The ESK blog
What Causes Pigmentation? The Main Triggers Explained
23 October 2026
Tags
Written by Dr. Ginni Mansberg
If you've ever stood in front of the mirror wondering where a new dark patch came from, you're not alone! Pigmentation is one of the most common things patients ask me about, and also one of the most misunderstood. Most people assume it's purely a sun thing. It isn't. Sun exposure is the biggest single driver, but hormones, acne, inflammation, injury, certain medications and your genetics can all set the same process in motion.
The good news is that underneath all of that variety sits one shared mechanism. Once you understand it, the rest of this article (and the specific trigger behind your own pigmentation) makes a lot more sense. Below, I'll walk through each major cause, what the evidence actually shows, and where you can go for a deeper dive on the ones most relevant to you.
A Quick Recap: What Is Pigmentation?
Your skin colour comes from melanin, a pigment produced by cells called melanocytes that sit in the deepest layer of your epidermis. Under normal circumstances, melanocytes produce melanin fairly evenly, which is what gives you your baseline skin tone.
Pigmentation - or hyperpigmentation, to use the clinical term, happens when melanocytes are triggered to overproduce melanin in specific areas, creating patches, spots or a generally uneven tone. Whatever sets that trigger off, the visible result is the same: an excess of melanin sitting in the skin.
How Does Pigmentation Actually Form?
Every cause discussed below works through some version of the same pathway: something stimulates melanocytes, they ramp up melanin production, and that melanin gets deposited either in the epidermis (the surface layer) or the dermis (deeper down).
This depth matters more than most people realise. Epidermal pigmentation tends to respond well to topical treatment and time, because it's sitting close enough to the surface to be reached by active ingredients and to shed with normal skin turnover. Dermal pigmentation is stickier. It sits below the reach of most topicals, which is why some pigmentation seems to laugh in the face of your serum routine no matter how consistent you are.
The trigger varies. The outcome- your excess melanin doesn't. Which means figuring out your specific trigger is genuinely one of the most useful things you can do, because it determines both how preventable it is and what's likely to help.
UV Exposure: The Most Common Trigger
How UV Radiation Triggers Pigmentation
UV radiation is the single biggest driver of pigmentation, and it works quite directly: UV stimulates melanocytes to produce more melanin as a protective response, essentially your skin's attempt to shield itself from further damage. This is why existing pigmentation darkens with sun exposure, and why new spots tend to appear in habitually sun-exposed areas like the backs of hands, the cheeks, the décolletage.
Visible Light and Pigmentation
Here's the part that surprises most people: UV isn't the only part of sunlight that matters. Visible light, the light we can actually see makes up close to half of solar radiation, and there's now a reasonable body of evidence that it also contributes to pigmentation, particularly in medium-to-deeper skin tones.
Blue Light and Pigmentation
Within visible light, the blue-violet end of the spectrum (high-energy visible or "HEV" light) has drawn the most research interest. In Fitzpatrick skin phototypes III and above (darker skin), this blue-violet light appears to be a meaningful contributor to longer-lasting hyperpigmentation, with melanocytes able to detect it via specific “photoreceptors” that switch on melanin production.
It’s worth noting that most of this research is about outdoor light exposure, not phone or laptop screens. The amount of blue light your skin picks up from a screen is a tiny fraction (somewhere in the order of 100 to 1000 times weaker than what you get from the sun), so "doomscrolling causes pigmentation" isn't really an evidence-based concern. Sunlight is still where the exposure that matters actually comes from.
The practical upshot is that a standard UV-only sunscreen may not be doing the full job, particularly if you already have pigmentation or a medium-to-deep skin tone. This is part of why there is growing interest in broad-spectrum, visible-light-inclusive protection. That means including iron oxide in the formulation.
Why Pigmentation Worsens Without Sunscreen
Whatever originally caused your pigmentation, unprotected sun exposure keeps the melanin-production pathway switched on. That's the frustrating catch. You can be doing everything right with actives and still watch progress stall or reverse if sunscreen isn't part of the daily routine. Consistent, broad-spectrum protection is genuinely the single most important step regardless of what triggered your pigmentation in the first place.
Hormonal Causes of Pigmentation
Oestrogen and progesterone can stimulate melanocytes directly, which is why hormonal pigmentation has a pattern all its own. It tends to show up as melasma, usually across the cheeks, forehead, upper lip or jawline.
Pregnancy
Hormonal shifts in pregnancy commonly trigger melasma, sometimes called the "mask of pregnancy." It's extremely common, and for many women it fades, though not always completely after birth. If you're pregnant and noticing new pigmentation, it's worth reading our dedicated articles on why melasma happens in pregnancy and whether it's safe to treat while pregnant, since treatment options are more limited during this window.
→ For a full deep dive: [Why does melasma happen in pregnancy?]
Menopause
This is one I get asked about constantly, and it makes sense. Patients often describe sunspots "appearing out of nowhere" in their late 40s and 50s. Menopause with its declining oestrogen levels is not directly responsible for pigmentation. However, losing oestrogen rapidly accelerates skin ageing and skin barrier impairment, which can accelerate the appearance of any age and sun-related pigmentation. In fact 90% of women will have at least one solar lentigine or sunspot after the age of 50. We've covered this in more depth in our articles on why pigmentation suddenly appears in menopause and where those sunspots have actually come from.
→ For a full deep dive: [Why does pigmentation suddenly appear in menopause?]
Acne and Pigmentation
Why Acne Leaves Dark Marks
The dark marks left behind after a breakout are known as post-inflammatory hyperpigmentation, or PIH. The inflammation involved in acne, even a single spot, stimulates melanocytes in that area, leaving a flat mark once the breakout itself has resolved. It's worth distinguishing this from acne scarring: PIH is a colour change, not a textural one, which matters because they're treated quite differently.
Picking or squeezing a breakout increases local inflammation and, in turn, tends to make any resulting mark darker and slower to fade.
Can Acne Cause Permanent Pigmentation?
Most post-acne marks do fade with time, though how long that takes varies. Skin tone, how deep the original inflammation went, and ongoing sun exposure all play a role. In darker skin tones in particular, PIH can persist for months. It's not usually permanent, but it can certainly outlast the acne itself by a long way, which is often the more frustrating part.
Preventing Post-Acne Pigmentation
Treating breakouts early and gently, resisting the urge to pick, and wearing sunscreen daily (sun exposure darkens existing PIH) are the three most useful habits here. If you want product-specific guidance, our article on effective solutions to hyperpigmentation caused by breakouts goes into more detail.
→ For a full deep dive: [Effective Solutions To Hyperpigmentation Caused By Breakouts]
Inflammation and Skin Barrier Damage
Acne isn't the only inflammatory trigger. In reality, any inflammation can switch on the same PIH pathway.
Pigmentation After Eczema
Eczema flares can leave both darker marks (post-inflammatory hyperpigmentation) and, in some cases, lighter patches (post-inflammatory hypopigmentation), depending on the individual and the severity of the flare. Managing flares promptly is the most effective way to limit this.
Skin Barrier Damage and Pigmentation
A compromised skin barrier is more reactive and prone to low-grade inflammation, which can in turn drive pigmentation. It’s an under-appreciated side effect of over-cleansing, over-exfoliating, or introducing too many active ingredients too quickly. Supporting barrier function isn't just a comfort measure; it's genuinely a pigmentation-prevention strategy.
Skin Injury and Cosmetic Procedures
Pigmentation After Skin Injury
Cuts, burns, insect bites and even friction can all trigger PIH at the site of injury as part of the skin's normal healing and inflammatory response. Darker skin tones tend to be more prone to this, sometimes markedly so.
Pigmentation After Cosmetic Procedures
This is the one that surprises people; treatments intended to improve the skin, like lasers and peels, can paradoxically trigger pigmentation if they're too aggressive for the individual's skin type, or performed without adequate aftercare. This is why using a skincare first approach is recommended by dermatologists.
How to Prevent Treatment-Induced Pigmentation
Choosing a practitioner experienced with your specific skin type, appropriate pre- and post-procedure sun protection, and following aftercare instructions properly all meaningfully reduce this risk. If you're considering a procedure and have a history of pigmentation, it's worth raising this directly before booking in. Most recommend using a tyrosinase inhibitor like our Enlighten Gold before and after a procedure.
Medications and Drug-Induced Pigmentation
A lesser known but genuinely important cause: certain medications, including some antibiotics, anti-inflammatory drugs, hormonal treatments and chemotherapy agents can cause or worsen pigmentation as a side effect. It can look different from sun- or inflammation-driven pigmentation, sometimes appearing in unusual locations or with a different colour quality.
If you suspect a medication might be contributing to pigmentation you're seeing, the right move is to raise it with your prescribing doctor rather than stopping the medication yourself. There's often a reason it's necessary, and there may be alternatives or protective steps that don't require coming off it.
Genetics
Not everyone exposed to the same trigger develops the same degree of pigmentation, and genetics is a large part of why. Skin tone and Fitzpatrick type influence how reactive your melanocytes are to begin with, and melasma in particular has a recognised tendency to run in families.
You can't change your genetic starting point. What you can change is how well you manage the triggers layered on top of it.
The Common Thread & And What You Can Do
Every cause above ultimately funnels through the same mechanism, and nearly all of them are amplified by UV and visible light exposure. That's why daily, broad-spectrum sun protection is the one universal step that helps regardless of what originally triggered your pigmentation.
Zinc Shade is a lightweight matte day cream and primer. Its non-greasy, matte finish allows for smooth application and works well under makeup. We spent countless iterations perfecting this lightweight, non-greasy formula to avoid the typical white cast and thick feel of zinc products. The results? A matte finish that works beautifully under makeup. With well tolerated matte finish, it's also well suited to irritable and blemish and bump prone skin. With SPF 15 it also provides broad-spectrum sun protection against UVA and UVB rays. Key features: Lightweight, matte formula suitable for daily use Smooth application with minimal white cast Broad-spectrum UV protection Tested SPF 15 with enhanced UVA coverage Usage: Apply evenly to all exposed areas of skin before sun exposure. Reapply as needed throughout the day.
Zinc Shade
Tyrosinase inhibitors are key skincare ingredients for managing pigmentation. Tyrosinase is an enzyme involved in several stages of melanin production and because these pathways are central to pigment formation, blocking tyrosinase can reduce the skin’s ability to produce excess pigment. That’s why tyrosinase inhibitors are so important when we talk about treating and preventing pigmentation.
Common tyrosinase inhibitors include hydroquinone, arbutin and kojic acid, but 4-n-butylresorcinol seems to be the strongest non-prescription option, despite being non irritating. This resorcinol derivative is one of the most potent tyrosinase inhibitors available without a prescription. In laboratory comparisons, it inhibits tyrosinase more strongly than hydroquinone, kojic acid or arbutin. It also targets another enzyme involved in melanin production, TRP-1.
As a result, 4NB has been reported to be 24 times more effective than kojic acid and more than 300 times more effective than arbutin.
Clinical studies also show measurable improvement in pigmentation and melasma from as early as eight weeks, with continued gains over several months. Importantly, it appears to do this with a better safety and tolerability profile than hydroquinone.
Research has also shown 4-n-butylresorcinol to be effective for melasma, post-inflammatory hyperpigmentation and solar lentigines.
Meet your new secret weapon against uneven skin tone. Enlighten Gold is a lightweight moisturiser designed to help reduce the appearance of pigmentation. We've blended high strength 4nB (a gentle, and highly effective pigmentation fighter) with PHAs (think of them as a soft exfoliant that plays nice with sensitive skin) and niacinamide to support your skin’s barrier to effectively improve your skin. Whether your skin is oily, dry, or somewhere in between, this pigmentation moisturiser fits right in. Why you'll love it: For best results, use Enlighten Gold in the morning and Ultimate A Gold at night (available together in our Golden Duo). This AM/PM approach targets pigmentation while supporting long-term skin change.
Enlighten Gold
Alongside preventing new pigment from forming, it’s important to treat pigmentation that is already present. Active vitamin A, known as retinoic acid, communicates directly with skin cells, encouraging more efficient turnover, supporting collagen production and reducing the activity of collagen‑breaking enzymes.
Retinal, or retinaldehyde, is a vitamin A derivative and one of the most effective over-the-counter actives for pigmentation. It mainly works by speeding up cell turnover, helping pigmented cells move to the surface and shed sooner so dark spots fade more quickly. Over time, vitamin A derivatives may also help normalise melanocyte behaviour.
Of the non-prescription retinoids, retinal is closest to prescription-strength retinoic acid: it is only one conversion step away, compared with two for retinol. This usually means faster results with similar tolerability when introduced gradually. Start two to three nights a week, then build up as your skin adjusts.
The game-changing night cream developed in partnership with Selma Blair - combines our most potent hero ingredients to effectively and gently tackle the most common skin concerns – in one product. Tackling the signs of aging skin including fine lines, skin elasticity, impaired barrier function, hydration, dullness and uneven skin tone. it is our most powerful product yet and yet it’s still ridiculously well tolerated. Wake up to skin that's supple, smoother, and softer. For the most irritable of skin, Ultimate A may be a better option, particularly when starting to use Retinal based products
Ultimate A Gold
Ultimate A Gold: the most effective and gentle ingredients that evidence based cosmeceutical skincare has to offer, in one revolutionary formula.
*Ultimate A Gold (Retinal) may transfer onto white or light-coloured fabrics. For best results, we recommend using darker clothing or surfaces to avoid visible marks.
There are some other skincare ingredients that make a genuine difference: supporting your skin barrier so you're not adding unnecessary inflammation into the mix is a terrific option and one of the best is Vitamin B3 AKA niacinamide. That’s because apart from being an antioxidant, niacinamide also helps prevent the transfer of pigment from the pigment producing “melanocytes” to the rest of your skin cells.
Shop ESK Niacinamide Collection
Repair + is a moisturiser formulated to support skin hydration and barrier function. Its combination of niacinamide, panthenol, hyaluronic acid, and ceramides is designed to help maintain skin moisture, strengthen the barrier function of the skin, reduce the appearance of redness, and support overall skin texture. Key Features:
Repair +
And finally, Vitamin C is another great antioxidant with great brightening support. Though not a “first line” skincare ingredient, it’s an excellent add on!
C Forte Morning Serum is packed with 16% L-ascorbic acid, the purest form of Vitamin C, combined with vitamin E and ferulic acid for maximum results. Vitamin C (Ascorbic Acid) is an anti-oxidant helping neutralise free radicals (associated with exposure to the sun). The result? A brighter, firmer, plumper looking skin with fewer fine lines apparent and a more even skin tone. Formulated at the ideal pH (2.5-3.5) and housed in airless, opaque packaging, C Forte ensures stability and effectiveness, delivering radiant skin with every use.
C Forte
Featuring;
- Evidence based ingredients and formulations for superior efficacy.
- Potent skin brightening ingredients
- A plumper, more hydrated and even toned skin.
Note: C Forte can exacerbate acne and may be too strong for irritable skin.
If you're not sure what's behind your own pigmentation, that's worth a conversation with a doctor or dermatologist rather than guessing. The right approach differs quite a bit depending on whether you're dealing with hormonal melasma, sun-driven pigmentation, or post-inflammatory marks.
Key Takeaways
- Pigmentation always comes down to the same mechanism: an overproduction of melanin.
- UV exposure is the most common trigger, and also the biggest amplifier of every other cause on this list.
- Hormones, acne, inflammation, injury, cosmetic procedures, medications and genetics can all switch on the same pathway.
- Identifying your likely trigger is the key to choosing the right prevention and treatment approach.
- Daily sun protection remains the single most effective step you can take, no matter what caused your pigmentation in the first place.
References
[1] Guermazi, D.; Saliba, E. The Genetics and Evolution of Human Pigmentation. Biology 2025, 14, 1026. https://doi.org/10.3390/biology14081026
[2] Thawabteh AM, Jibreen A, Karaman D, Thawabteh A, Karaman R. Skin Pigmentation Types, Causes and Treatment-A Review. Molecules. 2023 Jun 18;28(12):4839. doi: 10.3390/molecules28124839. PMID: 37375394; PMCID: PMC10304091.
[3] Schlessinger DI, Rahimi N, Schlessinger J. Biochemistry, Melanin. [Updated 2025 Jul 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459156/
[4] Miao F, Wan J, Zhou Y, Shi Y. Unraveling Melasma: From Epidermal Pigmentation to Microenvironmental Dysregulation. Biology (Basel). 2025 Oct 13;14(10):1402. doi: 10.3390/biology14101402. PMID: 41154805; PMCID: PMC12561912.
[5] Yardman-Frank JM, Fisher DE. Skin pigmentation and its control: From ultraviolet radiation to stem cells. Exp Dermatol. 2021 Apr;30(4):560-571. doi: 10.1111/exd.14260. Epub 2020 Dec 24. PMID: 33320376; PMCID: PMC8218595.
[6] He X, Jin S, Dai X, Chen L, Xiang L, Zhang C. The Emerging Role of Visible Light in Melanocyte Biology and Skin Pigmentary Disorders: Friend or Foe? J Clin Med. 2023 Dec 4;12(23):7488. doi: 10.3390/jcm12237488. PMID: 38068540; PMCID: PMC10707362.
[7] Haghani M, Abbasi S, Abdoli L, Shams SF, Baha'addini Baigy Zarandi BF, Shokrpour N, Jahromizadeh A, Mortazavi SA, Mortazavi SMJ. Blue Light and Digital Screens Revisited: A New Look at Blue Light from the Vision Quality, Circadian Rhythm and Cognitive Functions Perspective. J Biomed Phys Eng. 2024 Jun 1;14(3):213-228. doi: 10.31661/jbpe.v0i0.2106-1355. PMID: 39027713; PMCID: PMC11252550.
[8] Ferreira, L., Torres, B., Hameed, H., Vieira, A. C. F., Singh, S. K., Dua, K., Gomez Veiga, F., Pires, P. C., Mazzola, P. G., & Paiva-Santos, A. C. (2024). Updated insights of active cosmetic ingredients against blue light: In vivo and in vitro evidence. Journal of Drug Delivery Science and Technology, 101, 106306. https://doi.org/10.1016/j.jddst.2024.106306
[9] Fatima S, Braunberger T, Mohammad TF, Kohli I, Hamzavi IH. The Role of Sunscreen in Melasma and Postinflammatory Hyperpigmentation. Indian J Dermatol. 2020 Jan-Feb;65(1):5-10. doi: 10.4103/ijd.IJD_295_18. PMID: 32029932; PMCID: PMC6986132.
[10] Betti Merdiani Putri, and Metti Herliani Putri. 2026. “A Comprehensive Systematic Review of The Relationship Between Sunscreen Use and Prevention of Photoaging”. The International Journal of Medical Science and Health Research 29 (1): 1-52. https://doi.org/10.70070/dmhdf292.
[11] Böhm M. Hormone und Hautpigmentierung – Grundlagen und klinische Relevanz [Hormones and skin pigmentation: fundamentals and clinical relevance]. Dermatologie (Heidelb). 2026 Jan;77(1):9-17. German. doi: 10.1007/s00105-025-05636-4. Epub 2026 Jan 5. PMID: 41489668.
[12] Zhang, J.; Wang, T.; Li, Z.; Qin, C.; Dai, J.; Zhao, Y.; Wu, S.; Jia, Z. Hormonal Crosstalk in Melasma: Unraveling the Dual Roles of Estrogen and Progesterone in Melanogenesis. Int. J. Mol. Sci. 2025, 26, 10856. https://doi.org/10.3390/ijms262210856
[13] Gupta SN, Madke B, Ganjre S, Jawade S, Kondalkar A. Cutaneous Changes During Pregnancy: A Comprehensive Review. Cureus. 2024 Sep 23;16(9):e69986. doi: 10.7759/cureus.69986. PMID: 39445254; PMCID: PMC11497768.
[14] Bravo, B.; Penedo, L.; Carvalho, R.; Dal Vesco, C.; Calomeni, M.; Gapanowicz, D.; Kemen, E.; Paes, R.; Renke, G. Dermatological Changes during Menopause and HRT: What to Expect? Cosmetics 2024, 11, 9. https://doi.org/10.3390/cosmetics11010009
[15] Mardani G, Nasiri MJ, Namazi N, Farshchian M, Abdollahimajd F. Treatment of Solar Lentigines: A Systematic Review of Clinical Trials. J Cosmet Dermatol. 2025 Apr;24(4):e70133. doi: 10.1111/jocd.70133. PMID: 40145274; PMCID: PMC11948172.
[16] Auffret N, Leccia MT, Ballanger F, Claudel JP, Dahan S, Dréno B. Acne-induced Post-inflammatory Hyperpigmentation: From Grading to Treatment. Acta Derm Venereol. 2025 Apr 22;105:adv42925. doi: 10.2340/actadv.v105.42925. PMID: 40263971; PMCID: PMC12041799.
[17] Alamri, A., Alzahrani, D., Alharbi, G., Jan, R., Alsubaie, L. A., Alghamdi, A., … Jfri, A. (2025). The Predictive Factors of Acne Scarring and Post-Inflammatory Hyperpigmentation: A Retrospective Cohort Study. Clinical, Cosmetic and Investigational Dermatology, 18(0), 143–150. https://doi.org/10.2147/CCID.S504281
[18] Yadav G, Sauder M, Siddha S, Zeinab R, Barakat M, Joseph M. A Review of Post-Inflammatory Pigmentation Changes: Pathophysiology, Diagnosis and Treatment. J Cutan Med Surg. 2026 Mar 18:12034754261427395. doi: 10.1177/12034754261427395.
[19] Xin Nie, Sen Hou, Anzhang Li, Pigmented skin spots: Morphological characteristics, common causes, and treatment with cosmetic ingredients. Journal of Dermatologic Science and Cosmetic Technology, Volume 2, Issue 4, 2025. https://doi.org/10.1016/j.jdsct.2025.100125.
[20] Davis EC, Callender VD. Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. J Clin Aesthet Dermatol. 2010 Jul;3(7):20-31. PMID: 20725554; PMCID: PMC2921758.
[21] Camayo TV, Lee VR, Zhou XA. Drug-Induced Pigmentation. [Updated 2025 Dec 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542253/
[22] Guermazi D, Saliba E. The Genetics and Evolution of Human Pigmentation. Biology (Basel). 2025 Aug 10;14(8):1026. doi: 10.3390/biology14081026. PMID: 40906177; PMCID: PMC12383888.
[23] Somboon, K.; Chng, C.-P.; Huang, C.; Gupta, S. Enhancing Niacinamide Skin Penetration via Other Skin Brightening Agents: A Molecular Dynamics Simulation Study. Int. J. Mol. Sci. 2025, 26, 1555. https://doi.org/10.3390/ijms26041555
[24] Correia G, Magina S. Efficacy of topical vitamin C in melasma and photoaging: A systematic review. J Cosmet Dermatol. 2023; 22: 1938-1945. doi:10.1111/jocd.15748