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 age spots?
Age spots – known clinically as solar lentigines, and sometimes as liver spots – are flat, well-defined brown or tan patches that appear on skin with the most cumulative sun exposure: the face, backs of the hands, forearms, shoulders and upper chest.
Despite the name, they are not caused by age itself. They are a record of ultraviolet exposure, which is why they are common from the forties onward and why they cluster on areas that rarely get sunscreen.
What causes age spots?
Long-term UV exposure drives melanocytes to over-produce melanin in concentrated spots, and the surrounding keratinocytes stop clearing that pigment efficiently as skin ages.
Fair skin, a history of sunburns, tanning beds and outdoor work all raise the risk. Any new spot that changes shape, colour or size, bleeds or has an irregular border should be checked by a doctor rather than treated cosmetically.
What ingredients are best for age spots?
Topical treatment works but needs patience – expect three to six months. Retinoids speed turnover so pigmented cells shed faster, vitamin C and niacinamide brighten and protect, and alpha arbutin, kojic acid, azelaic acid and liquorice root inhibit new pigment.
Glycolic or lactic acid helps lift existing pigment from the surface. Daily broad-spectrum SPF, including on hands and chest, is what prevents new spots forming. Take our Skin Quiz.
