Understanding Melasma

Melasma is one of the most common causes of uneven facial pigmentation, particularly in women. It appears as larger, irregular patches of brown, grey-brown or tan pigmentation that usually develop gradually over months or years.

Unlike freckles or sun spots, melasma is not caused by one factor alone. Instead, it develops when several biological processes interact. Hormones, ultraviolet (UV) radiation, visible light, heat, genetics and inflammation can all increase melanocyte activity, encouraging the skin to produce excess melanin.

For many people, melasma can become a long-term condition that improves with treatment but may return when triggers are reintroduced. Understanding why it develops helps explain why successful management usually involves both skincare and ongoing sun protection rather than relying on a single treatment.

By understanding the biology behind melasma, you can make more informed decisions and develop realistic expectations about caring for your skin.

What Is Melasma?

Melasma is a chronic pigmentary disorder in which melanocytes produce more melanin than surrounding areas of skin.

Rather than appearing as small isolated spots, melasma usually develops as larger symmetrical patches with soft, indistinct borders.

Common locations include:

cheeks
forehead
bridge of the nose
upper lip
chin
jawline

The pigmentation usually develops on both sides of the face, creating a symmetrical appearance that helps distinguish melasma from many other forms of pigmentation.

Unlike inflammatory skin conditions, melasma usually causes no pain, itching or discomfort. Its primary effect is cosmetic, although many people find it emotionally frustrating because of its tendency to recur.

Why Does Melasma Develop?

Melasma develops when melanocytes become overactive.

In the previous lesson, you learnt that melanocytes naturally increase melanin production whenever the skin senses potential stress or damage.

With melasma, this response becomes exaggerated.

Instead of producing only enough melanin for protection, melanocytes continue producing excess pigment even after relatively small triggers such as sunlight or hormonal changes.

Researchers now understand that melasma involves much more than increased melanin production alone.

Changes may also occur within:

the skin barrier
small blood vessels
inflammatory signalling
oxidative stress pathways
communication between skin cells

These interacting processes help explain why melasma can be persistent and why treatment often requires several different strategies working together.

The Role of Hormones

Hormonal changes are one of the strongest recognised triggers for melasma.

This is why melasma often develops:

during pregnancy
while taking the oral contraceptive pill
during hormone replacement therapy
during periods of hormonal fluctuation

Although the exact mechanisms are still being investigated, hormones appear to make melanocytes more responsive to UV exposure and other environmental triggers.

This means that sunlight which previously caused little pigmentation may suddenly produce more noticeable dark patches once hormone levels change.

Because of this relationship, melasma is sometimes called the "mask of pregnancy", although pregnancy is only one of several possible triggers.

Not everyone who experiences hormonal changes develops melasma. Genetics appears to influence how sensitive each person's melanocytes are.

Why Sunlight Is Such a Powerful Trigger

Although hormones often initiate melasma, sunlight usually keeps it active.

Ultraviolet radiation stimulates melanocytes to produce more melanin as part of the skin's natural defence system.

In people with melasma, this protective response becomes exaggerated.

Even relatively short periods of UV exposure can reactivate pigment-producing cells, making previously faded patches become darker again.

Importantly, both UVA and UVB contribute to pigmentation.

Because UVA passes through clouds and window glass, pigmentation may continue developing even when people spend much of their day indoors near windows or while driving.

Daily broad-spectrum sunscreen therefore becomes one of the most important long-term management strategies.

Heat Can Also Contribute

Many people are surprised to learn that heat itself may worsen melasma.

Research suggests that prolonged heat exposure can stimulate inflammatory pathways within the skin, which may indirectly activate melanocytes.

Potential heat sources include:

hot climates
saunas
steam rooms
vigorous exercise
professional heat-based treatments
prolonged cooking over hot surfaces

Heat alone does not cause melasma, but it may increase pigmentation in susceptible individuals when combined with sunlight or hormonal influences.

This helps explain why some people notice worsening pigmentation during summer despite wearing sunscreen consistently.

Genetics Influence Risk

Not everyone exposed to hormones or sunlight develops melasma.

Family history plays an important role.

Researchers believe inherited differences affect how sensitive melanocytes are to hormonal and environmental signals.

This means two people may experience similar sun exposure, yet only one develops melasma.

Genetics cannot be changed, but understanding this inherited tendency helps explain why long-term prevention often becomes just as important as treatment.

Melasma Is Often Chronic

One of the most challenging aspects of melasma is its tendency to return.

Even after successful treatment, melanocytes often remain more reactive than before.

Future exposure to hormones, sunlight or heat may reactivate pigment production.

Rather than thinking about melasma as something that can simply be "removed", it is often more helpful to think of it as a condition that can be managed over time.

Consistent skincare, daily sun protection and reducing avoidable triggers help support longer-lasting improvement.

Understanding the Different Types of Melasma

Not all melasma develops in exactly the same way. The depth at which excess pigment is located influences how the pigmentation appears and how it responds to treatment.

Although melasma is often divided into three types, many people have features of more than one.

Epidermal Melasma

In epidermal melasma, most of the excess melanin remains within the epidermis, the outer layer of the skin.

The pigmentation usually appears:

light to medium brown
relatively well defined
more responsive to topical skincare and professional treatment.

Because the epidermis naturally renews itself over time, superficial pigment has a greater opportunity to gradually fade when melanocyte activity is reduced.

Dermal Melasma

In dermal melasma, pigment extends deeper into the dermis after melanin has moved beyond the epidermis.

Dermal pigment often appears:

blue-grey
less sharply defined
slower to improve.

Because the dermis does not renew itself like the epidermis, pigment located at this depth is generally much more persistent.

Mixed Melasma

Many people have both epidermal and dermal pigment.

This is known as mixed melasma and is considered the most common pattern.

Different parts of the same patch may respond at different rates, which helps explain why improvement is often gradual rather than uniform.

How Is Melasma Diagnosed?

Melasma is usually diagnosed through a clinical skin examination.

An experienced GP, dermatologist or skin therapist will assess:

the appearance of the pigmentation
its distribution
symmetry across the face
your medical history
hormonal influences
previous sun exposure
medications
family history.

In most cases, additional testing is not required because melasma has a characteristic appearance.

The Limitations of Wood's Lamp Examination

A Wood's lamp emits ultraviolet light that can sometimes make superficial pigmentation appear more obvious.

Historically it was used to estimate whether pigment was mainly epidermal or dermal.

Today, however, clinicians recognise that its usefulness is limited.

Mixed melasma is extremely common, and inflammation, skin tone and previous treatment can all affect what the Wood's lamp shows.

For this reason, management decisions are now based more on the overall clinical picture than on Wood's lamp findings alone.

Ingredients with the Strongest Evidence

Melasma usually responds best when several evidence-informed ingredients work together over time.

Rather than removing pigment directly, most ingredients reduce the processes that continually stimulate melanocytes.

Niacinamide

Niacinamide helps reduce the transfer of melanosomes from melanocytes into surrounding skin cells.

It also supports the skin barrier and helps reduce inflammatory signalling.

Vitamin C Derivatives

Vitamin C functions as an antioxidant while also helping regulate several steps involved in melanin production.

More stable vitamin C derivatives are often better tolerated during long-term use.

Azelaic Acid

Azelaic acid helps reduce excess melanocyte activity while also calming inflammation.

It is frequently recommended because it combines pigment-modulating and anti-inflammatory effects with generally good tolerability.

Tranexamic Acid

Tranexamic acid has become one of the most researched newer ingredients for melasma.

Rather than acting directly on pigment alone, it appears to reduce several signalling pathways involved in melanocyte activation.

Topical formulations are increasingly used, while oral tranexamic acid may be prescribed in selected cases under medical supervision.

Alpha Arbutin

Alpha arbutin is another topical ingredient supported by growing clinical evidence.

When used consistently, it may gradually improve melasma while offering an alternative to longer-term hydroquinone use for some clients.

Cysteamine

Cysteamine is a newer topical treatment with growing evidence for melasma. It works by reducing several steps involved in melanin production and may be recommended by dermatologists or skin clinicians when appropriate. Although highly effective for some people, it is currently less common in everyday skincare products than ingredients such as niacinamide, vitamin C or alpha arbutin.

Retinoids

Retinoids support normal epidermal renewal and may improve penetration of other active ingredients.

Prescription-strength retinoids often form part of dermatologist-directed treatment plans, while cosmetic retinoids may provide more gradual support over time.

Hydroquinone: Why Medical Supervision Matters

Hydroquinone remains the prescription medicine with the strongest evidence for treating melasma and has been used for many decades.

It works by reducing melanin production within melanocytes.

However, hydroquinone is not intended for continuous long-term use.

Extended unsupervised use may increase the risk of skin irritation and, in rare cases, ochronosis—a blue-black discolouration of the skin.

For this reason, hydroquinone is generally prescribed by medical practitioners for defined treatment periods, often alongside retinoids, corticosteroids or other therapies, before transitioning to long-term maintenance with alternative ingredients.

Professional Treatments

For some people, professional treatment may complement an effective skincare routine.

Options may include:

superficial chemical peels
prescription topical medications
limited laser or light-based treatments
oral medications in carefully selected patients.

No professional treatment permanently cures melasma.

Success depends on choosing appropriate therapies while continuing strict sun protection afterwards.

Aggressive treatments can sometimes worsen pigmentation by triggering additional inflammation.

For this reason, treatment should be individualised rather than pursuing the strongest procedure available.

Pregnancy and Melasma

Because hormonal changes commonly trigger melasma, pigmentation often develops or worsens during pregnancy.

Many cases gradually improve after pregnancy, although some pigmentation may persist.

During pregnancy, treatment options become more limited because several commonly used ingredients are not recommended. After pregnancy a wider range of treatment options can be considered if needed.

The primary focus usually shifts towards:

daily broad-spectrum sunscreen
hats and protective clothing
avoiding excessive heat where practical
gentle skincare that supports the skin barrier.

If treatment is being considered during pregnancy or breastfeeding, it is important to seek advice from your GP, dermatologist or obstetric healthcare provider.

Why Sunscreen Is Essential Every Day

For melasma, sunscreen is not simply about preventing sunburn.

It helps reduce the ongoing stimulation that keeps melanocytes active.

Broad-spectrum SPF 50+ sunscreen protects against both UVA and UVB radiation.

Some evidence also suggests that visible light, particularly high-energy blue light, may contribute to melasma in susceptible individuals.

For people with established melasma, tinted sunscreens containing iron oxides may provide additional protection against visible light compared with untinted sunscreens alone.

Daily application, generous amounts and regular reapplication remain the foundation of long-term management.

Building a Daily Melasma Routine

A simple, consistent routine is often more effective than frequently changing products.

A typical routine may include:

Morning

Glow cleanser
Antioxidant Hydromist
pigment-supporting serum
Moisturiser if required
Broad-spectrum SPF 50+ sunscreen (preferably tinted if appropriate)

Evening

Gentle cleanser
Pigment-supporting treatment serum
Moisturiser
Retinoid on suitable nights if recommended

Progress is usually measured over months rather than weeks.

Reducing new pigment production is just as important as gradually fading existing pigmentation.

Why It Matters

Melasma is often frustrating because improvement can be slow and recurrence is common. However, understanding the condition changes expectations.

Rather than searching for a quick fix, successful management focuses on reducing the biological signals that repeatedly activate melanocytes. Daily sun protection, evidence-informed skincare and patience work together to gradually improve the appearance of pigmentation while helping maintain results over time.

Skin Therapist Tip

Many people judge their progress by how quickly existing patches fade.

An equally important sign of success is seeing fewer new areas of pigmentation develop. Preventing ongoing pigment formation often indicates that your routine is working, even before older pigmentation has noticeably lightened.

Joanne's Insight

One of the biggest misconceptions I hear is that melasma can simply be "removed."

In reality, melasma behaves more like a condition that needs ongoing management than a stain that can be erased. The people who achieve the most consistent results are usually those who combine realistic expectations with a gentle, consistent routine and daily sun protection.

I encourage clients to think about protecting their progress every day rather than chasing increasingly aggressive treatments. Healthy, resilient skin almost always responds better over the long term.

Continue Your Learning

To build on your understanding of melasma, explore these Academy lessons:

Understanding Pigmentation
How UV Radiation Affects the Skin
Understanding the Skin Barrier
Vitamin C in Skincare
Niacinamide Explained
Retinoids Explained
Chemical Exfoliation Explained
How Long Skincare Takes to Work
Building an Effective Skincare Routine

Key Takeaways

Melasma is a chronic pigmentary disorder caused by multiple interacting biological processes.
Hormones, UV radiation, visible light, heat and genetics all influence melanocyte activity.
Epidermal melasma generally responds more readily than dermal or mixed melasma.
Daily broad-spectrum sunscreen is one of the most effective long-term management strategies.
Tinted sunscreens containing iron oxides may provide additional protection against visible light.
Evidence-informed ingredients such as niacinamide, azelaic acid, tranexamic acid, vitamin C, cysteamine and retinoids may support improvement over time.
Hydroquinone remains an effective medical treatment but should only be used under appropriate medical supervision.
Consistency, patience and long-term maintenance are essential because melasma commonly recurs.

Conclusion

Melasma reflects the remarkable sensitivity of the skin's pigment-producing system. Rather than being caused by a single trigger, it develops through the interaction of hormones, sunlight, genetics, inflammation and the skin's own protective responses.

Although there is currently no permanent cure, advances in our understanding of melasma have led to more effective long-term management strategies than ever before. By combining thoughtful skincare, daily sun protection and realistic expectations, many people can achieve gradual, meaningful improvements while reducing the likelihood of future flare-ups.

Understanding the biology behind melasma is the first step towards making informed decisions that support healthier, more even-looking skin for years to come.