Glycolic Acid

What is the summary?

• Glycolic acid is an Alpha Hydroxy Acid
• It can be used as a clinical peel in concentrations of 20%-70%
• Glycolic acid skin care ranges from 5% to 16%, in a higher pH
• Glycolic acid’s role is to exfoliate the skin
• Exfoliation improves skin luminosity & brightness
• Exfoliation also potentiates the absorption of other topicals
• Glycolic acid is one of our favorite ingredients used for melasma pigment

What is glycolic acid?

Glycolic acid is a type of alpha hydroxy acid (AHA) derived from sugarcane, known for its ability to exfoliate the skin. It works by breaking down the bonds between dead skin cells, promoting cell turnover and revealing fresher, brighter skin underneath.

 Due to its small molecular size, it penetrates deeply into the skin, making it effective for treating various skin concerns such as hyperpigmentation, fine lines, acne scars, & uneven texture. 

Why should you use it for pigmentation & melasma?

AHAs exfoliate the dead skin cells to reveal fresher skin. This reduces pigment in the upper layers of skin. Glycolic acid also increases the absorption of other pigment correctors. 

Overall, it is harder to use glycolic acid (properly) compared to daily pigment correctors, however if you master ‘pulsed’ therapy it accelerates your treatment program. 

How good is it for pigment & what types of pigment can glycolic acid treat?

Glycolic acid ranks in one of our top 7 ingredients for pigmentation. It can potentially treat the following types of pigmentation. 

• Melasma
• Post inflammatory hyperpigmentation
• Sun & age related pigmentation
• Acanthosis nigricans, mixed pigment
• Ethnic skin lightening & brightening

How long does it take for glycolic acid to work?

Glycolic acid is one of the fastest acting ingredients, especially in concentrations of over 20%.  Results are seen at about 2 to 4 weeks, however it may take up to 6-8 weeks for maximal effects. 

How often should I use glycolic acid?

Glycolic acid can be used via 3 ways. The best way depends on your aims, your skin sensitivity & your current skin care routine. 

1. Nightly. Most popular with many, least favorite in our opinion. The disadvantage of this method is that the concentrations are neither low nor high. This middle ground is not great with combination treatments or as a stand-alone for meaningful exfoliation. 
2. With other skin care products (premixed), with HQ or novel formulations such as Melanopro peel. This can be used 1-3 times per day, depending on the formula. 
3. In a pulsed or skin cycling manner, once every 7 -10 days. Preferred as maintenance for skin lightening, anti-aging & keeping pigmentation away. The concentration of pulsed glycolic acid serum ranges from 15 to 18% in a moderately low pH formula. Cycling is best reserved when you understand your skin’s irritant potential & threshold. 

What is the difference between glycolic acid peels & glycolic acid serums?

pH & concentrations. In office clinical peels have a low pH with higher bioavailability of glycolic acid & much higher concentrations, ranging from 20 to 70%. These peels require neutralization. 

Home glycolic acid serums have lower concentrations, with the maximum of 16 to 18%, their pH is higher & the formulations are buffered. This prevents or reduces chemical burns.

How good is glycolic acid compared to retinol?

Glycolic Acid is an AHA that exfoliates the skin by dissolving the bonds between dead cells on the surface, leading to brighter, smoother skin. In contrast, retinol works deeper in the skin by increasing cell turnover and boosting collagen production, effectively treating acne, fine lines, and wrinkles. 

When it comes to exfoliation and brightening, glycolic acid excels by sloughing off dead skin cells. On the other hand, retinol is more versatile, offering stronger anti-aging benefits and improving overall skin health by addressing both surface and deeper skin concerns.

Glycolic Acid is best for those seeking surface-level improvements like texture and brightness, while Retinol is ideal for individuals targeting acne, fine lines, and signs of aging.

In summary, glycolic acid is your go-to for exfoliation & immediate radiance, while retinol is unmatched for long-term skin health and anti-aging. Many skincare routines benefit from incorporating both, depending on individual skin needs, acknowledging concerns with interactions. My recommendations? Stick with glycolic acid if you want to treat pigment, forget retinol for the time being. 

How good is glycolic acid compared vs salicylic acid?

Glycolic acid, an AHA, exfoliates the skin’s surface, improving texture, tone, & addressing signs of aging. It’s best suited for normal to dry skin. 

Salicylic acid, a BHA, penetrates deeper into pores, making it ideal for oily and acne-prone skin by clearing out clogs and reducing breakouts. Glycolic acid is more effective for pigment & anti-aging and overall skin smoothness, while salicylic acid excels in treating acne and preventing future breakouts. Both acids have their strengths, depending on the skin concern being addressed.

Does glycolic acid have any side effects?

There is a marked difference between side effects & expected outcomes. 

Expected effects include- mild stinging, transient redness, mild self-limiting peel. FFS, you are using a skin care product that is acidic with a low pH, of course you will experience the above. 

Side effects include burning, pain, prolonged swelling, redness & prolonged skin inflammation leading to a compromised skin barrier. If this occurs you have cooked it too long, used too much, mixed wrongly, or rarely, you are allergic to glycolic acid. 

If you suffer from rosacea, dermatitis, or reactive skin, we suggest you don’t play around with glycolic. Try mandelic acid instead. This has a larger molecular weight, so it penetrates less. 

Here is how to reduce side effects-

1. Start with a low concentration of glycolic 5-10%.
2. Mix this with moisturizer
3. Apply every second night to a small area at first (test spot)
4. Increase as tolerated. 

What is the best skin care acid for sensitive skin?

The best AHA for sensitive skin is mandelic acid. This sits at the other end of molecular weight, meaning less penetration 

The molecular weight of glycolic acid  is 76.05 g/mol, while mandelic acid has a molecular weight of 152.15 g/mol. This difference in molecular weight impacts their penetration ability in the skin, with glycolic acid being smaller and able to penetrate deeper and more quickly, while mandelic acid, being larger, is more gentle and works at the skin’s surface.

What is an example of a skin care routine using glycolic for treating melasma?

A simple melasma skincare routine is as follows: 

AM: Ascorbic acid, ferulic acid, SPF

Midday: Sunscreen reapplication, lotion, stick or spray.

PM: Glycolic acid 5-10% serum. 

Note: The greatest traction of any melasma skincare routine is the correct application of sunscreen. This has a much greater impact on melasma than any marketing objective of any skin care ingredient. 

What are the best formulations & brands of glycolic acid?

Here are Dr Davin Lim’s favorites.  

Best overall: Melanopro system, especially the Continuous Resurfacing Cream. This formulation by Dermalogica combines azelaic acid, niacinamide, t.acid, retinol & niacinamide with glycolic acid. It is a stand out formulation that reduces pigment, potentiates absorption of other topicals & reduces skin roughness. If there was a five star rating, I would give this product the gold medal. 

AHA Elucent: bang for your buck. The Elucent Anti-aging Serum contains 16% AHA, with 12% lactic & 4% glycolic. Awesome value for money, it is best used as a primer or in a pulsed manner. 

Paula’s Choice: selected by Paula, hence must be great. The 25% AHA & 2% BHA plays the numbers game. It’s refreshing to see that this company advocates pulse therapy. Recommend. 

Other highly recommended brands include Synergie ReVeal with 13% AHA & 2% BHA.  

However, it is twice as expensive as Elucent but equally as good. Rationale also makes great skin acids, however if you know Richard Parker’s formulations, they have been ‘watered down’ over the years to cater for mainstream skin care, rather than niche dermatology skin care. 

The Ordinary: is really ordinary, best used as a wash (cheap & nasty). It has its place. 

Is glycolic acid from The Ordinary any good?

The Ordinary produces really good wash off products such as squalene cleanser, however their leave on products such as the 7% Glycolic acid serum, is, quite frankly, very ordinary. 

The upside? It’s cheap at only $13.20 per 100 ml. Personally, my preferred concentration ranges from 12 to 18% as a higher concentration is more effective. 

*It’s not just the concentration that counts, it is the pH of the formulation. A lower pH is better, as this allows for higher bioavailability at the expense of skin irritation. With power, comes responsibility. The rate limiting factor for over the counter AHAs such as glycolic & lactic acids is the ability of the consumer to understand how to retrieve their skin past the point of skin irritation. 

What do the studies say about glycolic acid for melasma?

Here are some clinical studies related to the use of glycolic acid in the treatment of melasma:

Kalla G, Garg A. (1996): In a study published in the “Indian Journal of Dermatology, Venereology, and Leprology,” researchers evaluated the efficacy of glycolic acid peels in the treatment of melasma. The study found that glycolic acid peels significantly improved melasma in patients, showing a reduction in pigmentation intensity and surface area involved.

Sarkar R, Bansal S, Garg VK. (2002): Another study, published in the “Journal of Cosmetic Dermatology,” compared the efficacy of glycolic acid (30-70%) with salicylic acid (20-30%) in melasma treatment. Glycolic acid was shown to be effective in reducing melasma pigmentation with fewer side effects compared to other chemical peels.

Grimes PE. (1999):  In a study featured in “Cutis,” Pearl investigated the efficacy of a combination of glycolic acid and hydroquinone in treating melasma. The combination was found to significantly reduce hyperpigmentation, highlighting the synergistic effect of these agents in treating melasma.

These studies collectively show that glycolic acid, particularly when used in combination with other agents like hydroquinone, can be an effective treatment for melasma, offering significant improvement in pigmentation and overall skin appearance. 

The Melasma Clinic supports combination therapy, acknowledging that the rate limiting factor is the patient’s understanding of their skin’s threshold for irritation. Combination therapy is always more effective, however with increased efficacy comes increased skin irritation. 

Does glycolic acid lighten skin?

Daily use of glycolic acid is a good way to lighten & brighten skin, especially in combination with lactic, salicylic & tranexamic acids. 

Facial skin lightening & pigmentation reduction can be achieved with combination acids in the Melanopro peel system for a period of 6 weeks. 

Body lightening can be achieved with 3-10% glycolic acid cream, applied in a pulsed manner with salicylic acid washes. 

*Best achieved with supplements including glutathione & polypodium.

Are  glycolic acid peels the best for melasma pigmentation?

Though glycolic peels are useful for melasma (especially in combination with other skin care actives), we prefer novel formulations of peeling agents. These peels include-

• Cosmelan
• Dermamelan
• Vi Precision Plus
• Melanopro peel system

In our experience novel peels are far more effective in melasma, however glycolic acid peels are very good for non-melasma pigmentation, especially sun damage. 

Can I use glycolic acid long term?

Unlike hydroquinone, glycolic acid can be used long term without any complications. The choice of nightly use or pulsed therapy depends on your clinical presentation. 

Used in pulse therapy glycolic acid provides strong exfoliation at intervals (my preferred method). In contrast, used nightly it provides mild exfoliation. Nightly use is easier to modulate compared to pulsed therapy. 

Can I use glycolic acid after pico laser?

Yes, glycolic acid potentiates the effects of pico laser, especially for skin lightening, brightening, pigment resolution & melasma. Your clinician will give you instructions on the exact timing of use. 

As a guide you can recommence glycolic acid 2-6 days after pico. Continued use will augment the results from the laser. 

Can glycolic acid be used in pregnancy?

Yes, glycolic, lactic, mandelic & azelaic acids can be safely used in pregnancy. Niacinamide is also safe in pregnancy.

Ingredients not recommended in pregnancy include: Vitamin A / retinol/retinoids, hydroquinone.