By: Cosmecell
This article is educational and not a substitute for a diagnosis from a dermatologist. Melasma in particular can be difficult to self-identify accurately, and getting the diagnosis right changes what actually helps.
"Hyperpigmentation" Is a Category, Not a Diagnosis
Hyperpigmentation is an umbrella term for any patch of skin that's darker than the surrounding area. It's not one condition — it's a description of an outcome that several different underlying causes can produce. Melasma is one specific cause of hyperpigmentation, not a synonym for it. Knowing which type you're actually dealing with matters, because the three most common causes respond differently to treatment.
The Three Most Common Types
Post-Inflammatory Hyperpigmentation (PIH)
PIH shows up after skin inflammation — most commonly acne, but also cuts, burns, eczema flares, or aggressive extractions. It appears as a flat, discolored mark left behind where the inflammation was, and it typically fades on its own over months, though that process can be sped up with the right actives and consistent sun protection.
Solar Lentigines (Sun Spots / Age Spots)
These develop from cumulative UV exposure over years, typically appearing as small, well-defined spots on areas that get the most sun — face, hands, shoulders. They're a direct result of sun damage and tend to be stable rather than spreading, though new ones can form with continued unprotected exposure.
Melasma
Melasma is different in pattern, cause, and difficulty. It typically appears as larger, symmetrical, blotchy patches — often across the cheeks, forehead, upper lip, or bridge of the nose — rather than small, isolated spots. It's strongly linked to hormonal factors (pregnancy, birth control, hormone therapy) alongside UV exposure, which is why it's sometimes called "the mask of pregnancy." Melasma is notoriously more resistant to treatment than PIH or sun spots, and it commonly recurs even after it appears to have cleared, especially with sun or hormone triggers.
Why the Distinction Changes Your Approach
PIH and solar lentigines generally respond well to the same category of ingredients: azelaic acid, vitamin C, and consistent sun protection, used patiently over weeks to months. Melasma can respond to some of the same ingredients, but it's more likely to need a longer timeline, stricter sun protection, and in many cases, guidance from a dermatologist — sometimes involving prescription-strength options that go beyond what over-the-counter actives can do. Treating melasma like ordinary PIH, and expecting the same timeline, is one of the most common sources of frustration people run into.
Where an Ingredient-Focused Routine Fits
For PIH and sun spots, a routine built around azelaic acid and vitamin C — layered with daily sunscreen — is a reasonable, well-supported starting point. Cosmecell's Azelaic Acid Serum (with HPPA and hyaluronic acid) targets uneven tone and post-blemish marks while being gentle enough for sensitive or blemish-prone skin. The Vitamin C Serum (12% ascorbic acid, alpha arbutin, polyglutamic acid) adds antioxidant support and a second angle on tone.
If you suspect what you're dealing with is melasma — especially if it appeared or worsened during pregnancy, started or changed with hormonal birth control, or shows the larger, symmetrical, mask-like pattern described above — it's worth getting a dermatologist's read before building a routine around it. The same ingredients can still play a supporting role, but melasma often needs more than an OTC routine alone, and a professional can rule out other causes and set realistic expectations for timeline.
The One Step That Matters for All Three
Daily, consistent sunscreen is the single most important step regardless of which type of hyperpigmentation you're dealing with. UV exposure is what triggers PIH to darken further, what causes solar lentigines in the first place, and what reliably worsens and re-triggers melasma. No serum routine outperforms inconsistent sun protection.
The Takeaway
Not all dark spots are the same problem. PIH and sun spots generally respond to a patient, ingredient-led routine plus sunscreen. Melasma is a different, more stubborn condition that often benefits from a dermatologist's involvement alongside that same routine. Getting the type right is the first real step toward treating it effectively. See the Azelaic Acid Serum or see the Vitamin C Serum.