What Causes Melasma? Understanding Your Triggers

Melasma is not caused by one single thing. It is the result of several triggers working together – some you can control, and some you cannot.

Understanding what is driving your melasma is one of the most important steps in managing it well.

Hormones

Hormones are one of the biggest drivers of melasma, which is why it affects women so much more than men.

Oestrogen and progesterone both stimulate melanocyte activity- the cells in your skin that produce pigment. When hormone levels rise, as they do during pregnancy, while on the contraceptive pill, or during perimenopause, those melanocytes can go into overdrive.

This is why melasma is sometimes called the mask of pregnancy. Many women notice it appearing for the first time during pregnancy, then fading after they give birth. But for others, once it is triggered, it stays.

Hormones don’t cause melasma on their own. But in skin that is genetically susceptible, they can be the trigger that sets it off.

UV and Light

Sun exposure is the most significant external trigger for melasma. UV light directly stimulates melanin production. Even small amounts of exposure can cause pigment to darken or return after treatment.

But it is not just UV light. Heat plays a significant role too and that is where a lot of people get caught out.

Heat

Heat is one of the most underestimated melasma triggers. When your skin heats up, inflammation increases and melanocyte activity follows.

This includes more than just sun exposure. Hot baths and showers, saunas, HIIT training, and anything that raises your core temperature for a sustained period can all contribute to flares.

Many of our clients are surprised to learn that their melasma is worsening not from sun exposure, but from their morning shower or weekly sauna session. Small habit changes here can make a significant difference to your results.

Genetics

Between 55 and 65 percent of people with melasma have a family history of the condition. If your mother or sister has it, your risk is significantly higher.

Genetics determine how sensitive your melanocytes are to triggers like hormones, UV, and heat. You cannot change your genetics. But knowing your predisposition means you can be proactive before melasma becomes established or difficult to shift.

So What Does This Mean for You?

Most of our clients have a combination of two or three triggers working at the same time. Hormones plus sun, or genetics plus heat, for example.

Effective melasma management looks at the whole picture. In clinic, we work to reduce the pigment that is already there. But we also work with you to identify and minimise the triggers that keep bringing it back.

The more you understand your skin, the better equipped you are to protect it.

What’s Next?

In our next blog, we share our top 6 practical tips for managing melasma day to day – including some you have probably never heard before.