Glycolic acid: for smoother skin and a fresh complexion

Does your skin feel rough and does your complexion look dull? A gentle peel with acid can support you in making it look smoother and fresher again. Glycolic acid is one such acid, you can find it in pads, toners and peels.

The key points in brief

• Glycolic acid loosens old cells on top of the skin so that they come away more easily.
• In two studies with creams, researchers saw small improvements in the appearance of the skin after 3 and 5 months.
• Start slowly and only increase once your skin tolerates the acid well.
• Sun protection is a must, because the acid makes your skin more sensitive to the sun.

What does glycolic acid do in the skin?

Glycolic acid is a fruit acid, AHA for short. That stands for alpha hydroxy acid. It is the simplest acid in this group.

Right on top of your skin lies the horny layer. These are old cells that stick firmly to each other. The acid loosens this hold, so the old cells come away more easily. Exactly how this works has not yet been established.

In a small study with 6 volunteers, a solution with 12 % glycolic acid stayed on the skin for 60 minutes each on 10 days. The horny layer renewed itself faster than with plain water. However, the skin also became red and drier in the process.

Who is it suitable for?

Glycolic acid suits you if your skin feels rough or your complexion looks dull.

Is your skin prone to shine and blemishes? Then pads that combine glycolic acid with salicylic acid suit you.

If your skin is sensitive, start with a mild toner or a peel without rubbing.

Who is it less suitable for?

If your skin is currently irritated, sore or injured, leave out the acid. This is stated in the manufacturers' instructions.

If you are planning many hours in the sun, for example on holiday, now is not a good time to start. According to the warnings of all four products below, your skin can become more sensitive to light.

Pregnancy and breastfeeding: please consult your doctor.

How to use it

This is how you proceed with the Complexion Renewal Pads:

1. Cleanse your face.
2. Gently sweep a pad over your face and neck, avoiding the eyes.
3. Do not rinse off.
4. Start with one pad in the evening.
5. If your skin tolerates this well, you use the pads morning and evening.
6. Apply sun protection with sun protection factor 30 or higher every day.

You start the Exfoliation Accelerator with 2 to 3 applications a week, the Enzymatic Peel you use 1 to 2 times a week. The Calming Toner you use morning and evening. For pads and toner, according to the warning: in case of strong irritation, use less often or pause.

Good to combine, better not together

Good together:

• Salicylic acid: both are found together in the Complexion Renewal Pads.
• Lactic acid: a second fruit acid, it is also in the Exfoliation Accelerator.
• Hyaluronic acid and panthenol: they give moisture, the Calming Toner already contains them.

Better not together:

• Retinol on the same evening as a peel: according to the information for Exfoliation Accelerator and Enzymatic Peel, this is too much for the skin.
• Two peels on the same day: according to the directions for use, Exfoliation Accelerator and Enzymatic Peel belong on different days.

What you can expect

In a study with 75 volunteers, one group applied a cream with 5 % glycolic acid to the face and neck every day for 3 months, the other group a cream without the active ingredient. With glycolic acid, the researchers afterwards saw a finer skin texture and less discolouration. For wrinkles, they saw only a trend, no reliable difference.

In a second study with 74 women between 40 and 70 years of age, one group applied a cream with 8 % glycolic acid twice a day for 22 weeks. The others used a cream with lactic acid or without the active ingredient. With glycolic acid, the signs of sun on the face were rated at least one level milder in 76 of 100 women. With the cream without the active ingredient, it was 40 of 100.

The researchers themselves describe the benefit as modest. Each result applies to the cream tested. We do not know the amount of acid in our products.

In a study with 29 volunteers, 10 % glycolic acid or a solution without the active ingredient was applied to the back on 6 days a week for 4 weeks. With glycolic acid, the skin then reacted more sensitively to UV light. One week after the end, there was no longer any difference in the 16 people measured again.

In our shop

You can find all products in our Glycolic acid collection. These four contain glycolic acid according to their ingredient list:

• Exfoliation Accelerator from ZO Skin Health: peel with glycolic acid in second place among the ingredients and lactic acid.
• Enzymatic Peel from ZO Skin Health: glycolic acid with enzymes from papaya and pineapple, without rubbing.
• Complexion Renewal Pads from ZO Skin Health: pads with glycolic acid and salicylic acid for every day.
• Calming Toner from ZO Skin Health: mild toner with a little glycolic acid, plus hyaluronic acid and panthenol.

Frequently asked questions

What does glycolic acid do to the skin?

It loosens old cells in the top layer. This can make your skin feel smoother.

How often should you exfoliate your face?

That depends on the product. You start the Exfoliation Accelerator with 2 to 3 applications a week and, depending on tolerance, increase up to daily. You use the Enzymatic Peel 1 to 2 times a week.

What are AHA and BHA?

AHA means alpha hydroxy acid, which includes glycolic acid and lactic acid. Salicylic acid is often called BHA, for beta hydroxy acid. Technically, this is not correct, as it is structured differently. It dissolves in fat and is therefore suitable for sebum-rich skin.

Is glycolic acid safe during pregnancy?

Please consult your doctor.

Sources

1. Kornhauser A, Coelho SG, Hearing VJ (2010): Applications of hydroxy acids: classification, mechanisms, and photoactivity. Clinical, Cosmetic and Investigational Dermatology 3:135-142. DOI 10.2147/CCID.S9042, PMID 21437068.
2. Effendy I, Kwangsukstith C, Lee JY, Maibach HI (1995): Functional changes in human stratum corneum induced by topical glycolic acid: comparison with all-trans retinoic acid. Acta Dermato-Venereologica 75(6):455-458. DOI 10.2340/0001555575455458, PMID 8651024.
3. Thibault PK, Wlodarczyk J, Wenck A (1998): A double-blind randomized clinical trial on the effectiveness of a daily glycolic acid 5% formulation in the treatment of photoaging. Dermatologic Surgery 24(5):573-577. DOI 10.1111/j.1524-4725.1998.tb04209.x, PMID 9598014.
4. Stiller MJ, Bartolone J, Stern R et al. (1996): Topical 8% glycolic acid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlled clinical trial. Archives of Dermatology 132(6):631-636. PMID 8651713.
5. Kaidbey K, Sutherland B, Bennett P et al. (2003): Topical glycolic acid enhances photodamage by ultraviolet light. Photodermatology, Photoimmunology & Photomedicine 19(1):21-27. DOI 10.1034/j.1600-0781.2003.00013.x, PMID 12713551.