What is PHA in skincare?
PHA stands for polyhydroxy acid, the newest generation of chemical exfoliants. The two you will see on labels are gluconolactone and lactobionic acid.
Their molecules are considerably larger than AHAs, so they sit on the surface and exfoliate slowly rather than penetrating quickly. That makes them the gentlest option in the acid family – studies show anti-ageing results comparable to AHAs with noticeably less irritation.
What skin concerns do PHAs treat?
PHAs suit dullness, rough texture, uneven tone and early fine lines on skin that cannot tolerate glycolic or salicylic acid – including rosacea-prone, eczema-prone and generally reactive skin.
They are also humectants, so they hydrate as they exfoliate, and gluconolactone is an antioxidant that protects against UV-induced damage in laboratory models.
What ingredients are best paired with PHAs?
Because they are mild, PHAs layer comfortably with niacinamide, hyaluronic acid, ceramides and peptides, and they are often used to introduce exfoliation alongside a retinoid without overwhelming the barrier.
Follow with a moisturiser and daily SPF as with any exfoliant. If stronger acids have left your skin stinging or flushed, swapping to a PHA is usually the sensible step down. Take our Skin Quiz.
What is rosacea?
Rosacea is a chronic inflammatory skin condition that affects the central face – cheeks, nose, chin and forehead. It presents as persistent redness, visible broken capillaries, flushing that comes and goes, and in some subtypes acne-like papules and pustules.
Unlike acne, rosacea involves no comedones. It is driven by a combination of vascular hyper-reactivity, neurogenic inflammation and an overactive innate immune response, often with an impaired skin barrier alongside.
What causes rosacea?
There is no single cause. Genetic predisposition, an exaggerated immune response involving cathelicidin, overgrowth of Demodex mites, and dysfunction of the facial blood vessels all appear to contribute.
Flares are triggered by heat, sun exposure, alcohol, spicy food, hot drinks, exercise, stress, wind and cold, and by harsh skincare. Identifying and avoiding your own trigger set does as much as any product.
What ingredients are best for rosacea?
Azelaic acid and niacinamide are the standout actives – both reduce redness and inflammation without provoking the barrier. Sulphur, green tea extract, liquorice root and centella asiatica also calm reactive skin.
Build everything else around barrier repair: ceramides, glycerin, squalane and panthenol, with a gentle non-foaming cleanser and a mineral SPF every day. Avoid alcohol-heavy toners, fragrance, menthol, physical scrubs and high-strength acids. Take our Skin Quiz to build a routine your skin will tolerate.
