Four different conditions look broadly the same in a mirror and respond to completely different things, which is why the right diagnosis is the most valuable part of any pigmentation plan.
Melasma asks for the most expert hand. It appears as symmetrical brown patches across the cheeks, forehead and upper lip, it is driven by hormones as much as by sun, and it is long-term. Heat and aggressive laser stir it up, so it is treated gently, with Cosmelan and careful home care that suppress pigment and keep the skin calm. Melasma is managed rather than cured, and with maintenance it can be substantially cleared and held.
Sun damage behaves quite differently. Discrete brown spots on the face, hands and chest, sitting where the sun has hit, and it responds well and often quickly to treatment.
Post-inflammatory pigmentation is the mark left behind after a spot or an injury. It fades on its own given time, and treatment speeds that up.
Regents Park Aesthetics identifies which you have before recommending anything, and offers the Cosmelan protocol, peels and microneedling for pigmentation at the Wimpole Street clinic, a few minutes from Bond Street station.