What is glycolic acid in skincare?
Glycolic acid is an alpha-hydroxy acid derived from sugar cane. It has the smallest molecular size of the AHA family, which lets it penetrate the stratum corneum more readily than lactic or mandelic acid – and makes it both the most effective and the most likely to sting.
It works by dissolving the bonds holding dead cells to the surface, so they shed evenly instead of accumulating. Cosmetic strengths run from around 5% to 10%, with professional peels going considerably higher.
What skin concerns does glycolic acid treat?
It is one of the best-evidenced ingredients for dullness, rough texture and uneven tone, and it visibly brightens within a few uses. Over longer periods it fades sun spots and post-acne marks, softens fine lines and helps clear congestion.
Regular use also stimulates collagen production and thickens the deeper epidermis, so the benefit is structural as well as surface-level.
What ingredients are best paired with glycolic acid?
Follow it with hyaluronic acid, ceramides, glycerin and panthenol to replace what exfoliation costs the barrier. Niacinamide is a good companion for tone, and vitamin C works well on alternate days.
Do not stack it with retinoids, BHAs or benzoyl peroxide in the same step unless your skin is well conditioned, and start at twice a week. Glycolic acid increases sun sensitivity, so daily SPF is essential. Take our Skin Quiz.
What is dullness?
Healthy skin reflects light evenly, which is what reads as bright and glowing. Dull skin does the opposite – it looks flat, ashy, grey or sallow, and makeup tends to sit on top of it rather than blend in.
Dullness is not a condition in itself but a visible symptom: a build-up of dead cells, dehydration and reduced microcirculation that together stop light bouncing cleanly off the skin’s surface.
What causes dull skin?
Dead skin cells that do not shed naturally accumulate on the surface and scatter light unevenly. Dehydration flattens those cells so they no longer sit plump against one another, and overly dry skin can damage the follicles and slow the production of collagen and sebum – all of which make the complexion look duller or ashier.
Lifestyle and environment do the rest. Sun exposure, pollution, smoking, alcohol, broken sleep and stress all accelerate free-radical damage, while cell turnover naturally slows with age, so skin loses the reflectivity it had in your twenties.
What ingredients are best for dullness?
Brightening dull skin comes down to three things: gentle exfoliation, consistent hydration and antioxidant protection. Vitamin C, alpha-hydroxy acids such as glycolic and lactic acid, salicylic acid, retinol and vitamin A, niacinamide, green tea extract, coenzyme Q10 and rosehip oil all help resurface, even out tone and defend against free radicals.
Hyaluronic acid and hydrolysed collagen plump the skin so it reflects more light, and daily broad-spectrum sunscreen prevents the UV damage that dulls the complexion in the first place. Take our Skin Quiz to find the exact combination your skin needs.
