Dark marks, melasma and uneven tone

What causes dark marks, melasma and sun spots?

Dark patches on the face have three common causes: marks left behind by inflammation, melasma driven by light and hormones, and sun spots from years of exposure. Post-inflammatory hyperpigmentation is the brown or grey mark left behind after a spot, a scratch or a reaction. It fades on its own, slowly, over months. Melasma is symmetrical patchy pigmentation, usually on the cheeks, forehead and upper lip, driven by a combination of sun, heat, visible light and hormones, which is why the British Association of Dermatologists notes it is common in pregnancy and with the contraceptive pill. Sun spots, or lentigines, are the flat brown marks that accumulate on the face, chest and backs of hands over years of exposure. Darker skin tones produce pigment more readily, so marks left by inflammation are more common in darker skin.

What makes pigmentation worse?

Ultraviolet light makes every type of pigmentation worse, and nothing else comes close. For melasma, heat and visible light matter too, including the light from being outdoors on an overcast day. Picking and squeezing spots reliably makes the mark worse and longer lasting than the spot itself. Aggressive treatment can also backfire, since irritation causes inflammation and inflammation causes pigment.

Which skincare ingredients help fade dark marks?

Daily broad-spectrum sunscreen matters more than any fading ingredient, because you cannot lighten a mark while the sun keeps darkening it. Without it nothing else works. The NHS advice on sunscreen is at least SPF 30 with at least 4-star UVA protection. For melasma specifically, a tinted sunscreen containing iron oxides also blocks visible light, which plain sunscreens do not, and in a 2014 randomised trial people with melasma who used one did better than those using a UV-only sunscreen. Then the evidence-backed ingredients for the look of uneven tone: vitamin C, niacinamide, azelaic acid, alpha arbutin, topical tranexamic acid, and retinoids to speed cell turnover. Expect months rather than weeks, and expect melasma to return with sun exposure. A MyAgenix read builds a routine around sunscreen and the tone ingredients that suit your skin, and leaves out the ones that clash.

What can a doctor prescribe for melasma and dark marks?

A doctor can prescribe hydroquinone, the most studied lightening agent, which in the UK can only be prescribed by doctors and is used in short courses under supervision. Dermatologists also use combination creams, oral tranexamic acid in selected cases, chemical peels and lasers; a 2024 meta-analysis of 22 trials found tranexamic acid helped melasma, with tablets showing the largest effect. Lasers need care with melasma and with darker skin tones, where the wrong device or setting can make pigmentation worse rather than better, a risk a 2022 review of melasma treatments flags for peels and lasers alike. Choose a practitioner who treats your skin tone regularly.

When should a dark spot on your skin be checked by a GP?

See a GP promptly about any new pigmented spot that is changing in size, shape or colour, has an uneven edge or more than one colour, itches or bleeds, as these are signs the NHS lists for melanoma. That is a skin cancer check, not a cosmetic question, and it is the one thing on this page we would ask you not to sit on.

General information about skin, not medical advice. MyAgenix offers cosmetic guidance to help you choose products. It does not diagnose or treat any condition. For anything on this page that needs treating, see a pharmacist, your GP or a dermatologist.