Ascorbic Acid, vitamin C

Vitamin C is one of the best pigment correctors for pigmentation disorders such as melasma, post inflammatory hyperpigmentation as well as age spots & photoaging. It is best combined with other ingredients such as tocopherol & ferulic acid to provide antioxidant effects, with additional effects such as skin brightening & skin lightening. Learn more about the benefits of vitamin C & how to use it.


Anti-pigmentation, anti-aging, antioxidant

When to use

AM or PM

Works with

Azelaic acid, niacinamide

Caution with

Retinol, Hydroquinone

Dermatologist science score

What is vitamin C or ascorbic acid?

Vitamin C or ascorbic acid forms the basis of skin care, namely the third vitamin in the ABCs of dermatology (Vitamin A is retinol, vitamin B is niacinamide). This vitamin plays an important role in skin health.

What can ascorbic acid do for my skin?

Vitamin C has 3 main roles in the skin-

  • As a collagen builder, it acts to increase the building blocks of skin, increasing collagen & elastin production- hence its role in anti-aging. This reduces wrinkles, lines & skin laxity.
  • As a potent pigment inhibitor, it reduces pigmentation in the skin, hence its use in the treatment of melasma, post inflammatory hyperpigmentation & sun-age spots.
  • Antioxidant; vitamin C protects the skin from free radicals due to sun exposure & environmental pollution. It acts synergistically with vitamin E or tocopherol. Oxidation plays a key role in synthesis of melanin pigment.

Why use vitamin C to treat hyperpigmentation & melasma?

Hyperpigmentation including melasma, sunspots & post inflammatory hyperpigmentation from acne occurs when melanin is overproduced in certain areas of the skin.

Vitamin C application has been shown to reduce melanin production by inhibition of the enzyme that produces pigment, tyrosinase. This enzyme is found in cells responsible for pigment, namely the melanocyte.

How long does vitamin C take to lighten melasma pigmentation?

You should notice a difference within 3 to 6 weeks, depending on the type & depth of pigmentation. Maximal effects can be seen in 12 weeks. As with all depigmenting agents, vitamin C works best for superficial forms of pigmentation, including epidermal or mixed melasma. It does not work well for deep dermal melasma.

Does vitamin C work on all forms of skin pigmentation?

Ascorbic acid (vitamin C) only works for superficial melasma & pigmentation, whilst mixed & dermal melasma/pigment do not respond well to skin care.

Here is a guide-

Pigment type

Pigment depth


Superficial pigment (works well) Superficial melasma Works well
Light melasma Mixed melasma, post inflammatory hyperpigmentation Moderate efficacy
Deep pigment Dermal melasma Doesn't work

For deeper forms of pigmentation such as deeper melasma, post inflammatory acne marks, & Hori, picosecond lasers work better.

What is better- vitamin C or hydroquinone creams?

HQ or hydroquinone works a lot better than vitamin C, however the former has more side effects & can only be used for a finite time frame. In summary-

Pigment corrector

Maximal use

Side effects

Pigment reduction Capacity

Vitamin C Infinite Skin irritation Low to moderate
Hydroquinone 3-5 months Skin irritation, ochronosis, tachyphylaxis; stops working. Moderate to high

Vitamin C is hence used as part of a rotational therapy in the treatment of melasma, or as part of HQ formulation (see below).

Why then is vitamin C formulated with hydroquinone?

HQ or compounded hydroquinone is inherently unstable, meaning it will go off with time, heat & sun exposure. Ascorbic acid is often added to the formulation to stabilize hydroquinone to increase the shelf life. It acts as an antioxidant. In this context the concentration varies from 1 to 3%, as compared to 10- 20% L ascorbic acid serum.

What are other formulations & ingredients that are combined with vitamin C?

Given the banal nature of vitamin C & its lower activity on the enzyme that produces pigment, it is often combined with agents such as arbutin, azelaic acid, kojic acid, licorice root extracts, green tea & bearberry extracts. If combined with the above agents, the concentration of vitamin C varies between 3 to 10%.

When do we introduce vitamin C into your melasma program?

We introduce vitamin C in to your program in 3 steps-

  • If your melasma is superficial & mild.
  • As part of rotational therapy (be guided by your clinician as to the timing, concentration & formulation of vitamin C).
  • In pregnant & breastfeeding women as other products such as retinol & hydroquinone are not compatible during this time.

Can I use Vitamin C serum everyday?

Vitamin C serum is typically applied once a day. Cleanse, apply vitamin C serum, then follow up with a SPF 50+ sunscreen.

Applied in the morning vitamin C acts as an antioxidant, protecting your skin against UV rays. It can be combined with ferulic acid & tocopherol.

Applied in the evening, ascorbic acid works by decreasing pigment production & aids in improving skin tone by building new collagen. The ideal time will be determined by your clinician as we often combine vitamin C with other agents.

How should I commence ascorbic acid?

High bioavailability L-ascorbic acid formulations are in the pH region of 2.5 to 3.0. This acidity enhances the potency of vitamin C at the expense of skin irritation as this is more acidic than the skin’s normal pH.

Start at a low to medium concentration of L-ascorbic acid, namely 5 to 10%. Increasing as tolerated. For sensitive skin types, start with alternate day application, titrating up as tolerated. As vitamin C levels accumulate in the upper layers of skin, the potency of some formulations last up to 72 hours. Be guided by your treating clinician.

Why should you be cautious of vitamin C if you have sensitive skin?

Ascorbic acid is an acid with an optimal pH of around 2.5. This can frequently irritate & inflame conditions such as rosacea, seborrheic dermatitis & eczema. Though not an absolute contraindication, the initiation of vitamin C in these patient groups must be cautiously titrated. Formulations, concentration, timing, & adjuvant therapies are taken into consideration.

Pigment inhibitors such as azelaic acid, niacinamide, green tea, & botanicals are less irritating on the skin as compared to vitamin C & hydroquinone.

Can I use retinol & vitamin C together?

It’s best to apply vitamin C before retinol, as vitamin C has a lower pH than retinol. Ideally vitamin C is used in the am, whilst vitamin A (retinol) is used in the evening.

Using both together will alter the skin’s pH, rendering actives less potent than if individually spaced apart. Combination therapy can also irritate the skin.

What should I not mix with vitamin C serum?

Vitamin C is an acid with a low pH, so layering it with lactic, glycolic & mandelic acids will land you in trouble. Higher strength vitamin C should not be mixed with prescribed hydroquinone (exceptions apply, read further).

Here is a quick checklist to see what should not be mixed together-


How to use vitamin C & hydroquinone?

Be guided by your clinician as this can be difficult for beginners, especially if you are sensitive to HQ. We prefer to use vitamin C in combination with antioxidants in the AM, as tolerated, whilst HQ is used in the evening.

A simple guide is- L-ascorbic acid 15%, tocopherol & ferulic acid then SPF 50+, hydroquinone post cleansing in the PM. Pulsed therapy is sometime used to taper off HQ towards the end of your depigmentation regime.

When to recommence vitamin C after laser treatment of melasma?

Your clinician will guide you as to how to recommence vitamin C after the laser procedure. We generally recommend that you avoid serums for 12 to 36 hours post laser, however we may use lasers to enhance the penetration of some topicals including ascorbic acid.

When to recommence vitamin C after melasma peels?

Your treating therapist will guide you as to how to recommence vitamin C after peeling. We recommend that you avoid serums for 5 to 18 days after peeling as your skin barrier function is compromised.

As a guide-

  • Glycolic or lactic acid peels: wait 5 to 6 days
  • Retinoic acid peels: wait 7 to 9 days
  • Vi Precision peels: wait 9 to 10 days
  • Cosmelan or Dermamelan peels: use Cosmelan 2, included in the peel pack

What Vitamin C serum is the most effective?

Formulations matter & picking the optimal serum for your skin type is not as easy as recommending one product. In most cases, cheap & nasty products such as The Ordinary do not have the best formulations. Look past the concentration as often the rate limiting factor is skin irritation. Here are our favorites- Rationale, Obagi, Synergie, Medik8 & Skinceuticals.

Your clinician will provide you with recommendations based on your skin sensitivity, concomitant use of other topical products & depth of pigmentation. We also take into consideration the phase of depigmentation you are in.

How do we rate vitamin C powder from The Ordinary?

The Ordinary has two main formulations; Vitamin C Suspension 23% + HA Spheres 2% & The Ordinary Magnesium Ascorbyl Phosphate 10% has a lower concentration, & maybe less irritating, however it is generally less biologically active compared to say, L-Ascorbic Acid.

The Ordinary makes some good formulations, especially cleansers such as squalene (wash off products). However home mixed ascorbic acid has both pluses & drawbacks. Making a fresh batch of L-Ascorbic Acid guarantees the potency as this molecule is heat & light labile. The flipside is that concentrations are not as accurate as lab compounded formulations. Too high a concentration will cause significant irritation -especially at higher concentrations exceeding 15%.

Bottom line, we do not endorse this product by The Ordinary, however as mentioned they do produce other skin care products that are awesome (mandelic acid, squalene are examples).

Can vitamin C treat wrinkles & should I use it?

This vitamin can be a powerful anti-aging ingredient, as it prevents collagen breakdown whilst at the same time promoting new collagen formation. It also reduces the breakdown of collagen via its antioxidant properties.

In the context of melasma & pigmentation, it can be a useful adjunct IF you can tolerate it. For pigmentation reduction, we prefer stronger formulations but employ vitamin C as part of your rotational therapy. Be guided by your skincare expert as to when & how to introduce this vitamin into your melasma routine.

As an anti-aging formulation, the use of vitamin C is for mitigation, remembering that mitigation effects are results you don’t see (hence the true definition of anti-aging, ie. prevention). For reversal of established wrinkles, lasers & injectables such as Rejuran are much more effective as compared to skin care formulations. This includes vitamin C.

Who should not use vitamin C?

Ascorbic acid, as the name suggest, is an acid. It has a lower pH compared to your skin. Good formulations of vitamin C are usually less than pH 3.2, whilst your skin’s natural pH hovers around 4.7. This makes vitamin C as one of the more irritating pigment inhibitors out there.

Be cautious if you suffer from –

  • Rosacea, flushing, blushing
  • Eczema, dermatitis
  • Sensitised skin (using too many products, poor formulations, or wrong combinations)

What can I use if I can not tolerate ascorbic acid?

You are better off swapping ingredients rather than persisting with vitamin C if your skin does not tolerate this powerful ingredient, however, before giving up run through this check list-

  1. Are you using the correct formulation? L ascorbic acid is best. Stick to good brands such as Synergie, Skinceuticals, & Zo.
  2. Is your concentration too high?
  3. Are you mixing other ingredients such as exfoliants, scrubs, retinol, retinoids, hydroquinone, glycolic acid, & kojic acid?
  4. Is your skin’s barrier function compromised?
  5. Have you taken steps to optimise your skin’s hydration & barrier?

If you still can not tolerate vitamin C, consider substituting it with-

  • Azelaic acid: well tolerated by most, this acid has a higher pH than ascorbic acid & has anti-inflammatory properties.
  • Niacinamide: or vitamin B3 is well tolerated. It has mild to modest pigment inhibition & repairs the skin barrier.
  • Botanicals – liquorice root, bearberry extract, found in Meladerm formulations.

How do I incorporate ascorbic acid in my daily routine?

AM: Gentle cleanser, then L-ascorbic acid, SPF 50+, makeup with iron oxide (HEV protection)

PM: Cleanser, pigment corrector of choice (HQ, arbutin, kojic acid, botanicals, azelaic acid).

A SummaryDavin’s viewpoint on vitamin C for melasma & pigmentation

Dr Davin Lim | Dermatologist
The Melasma Clinic, Brisbane | Sydney

A tick from us, providing you can tolerate this ingredient. It is much harder to use as compared to more banal, less irritating ingredients such as niacinamide or azelaic acid. Stick with well known brands with good formulations- you get what you pay for.

My favourite formation (from a science point of view) is Skinceuticals CE Ferulic acid as it takes care of the morning routine as it combines 15% L-ascorbic acid (great percentage) 1% vitamin E & 0.5% ferulic acid. This functions as both an antioxidant & a pigment suppressor with activity up to 72 hours post application. Antioxidants are useful against HEV, visible light, as well as a tiny bit or IR or infrared attenuation.

Hence for this product your pigment routine is simplified to look like this-

CE Ferulic acid 30 minutes before tinted sunscreen, then mineral make up. Done.

Two downsides- the cost at nearly $250 AUD & the smell. Overlook these factors & it is a winner.

*Costing is not so much an issue. If you look at 4-5 applications per week, a bottle of serum will last 6 to 8 months. Cost is equivalent to $1.50 cent daily.


INGREDIENT list of CE Ferulic Acid

  • 15% L-ascorbic acid: L-ascorbic acid is a highly potent form of pure vitamin C that neutralise free radicals and protect against oxidative stress, from UV sources & environmental pollution. It can provide visible anti-ageing benefits, in combination with lasers.
  • 1% alpha tocopherol: vitamin E neutralises free radicals and replenishes skin lipids.  It has been proven to act synergistically with vitamin C to renew this vitamin & assists in the antioxidant role. Vitamin E is also important for skin barrier function & is anti-inflammatory.
  • 0.5% ferulic acid: A plant-based antioxidant, ferulic acid neutralises free radicals, reduces oxidative stress. It also optimises the antioxidant benefits and stability of vitamins C and tocopherol.



What is the science behind SkinCeuticals?

Research shows that specific combinations of antioxidants perform synergistically to provide results superior to each single antioxidant formulation.

Published in peer-reviewed scientific journals, C E Ferulic is a vitamin C serum formulated under the Duke Antioxidant patent. Vitamin C is a potent antioxidant that is, by its structure, difficult to effectively deliver on skin.

The Duke Antioxidant patent describes the formulation parameters required for effective delivery of vitamin C to skin:
1) pure l-ascorbic acid (vitamin C);
2) an acidic pH within the 2.0-3.5 pH range and;
3) a concentration between 10%-20%.

Triple Antioxidant Protection For Up To 48% Less Damage From Free Radicals^
^Cosmeto-clinical study, 15 subjects, after 4 days of use vs. untreated skin

Improves signs of ageing*
Reduces the appearance of wrinkles by up to 36%
Reduces the appearance of discolouration by 39%
Enhances skin radiance by up to 44.8%

*Cosmeto-clinical study, 52 subjects, after 20 weeks of use

8X Stronger Skin*
*Cosmeto-clinical study, 51 subjects, after 20 weeks.