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 oily skin?
Oily skin is a skin type in which the sebaceous glands produce more sebum than the skin needs. It shows up as shine through the T-zone within hours of cleansing, visibly enlarged pores, makeup that slides or separates, and a tendency towards blackheads and congestion.
Sebum itself is not the enemy – it carries vitamin E to the surface, keeps the barrier supple and helps oily skin hold its structure, which is why it often shows fine lines later than dry skin does.
What causes oily skin?
Genetics and androgen activity are the primary drivers of how much sebum your glands produce. Heat and humidity increase output measurably, and hormonal fluctuations across the monthly cycle, pregnancy or puberty shift it again.
Stress, a diet heavy in refined carbohydrates, and – counter-intuitively – over-cleansing with stripping foams or alcohol-based toners all push oil production up, because skin compensates for a damaged barrier by making more.
What ingredients are best for oily skin?
Look for salicylic acid (a BHA that is oil-soluble, so it clears inside the pore), niacinamide and zinc to regulate sebum, clay such as bentonite or kaolin for weekly absorption, and retinoids or azelaic acid to normalise how pores shed.
Do not skip hydration: lightweight humectants like hyaluronic acid and glycerin, plus non-comedogenic squalane or jojoba oil, keep the barrier intact so the skin stops over-compensating. Skip heavy occlusive balms and high-alcohol toners. Take our Skin Quiz to get the balance right for your skin.