What is hyaluronic acid in skincare?
Hyaluronic acid is a glycosaminoglycan that occurs naturally in skin, joints and connective tissue. It is a humectant of remarkable capacity, able to hold many times its own weight in water, which is why it sits in the hydrating step of almost every modern routine.
Molecular weight determines behaviour: high-molecular-weight HA forms a moisture-holding film on the surface, while low-molecular-weight fragments penetrate further for hydration in the deeper epidermis. Good formulas blend several weights.
What skin concerns does hyaluronic acid treat?
It addresses dehydration in any skin type, including oily and acne-prone skin that cannot tolerate heavy oils. Hydrated skin cells sit plumper against one another, which immediately softens the look of fine lines and improves how the face reflects light.
It also supports barrier function and wound healing, and it makes stronger actives – retinoids, acids – far more tolerable by keeping the skin comfortable alongside them.
What ingredients are best paired with hyaluronic acid?
Hyaluronic acid pulls water in but cannot hold it there alone, so always seal it with an occlusive or emollient: ceramides, squalane, shea butter or a simple moisturiser applied straight after.
It layers well with almost everything – vitamin C, niacinamide, retinoids, peptides and AHAs. Apply it to damp skin, and in a very dry climate keep a moisturiser over the top, or it can draw moisture out of the skin rather than into it. Take our Skin Quiz.
What is melasma?
Melasma is a common form of acquired hyperpigmentation that appears as symmetrical brown or greyish-brown patches, most often across the cheeks, forehead, upper lip and jawline. It develops when melanocytes – the pigment-producing cells in the skin – become overactive and deposit excess melanin into the epidermis, the dermis, or both.
It is far more common in women and in medium to deeper skin tones, and it behaves as a chronic, relapsing condition rather than a one-off mark – which is why management matters as much as treatment.
What causes melasma?
Three triggers dominate: ultraviolet and visible light exposure, hormonal change (pregnancy, oral contraceptives and hormone therapy – hence its nickname, the mask of pregnancy), and genetic predisposition.
Heat, visible light from sunlight and screens, inflammation from harsh products or aggressive procedures, and certain medications all make existing patches worse. Because the triggers are ongoing, melasma typically fades and returns rather than clearing permanently.
What ingredients are best for melasma?
Daily broad-spectrum sunscreen is non-negotiable, and a tinted mineral SPF containing iron oxides is best because it also screens the visible light that drives pigment production.
On top of that, the most evidence-backed actives are tranexamic acid, azelaic acid, niacinamide, vitamin C, alpha arbutin, kojic acid, liquorice root extract, retinoids and gentle alpha-hydroxy acids. Avoid harsh scrubs and strong heat, both of which can rebound the pigment. Take our Skin Quiz to build a routine around your skin tone and triggers.