Hyperpigmentation vs Melasma: Different Conditions, Different Treatments
Dark patches and uneven skin tone are among the most searched skincare concerns, and the two terms people use most — hyperpigmentation and melasma — are often used as if they were interchangeable. They are not. Melasma is a specific, hormonally-driven form of pigmentation with distinct characteristics, triggers, and treatment requirements. Hyperpigmentation is a broader umbrella term covering multiple different types of excess melanin deposition — each with different causes. Using the wrong treatment for the wrong type of pigmentation is one of the main reasons people feel like brightening products never work for them.
Quick Answer
Hyperpigmentation is excess melanin deposition from any cause — sun exposure, inflammation, injury. Melasma is a specific chronic pigmentation condition driven by hormonal fluctuation (oestrogen, progesterone) combined with UV exposure, affecting the deeper dermis as well as the epidermis. Post-inflammatory hyperpigmentation (PIH) responds well to tyrosinase inhibitors and exfoliants. Melasma requires the same ingredients but is far more persistent, because the trigger — hormonal fluctuation — recurs continuously. SPF is non-negotiable for both, but for melasma it is the most important single intervention.
Types of Hyperpigmentation: A Framework
Lumping all dark spots together as "hyperpigmentation" obscures meaningful clinical differences. The main categories:
Post-inflammatory hyperpigmentation (PIH) occurs when inflammation — from acne, eczema, an insect bite, a wound, or any other skin injury — triggers melanocytes to overproduce melanin as a response to the inflammatory signal. It appears as a flat dark mark at the site of the previous lesion. PIH is more common and more severe in skin with higher baseline melanin content (Fitzpatrick types III–VI) and is a significant concern for people with acne-prone skin of colour. It is epidermal (surface-level) in most cases, making it responsive to topical treatment.
Solar lentigines (sun spots, age spots) are discrete flat patches caused by chronic UV exposure, distinct from freckles (which are genetic). They appear on the most sun-exposed areas — face, hands, décolletage — and tend to appear or worsen with age as cumulative UV damage accumulates. They are epidermal and respond to both topical brightening ingredients and in-office treatments.
Melasma is covered in its own section below — it is the most complex and treatment-resistant of the three.
What Is Melasma?
Melasma is a chronic pigmentation disorder characterised by symmetrical, irregular brown or grey-brown patches — most commonly on the cheeks, forehead, upper lip, and chin, in a characteristic distribution. Unlike PIH, which appears at the site of a specific previous injury, melasma has no single precipitating incident. It is driven by two co-factors that must both be present: hormonal stimulation and UV exposure.
Oestrogen and progesterone stimulate melanocytes to produce more melanin, and UV exposure activates those primed melanocytes. This is why melasma is far more common in women (particularly during pregnancy — when it is called the "mask of pregnancy" or chloasma — and in those on hormonal contraceptives) and why it improves in winter and worsens dramatically with sun exposure. Men can develop melasma, but at significantly lower rates.
Critically, melasma involves both epidermal and dermal melanin deposition. Epidermal pigmentation responds to topical treatment. Dermal pigmentation — in the deeper dermis — is much more resistant, because topical products penetrate poorly to that depth, and because the melanin there is inside macrophages (immune cells) rather than in the epidermis where normal desquamation would eventually clear it. This dual-layer nature is the primary reason melasma is so much harder to treat than PIH.
How to Tell Them Apart
| Feature | Post-Inflammatory Hyperpigmentation | Solar Lentigines | Melasma |
|---|---|---|---|
| Pattern | Follows previous lesion site exactly | Discrete round/oval spots | Symmetrical, diffuse patches — cheeks, forehead, lip |
| Trigger | Skin inflammation or injury | Cumulative UV exposure | Hormones + UV (both required) |
| Who gets it | Any skin type; more severe in darker tones | Any skin type; more visible in lighter tones | Predominantly women; hormonal contraceptives; pregnancy |
| Depth | Epidermal (surface) | Epidermal | Epidermal + dermal (mixed) |
| Seasonality | Stable, may fade with time | May darken in summer | Markedly worse in summer, may fade in winter |
| Treatment response | Good with topical actives | Good with topical + in-office | Partial — requires ongoing management |
| Recurrence | Returns if inflammation recurs | New spots with ongoing sun exposure | Chronic — very likely to recur even after treatment |
Treating Post-Inflammatory Hyperpigmentation
PIH treatment follows a clear logic: inhibit new melanin synthesis, accelerate clearance of existing pigmented cells through exfoliation, and prevent UV-triggered darkening. The most effective OTC approach combines multiple mechanisms simultaneously.
Tyrosinase inhibitors reduce melanin production at the synthesis stage: niacinamide (which also inhibits melanosome transfer), azelaic acid (10% OTC), vitamin C (L-ascorbic acid and derivatives), and kojic acid. Tranexamic acid addresses the upstream signalling that triggers melanin overproduction. For a deeper look at tranexamic acid's mechanism, see our full tranexamic acid guide.
Chemical exfoliation accelerates surface cell turnover, clearing pigmented cells faster than they would shed naturally: AHAs (glycolic, lactic) are the most effective for surface PIH. See our guide to fading acne scars and PIH for a step-by-step approach.
SPF daily. UV darkens existing PIH and triggers new melanin production. Every brightening ingredient works against the current of ongoing UV exposure without consistent SPF.
Treating Melasma
Melasma treatment uses the same ingredient toolkit as PIH but requires different expectations and a stronger emphasis on trigger management. Because the hormonal trigger is persistent — particularly if you are on hormonal contraceptives or pregnant — topical treatment is managing the condition rather than curing it.
The most evidence-backed topical approach for melasma is the triple combination: hydroquinone 4% (prescription in most countries), tretinoin, and a mild corticosteroid — the Kligman formula. Hydroquinone is the gold standard tyrosinase inhibitor, with the strongest evidence base for melasma of any topical ingredient, but it requires medical supervision, carries a risk of irritation and ochronosis with prolonged use, and is a short-term (3–6 month) rather than indefinite treatment. In countries where hydroquinone is OTC at lower percentages, it remains a valid option for short-term use.
For OTC approaches, tranexamic acid is the strongest candidate — multiple clinical trials show meaningful MASI (Melasma Area Severity Index) improvement at 2–5% topical over 8–12 weeks, with a significantly better tolerability profile than hydroquinone. Combining tranexamic acid with niacinamide and vitamin C addresses the condition through three complementary brightening mechanisms simultaneously. Azelaic acid at 15–20% (prescription) also has clinical evidence specifically for melasma and is considered safe during pregnancy — making it one of the few evidence-backed melasma treatments for that context.
SPF is not just important for melasma — it is the most important single intervention. UV exposure is the co-trigger without which the hormonal stimulus alone does not activate melasma. Broad-spectrum SPF 50, applied daily and reapplied during UV exposure, has a larger impact on melasma control than any topical brightening ingredient. Mineral sunscreens with zinc oxide provide some additional benefit for melasma because they reflect visible light (particularly blue light), which can also stimulate melanocytes in melasma-prone skin — a benefit that purely UV-absorbing chemical sunscreens do not provide.