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 are dark spots?
Dark spots are localised patches where the skin has produced more melanin than the surrounding area. The umbrella term covers sun spots, post-acne marks, melasma patches and freckles – different causes, same visible result.
They are flat rather than raised, vary from light tan to deep brown, and are most noticeable on the face, hands and chest. In deeper skin tones they tend to be darker and to last considerably longer.
What causes dark spots?
Two mechanisms dominate. Ultraviolet exposure triggers protective melanin production, and inflammation – from acne, ingrown hairs, eczema, friction, burns or harsh treatments – leaves post-inflammatory hyperpigmentation behind as it heals.
Hormonal change, some medications and heat add to it. Picking at spots is one of the most avoidable causes: the extra inflammation reliably makes the mark darker and longer-lived than the original blemish.
What ingredients are best for dark spots?
Vitamin C, niacinamide and azelaic acid are the everyday workhorses. For stubborn pigment, alpha arbutin, tranexamic acid, kojic acid and liquorice root extract interrupt melanin production directly.
Retinoids and gentle AHAs clear pigmented cells faster from the surface. Give any routine twelve weeks before judging it, and wear broad-spectrum SPF daily or the spots will simply redarken. Take our Skin Quiz.