Spotlight on… vitamin C

Known as a potent antioxidant that neutralises free radicals and promotes collagen synthesis, vitamin C is among the most frequently used skincare ingredients. Amanda Pauley outlines what makes it a skincare staple

Why the hype?

As one of 2021’s trendiest ingredients – it was the second most searched-for skincare ingredient on Google last year according to data from comparison site Skincare Hero – it’s no wonder clients are curious about vitamin C. “It is an essential ingredient for the health of our skin due to it high antioxidant power,” says Gina Baker, training manager at Germaine de Capuccini. “It increases the synthesis of collagen, which aids the repair of skin, making it essential in preventing scarring. Vitamin C also prevents transepidermal water loss, making it ideal to improve skin hydration.”

It can also help firm, brighten, correct damage and encourage healthy skin function. As the human body can’t synthesise vitamin C, clients need to obtain it from their diet, “We can only store it for a short period before the body eliminates it due to it being a watersoluble vitamin,” explains Victoria Evans, education manager at Dermalogica. “To get results in the skin, topical application is key, and daily application is needed.”

How does it work?

Vitamin C is a potent antioxidant that neutralises free radicals that are generated by our bodies when exposed to certain conditions, such as UV rays and pollution. “Free radicals can negatively impact DNA, lipids and proteins, causing a variety of diseases, damaging our cells and disrupting the skin’s ability to repair itself, slowing down collagen production,” says Evans. “This can result in lines, wrinkles, dullness and uneven skin tone.”

‘Typically, it’s best to apply vitamin C serums neat to ensure penetration into the skin – allow to absorb for a minute before applying moisturiser’

Applying vitamin C can help clients’ skin cope with this oxidative stress, giving potent antioxidant defence from environmental damage.

“Vitamin C regulates the synthesis of collagen by supporting the hydroxylation of collagen molecules, which is necessary for its extracellular stability and support of the epidermis,” she adds.

“It also increases the proliferation rate of fibroblasts – collagen-producing cells – acapacity that is decreased with age,”.

What are the different forms?

• Ascorbic acid – the most potent form. “It is very unstable, reacting to heat and light. It needs to work at a lower pH to be effective, which increases the chance of irritation,” says Baker.

• Magnesium ascorbyl phosphate – awater-soluble form ideal for brightening. “But it is not as effective as an antioxidant,” says Evans.

• Sodium ascorbyl phosphate – astable, water-soluble form. “It’s muchmore stable in formulations and proves to be kinder on the skin,” explains Baker.

• Ethyl ascorbic acid – soluble in both oil and water. “It works well as an antioxidant, however, its collagenboosting abilities are not as effective,” she adds.

• Ascorbyl glucoside – awater-soluble form. “Although not as potent, it still proves effective for increasing collagen production and inhibiting melanin formation,” says Baker.

• Ascorbyl palmitate – afat-soluble derivative that’s not as widely used because it lacks effectiveness for brightening and wrinkle reduction.

• Tetrahexyldecyl ascorbate – an oil-soluble form. “It penetrates the skin deeper and faster than other forms,” says Baker.

ACan vitamin C’s stability affect efficacy?

Delivery of topical vitamin C into the skin is dependent on how stable the formulation is and how susceptible it is to being oxidised.

“Traditional forms of vitamin C – for example, ascorbic acid – are easily oxidised upon exposure to air, heat or water, degrading the formula’s efficacy. This is evident when your product turns brown, or starts to smell funky,” explains Evans.

“These ‘pure’ forms are water-soluble and highly acidic, meaning they have the potential to cause skin irritation in higher percentages, which are often used to compensate for the high rate of instability within a formula.”

Encapsulated or ultra-stable forms ensure vitamin C is delivered to the skin where it’s needed. The instability can be overcome by stabilising vitamin C using various compounds, typically oil-soluble forms or by encapsulation technology, notes Evans.

“Newer technologies have advanced this stability for superior results, ensuring good shelf life and product effectiveness as the actives reach the target biological site before degrading.”

What are the dos and don’ts of using it?

Skin professionals recommend clients use vitamin C once per day. However, they should avoid using vitamin C with benzoyl peroxide, AHAs, BHAs or retinol.

“Not only do they cancel each other out, but they can cause skin irritation and redness,” explains Baker. “Instead, get clients to use vitamin C in the day and one of these other ingredients at night.”