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 redness?
Facial redness is visible dilation of the small blood vessels near the skin’s surface. It ranges from transient flushing that comes and goes, to persistent erythema across the cheeks and nose, to fixed thread veins that stay visible all the time.
Redness is a symptom rather than a diagnosis. It can signal rosacea, irritation, an over-exfoliated barrier, eczema, an allergic reaction or simply reactive skin that responds strongly to heat and stress.
What causes redness?
Most persistent redness traces back to a compromised barrier and heightened nerve sensitivity. When the barrier thins, irritants penetrate more easily and the skin mounts an inflammatory response to things it would normally tolerate.
Common aggravators: over-exfoliation, high-strength actives used too often, fragrance and essential oils, hot water, alcohol, spicy food, sudden temperature change, sun exposure and stress. Trying to treat redness with more actives usually deepens it.
What ingredients are best for redness?
Prioritise calming and rebuilding over correcting. Niacinamide, azelaic acid, centella asiatica, green tea extract, liquorice root, allantoin, bisabolol and colloidal oatmeal all reduce visible inflammation.
Then repair the barrier with ceramides, cholesterol, fatty acids, glycerin, panthenol and squalane, and protect it with a gentle mineral SPF. Strip the routine back to cleanser, moisturiser and sunscreen for a few weeks before reintroducing anything active. Take our Skin Quiz.
