Hyper-pigmentation is the term used to describe a group of pigmentation issues caused by too much of a pigment called melanin being produced and deposited in our skin.

Dark spots can be very difficult to address with skincare and many people end up feeling like they’ve tried it all with nothing to show for it. If that’s you, then keep reading. We think we can change how you approach hyper-pigmentation.

The Pigment Pathway

In order to successfully address hyper-pigmentation, we have to understand why it occurs and how it happens.

Melanin is a dark brown pigment that’s one of the factors to give our skin, eyes, and hair its color. It’s produced within cells called melanocytes and while we all have the same number of these cells, the amount of melanin produced can vary. The melanocytes in light skin are less active and less productive than the melanocytes in dark skin. Melanin can help protect our skin against the damaging effects of the sun, although it doesn’t offer enough photoprotection to replace sunscreen. 

Sometimes, too much melanin is deposited in one area of the skin. This is what we refer to as hyper-pigmentation and addressing this requires breaking up melanin and preventing the overproduction of pigment. Because this is a multi-step process, understanding it can help us better adapt our routines.

The easiest way to explain the pigment pathway is to follow the life cycle of melanin as it’s produced and then ends up as part of a dark spot.

• The Signal. Environmental and internal triggers like sun exposure, inflammation, oxidative stress, trauma, or hormones signal our skin to create more melanin to protect itself. 
• Activation. In response to the signal, the enzyme tyrosinase is activated. This copper-containing enzyme controls and regulates melanogenesis (melanin production) within skin cells called melanocytes
• Melanogenesis (melanin production) occurs inside the melanosomes in the bottom layer of the epidermis. These organelles within the melanocytes are what synthesize, store, and transport melanin. 
• Melanosome Transfer. Once the melanosomes fill up with pigment, they’re sent off to where they’re needed. They’re transferred to skin cells called keratinocytes in the upper epidermis and this is when dark spots start to become visible. 
• DNA Protection. When our skin is exposed to UV radiation or anything else that can damage our skin, little enzymes degrade the melanosomes to release the melanin so it can form a “cap” around the cell’s DNA. Like a helmet, this protects the DNA from further damage.
• Shedding. Because melanin ends up in the keratinocytes, it ends its life cycle by being shed like any skin cell. The keratinocyte becomes a corneocyte and enzymes break down the “glue” holding the cells together so they can slough off in a process called desquamation.

If you’re not a science nerd, this explanation probably sounds like a lot. We love analogies here though and we’ve got a great one to help you visualize this process:

Let’s think of our melanocytes as a FedEx packing and shipping center. This time of year, employees (tyrosinase enzymes) are busy overseeing the process of production and shipping. Once they get an order, they fill up boxes (melanosomes) with the product (melanin). Once they’re packed full and ready to be shipped out, the boxes are shipped from the basal layer of the epidermis up to our customers (keratinocytes). These customers then open up their order to find the helmets (melanin) they ordered for outdoor activities. They use them until they’re worn out and they’re then discarded.

Types and Causes of Hyper-Pigmentation

Hyper-pigmentation is used to describe a variety of different types of dark spots that can pop up in our skin. Each form will have its own presentation and cause - and some are harder to clear up than others. We’ve listed the most common types here but you’ll need to see a provider for a diagnosis.

Post-Inflammatory Hyperpigmentation (PIH)

Looks like: small, brown or purple spots

Caused by: acne or other trauma to the skin

Not to be confused with post inflammatory erythema (PIE) or actual acne scars. PIE describes red spots and won’t respond to pigment inhibitors. And while PIH and PIE are often confused for acne scars, a true scar will be either raised or indented.

Solar Lentinges (Sun Spots)

Looks like: brown spots and patches, often accompanied by other signs of sun damage like wrinkles and coarse skin

Caused by: sun exposure and oxidative stress

Melasma

Looks like: gray or brown patches with uneven borders

Caused by: hormones but can be worsened by triggers like heat and sun exposure   

Epidermal melasma tends to be brown with defined borders and is more responsive to treatment. Dermal melasma has softer borders, is more gray to blue, and doesn’t respond well to most topicals.

The biggest mistake people make with hyper-pigmentation is only adding a tyrosine-inhibitor (think arbutin, kojic acid), neglecting the other steps of the pigment pathway.

Addressing Dark Spots

Understanding the entire process of hyper-pigmentation allows us to take a multi-pronged approach and stop it at every turn. This starts with looking at the cause and how we can prevent “the signal” from getting to the melanocytes - and ends with how we can more evenly distribute melanin and get it to shed faster once it reaches our keratinocytes.

Avoiding Triggers

Prevention will always be more effective than trying to fix a problem that’s already happened. That’s sometimes easier said than done though when there are many potential factors that can signal melanocytes to produce more pigment. Here’s some of the main ways we can prevent this.

• Sun protection (a non-negotiable for pigmentation issues)
• Iron oxides and UV filters that protect against the blue light portion of solar radiation for deeper skin tones
• Antioxidants 
• Anti-inflammatory agents
• Growth factors for wound healing
• Heat avoidance (primarily a trigger for melasma, individual triggers can vary so discuss with your provider)

Disrupting Pigment Formation

There are a number of methods to prevent the production of more melanin. No matter which one you choose, make sure it’s well researched and used at a concentration shown to be effective.

• Retinoids. Downregulate tyrosinase and compact stratum corneum for better penetration of pigment inhibitors.
• Tyrosinase inhibitors like azelaic acid, kojic acid, and arbutin. Hydroquinone is a “gold standard therapy” and also destroys the melanocytes so they can’t produce more melanin later.

Stopping Pigment Transfer 

Pigment inhibitors are great at stopping more melanin from being produced but what about the melanosomes that are already packed full of melanin and being sent out to the keratinocytes? Niacinamide is the only skincare ingredient shown to also prevent melanosome transfer, making it a great add-on. 

Bonus: niacinamide helps the skin better tolerate retinoids too.

Accelerating Pigment Removal

While prevention and pigment inhibitors are well studied, it can take months to see results. We have to stop new melanin production and also wait for all that excess pigment to be shed from the top layers of the skin. We can speed things along by using products that encourage dead skin cells to shed.

• Retinoids help better distribute pigment in the skin and also speed up cell turnover to clear hyper-pigmentation faster.
• Exfoliants like alpha hydroxy acids can work well with pigment inhibitors as they thin the stratum corneum and help exfoliate the melanin-carrying keratinocytes.

What to Remember

Our skin is a complex organ and hyper-pigmentation is actually a protective response by the skin in response to damage. It’s easy to be hard on ourselves and our skin, especially if we fall into the trap of comparing ourselves to filtered skin we see on Instagram. Sometimes it helps to not think of hyper-pigmentation as a flaw but as evidence of all the ways that our skin protects us.

The most effective hyper-pigmentation routine is the one that works for our skin while addressing the different steps in the process of pigment production. Still, results will take time and consistency. And if it’s been months without progress, seeing a dermatologist can be a good idea. 

References

https://onlinelibrary.wiley.com/doi/full/10.1111/pcmr.12986

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4964517/

https://www.hindawi.com/journals/omcl/2022/7881717/

https://www.sinclairdermatology.com.au/wp-content/uploads/2013/10/Pigmentation.pdf

https://www.merckmanuals.com/professional/dermatologic-disorders/pigmentation-disorders/hyperpigmentation

 

Mira is a skincare educator, blogger, and the content creator behind Skin Science by Mira and The Skincare Forum on Facebook. While skincare keeps her busy, she’s also pursuing her degree in Nursing and loves to spend her free time hiking.  As a content writer for Stratia Skin, Mira shares her evidence-based approach to skincare topics and a passion for making science accessible.