environmental exposure at night; and
  • boost collagen production and help soothe inflammation.

Plus, during the hot summer season, Vitamin C’s proven ability to help protect against sun damage and environmental stressors while hydrating your skin is especially timely.

Remember, Vitamin C is water-soluble which means certain levels of vitamin C are easily absorbed but beyond that, it can’t be stored in your body. You’ll end up peeing out any excess.  So, to replenish vitamin C regularly, eat foods rich in vitamin C, take supplements and also apply it to your skin as part of a consistent skincare routine.

The Different Types of Vitamin C

There are many types of Vitamin C, but if you’re going to use a skincare product with Vitamin C, be sure to look for two key ingredients:

  • L-ascorbic acid
  • 3-O-ethyl ascorbic acid

L-ascorbic acid in Vitamin C Serums

L-ascorbic acid is the most researched form of skin-related Vitamin C. It is the most effective type of the skin nutrient, and has been proven to help give the appearance of firmer, younger and more even looking skin. 

The problem? It's highly unstable and sensitive to air and light. This is where 3-O-ethyl ascorbic acid comes in.

3-O-ethyl ascorbic acid in Vitamin C Serums

3-O-ethyl ascorbic acid is considered a newer generation of Vitamin C derivative. It is one of the most stable forms of Vitamin C.

A Vitamin C serum that combines both L-ascorbic acid and 3-O-ethyl ascorbic acid becomes much more stable, so choosing a product that has both of these two key ingredients will help its potency last longer and prevent early oxidization.

Why SOFFLI's 16% Vitamin C serum specifically?

Based on detailed discussions with experts at our lab and from many reiterations of this product, we found that combining the two different forms of potent Vitamin C described above at a concentration of 16% is the sweet spot for your skin. This combination delivers a potent and stable dose of Vitamin C to your skin without irritation.

Vitamin C also works best in combination with vitamin E, ferulic acid and hyaluronic acid. I’m happy to report our serum contains all three!

Vitamin C and E are both power antioxidants and support each other. Ferulic acid is another antioxidant which boosts and stabilizes both vitamin C and vitamin E in fighting free radical damage and enhancing collagen production. Hyaluronic acid is a powerful humectant that binds up to 1,000x its own weight in water. We use a proprietary blend of short, medium and long-chain molecules; short-chains sink into deeper layers of the skin, medium-chains fill in the layers closer to the skin surface, and long-chain molecules lock in moisture on the top so that your skin is deeply-hydrated and plumped up at every level.

vitamin c serum 16% by soffli

Additionally, because Vitamin C can be highly unstable, it was crucial to get the packaging right.  We opted for an amber coated glass hands-free pump which includes at least 20% of recycled glass to protect from both air and light. We also recommend storing any Vitamin C serum in a cool, dry place away from direct sunlight. Storing in a cosmetics or wine fridge is even better.

The skincare product experience really comes down to texture and smell.  For texture, we wanted a serum that would feel lightweight and silky but at the same time feel nourishing and easily absorb into the skin. If you’re not careful, Vitamin C serums can end up feeling heavy and sticky and we made sure to avoid that.  

As for smell, our vitamin C serum is fragrance-free. 

Any subtle scents come naturally from the ingredients, and will likely fade soon after application. Staying away from fragrances in your skincare products can help you avoid skin irritation or allergic reactions.

How to apply Vitamin C serum for the best results

As always, with any new product, try a patch test prior to applying it to your face. 

If no irritation occurs within 24 hours, you can proceed with using it more broadly. If irritation occurs, you can also start by using it 2-3 times a week and work your way up to daily use. 

The sweet spot for your serum's vitamin C concentration is between 10 and 20 percent (sweet 16 for ours!).

Going over 20% has been shown to increase irritation but not much on the benefits side.  Remember everyone’s skin is different, so try experimenting to find a vitamin C concentration percentage that works best for you.

Again, since Vitamin C is a highly unstable ingredient, look for a product that comes in a dark or opaque glass bottle featuring an air-tight delivery system.  In addition, if you apply Vitamin C as part of your morning routine, sunscreen is a must.  Sunscreen will help prevent the Vitamin C from oxidizing on the skin, which thereby protects its efficacy.

How much do Vitamin C serums cost?

Our price for the SOFFLI 16% Vitamin C serum is one of the aspects we're most proud of and happy to share with you. 

how much do vitamin c serums cost

They’re really “pretty” and hopefully affordable for most of you because we cut out middle-men, glossy ads, glamorous models and more, and made them with the intent of sharing them with our friends, family and community.

Let’s be honest- no serum should cost $82, right?

Our belief is that you should be able to find a quality Vitamin C serum under $40 if you just do a bit of research – the SOFFLI serum is just $38!

Lastly, along with applying a quality Vitamin C serum to your skin every day, we recommend making sure you’re also consuming enough Vitamin C as part of your daily diet to keep your body and skin healthy! 

Fruits, such as kiwis, strawberries and oranges are high in Vitamin C and contain minerals and anti-inflammatory compounds which help encourage healthy aging and reduce the risk for chronic disease. Add this essential nutrient from the inside-out and the outside-in to boost your overall vibrancy and well-being.

Ready to start your new morning skincare regimen with a solid Vitamin C serum that will keep your skin hydrated and fresh all day long? Shop our 16% Vitamin C Serum here and contact our team if you have any questions or feedback!

By Minji