Glycolic acid is one of the most widely used skincare acids, in face washes, toners, serums and clinic peels. Used well, it is a reliable way to brighten and smooth skin. Used too eagerly, it irritates. Here is how to get the benefits without the trouble.
What it is
Glycolic acid is an alpha hydroxy acid (AHA), originally derived from sugarcane. It has the smallest molecule of the AHAs, so it penetrates the surface layer of the skin easily. There it loosens the bonds between dead skin cells, so they shed more evenly.
What it can help with
- Dullness and rough texture: smoother, brighter-looking skin.
- Uneven tone and mild pigmentation: gradual fading of dark marks, alongside sunscreen.
- Clogged pores and mild acne: less build-up in pores.
- Fine lines: modest improvement with long-term use.
It works gradually: expect changes over four to eight weeks.
How to start
- Choose a low-strength product (around 5 to 8 per cent) as a toner, serum or leave-on lotion.
- Use it at night, two or three times a week, on clean, dry skin.
- Follow with a simple moisturiser.
- Wear sunscreen every morning: AHAs make skin more sensitive to the sun.
- Increase frequency slowly if your skin stays comfortable.
A glycolic face wash is a gentle way to begin, because it stays on the skin only briefly.
Side effects and who should be careful
Mild tingling is common at first. Stop or reduce use if you get stinging, redness, peeling or burning. Take extra care, or ask a dermatologist first, if you have:
- sensitive skin, eczema or rosacea;
- active sunburn or broken skin;
- recently used isotretinoin or strong retinoids;
- a history of pigment problems after irritation, common in brown skin.
Do not combine several strong exfoliants (glycolic, salicylic, retinoids, scrubs) on the same night.
Glycolic vs other acids
- Lactic acid: another AHA, larger molecule, gentler; good for dry or sensitive skin.
- Mandelic acid: a larger AHA, often well tolerated by darker skin.
- Salicylic acid: a BHA that dissolves in oil, so it is better for blackheads and oily, acne-prone skin.
Clinic glycolic peels
In the clinic, glycolic acid is used at higher strengths as a superficial chemical peel, applied for a set time and then neutralised. A series of peels can give faster, more noticeable brightening than home products, with supervision of the strength and timing for your skin. See chemical peels.
If you are unsure where to start, a dermatologist can suggest the right acid, strength and routine for your skin.
