Dark spots: what causes them and what really helps

Dark spots are localised patches of increased melanin production in the skin. They are primarily caused by UV exposure, hormonal changes and inflammation. In this guide, we explain the different types of pigmentation, which active ingredients have clinically proven efficacy, why daily SPF is the one essential step in your routine and when to see a dermatologist. At Dulcia, we developed Plus – First Aid for Dark Spots with eight active ingredients, and for sensitive skin we recommend azelaic acid, our second most-visited ingredient page.

What are dark spots?

Dark spots are defined areas of skin with a higher concentration of melanin, the pigment produced by melanocytes in the basal layer of the epidermis. They are not a single condition, but several distinct ones: solar lentigines (age spots), hormonally triggered melasma, post-inflammatory hyperpigmentation (PIH) after acne or injury, and, less commonly, drug-induced or traumatic pigmentation (Nicolaidou & Katsambas, Clin Dermatol, 2014).
Pigmentation is not a disease, but a normal biological mechanism through which the skin responds to UV radiation, inflammation and hormonal signals. Problems arise when melanin production is locally excessive or unevenly distributed. Knowing which type of pigmentation you are dealing with is key to choosing the right skincare.

What types of pigmentation are there?

The four most common types of pigmentation differ in cause, age of onset, location and prognosis: sun spots (lentigines solares) develop from cumulative UV exposure, melasma from hormonal changes, post-inflammatory hyperpigmentation (PIH) after acne or irritation, while seborrhoeic keratosis, a harmless tumour-like growth, is often mistaken for pigmentation.

Not pigmentation, but a benign tumour; managed by a dermatologist
According to an epidemiological review, 90% of melasma cases affect women, while 50 to 70% of predisposed pregnant women develop it during pregnancy as so-called “chloasma gravidarum” or the “mask of pregnancy” (Handel et al., An Bras Dermatol, 2014). PIH, by contrast, is most common in skin phototypes III to V, occurring in 65% of people after acne has cleared, compared with 15% in phototypes I to II (Kaufman et al., Am J Clin Dermatol, 2018). Solar lentigines affect more than 90% of the population over 60 (Cestari et al., An Bras Dermatol, 2014).
The takeaway: melasma and PIH require a different approach from solar lentigines. Seborrhoeic keratosis should be assessed by a dermatologist.

Why do dark spots develop?

Pigmentation develops as the skin's defensive response to harmful stimuli: UV radiation, hormonal signals (oestrogen, progesterone) and inflammatory cytokines.
The key enzyme is tyrosinase, which converts the amino acid tyrosine into melanin within melanocytes. Inhibiting tyrosinase and blocking melanosome transfer to keratinocytes are the two most effective routes to lightening pigmentation (Kim & Uyama, Cell Mol Life Sci, 2005). Melanocytes live in the basal layer of the epidermis and produce protective melanin after UV exposure. UV radiation not only stimulates tyrosinase, but also increases the number of melanocytes themselves. Long-term sun exposure results in solar lentigines.
Hormones work differently. Oestrogen and progesterone have receptors directly on melanocytes and, at elevated levels (pregnancy, hormonal contraception), activate the tyrosinase pathway independently of UV. This is why melasma also appears in women who protect themselves from the sun if they have a hormonal trigger.
Inflammation is the third mechanism. The cytokines IL-1α, TNF-α and endothelin-1 stimulate melanin synthesis as a defensive signal following damage (Thornfeldt, J Cosmet Dermatol, 2008). This means that any acne, eczema or injury in darker phototypes carries a risk of post-inflammatory hyperpigmentation. Managing rosacea or acne well, for example with salicylic acid or niacin, also helps prevent subsequent pigmentation.

Which active ingredients work on pigmentation?

Ingredients with clinically proven efficacy for pigmentation include niacinamide (2 to 5%), azelaic acid (10% in cosmetics, 15 to 20% on prescription), vitamin C and its stable derivatives, AHA acids (glycolic, lactic) and retinoids, including retinol and plant-based retinol-like extracts. Combining two to three mechanisms works better than a single treatment (Rendon & Gaviria, Dermatol Surg, 2005).

Niacinamide has been studied most extensively for PIH and melasma. A study by Hakozaki et al. (Br J Dermatol, 2002) involving 18 women using 2% niacinamide twice daily for 8 weeks demonstrated significant lightening of pigmentation by blocking melanosome transfer (35 to 68% inhibition in vitro). Navarrete-Solís et al. (2011) compared 4% niacinamide with 4% hydroquinone for melasma (n = 27, 8 weeks, split-face) and achieved a good to excellent response in 44% versus 55% for hydroquinone: comparable efficacy with better tolerability (adverse reactions 18% versus 29%). Bissett et al. (2005) documented a 6.8% reduction in hyperpigmentation measured by colourimetry after 12 weeks with 5% niacinamide (n = 50, p < 0.05).

Azelaic acid works in three ways at once: it competitively inhibits tyrosinase, has antimicrobial properties and reduces inflammation (Sieber & Hegel, Skin Pharmacol Physiol, 2014). Importantly, it is selectively cytotoxic only to hyperactive melanocytes, so it does not lighten healthy skin or cause paradoxical depigmentation (Schulte et al., J Drugs Dermatol, 2015). It is used at concentrations of around 10% in cosmetics and 15 to 20% in medicines. It is also safe during pregnancy. We discuss its mechanism and our experience in our azelaic acid ingredient entry.

Vitamin C inhibits tyrosinase and acts as an antioxidant. L-ascorbic acid is effective only at a pH below 3.5 and a concentration of at least 8%; otherwise, it degrades rapidly (Pullar et al., Nutrients, 2017). Stable derivatives (Ascorbyl Tetraisopalmitate, Sodium Ascorbyl Phosphate, Magnesium Ascorbyl Phosphate) address the stability issue. We cover niacinamide and retinol separately.

Hydroquinone, the gold standard for depigmentation for many years, has been banned in cosmetics in the EU since 2001 (Annex II to Regulation 1223/2009). In the USA, the FDA withdrew OTC forms in 2020; it remains available only on prescription. Today's cosmetic formulations prioritise a combination of plant-based and safe synthetic ingredients (Draelos et al., J Cosmet Dermatol, 2020).

Prevention is better than treatment: SPF as the number one strategy

Daily application of broad-spectrum SPF 30+ is the most effective preventive measure for all forms of hyperpigmentation. According to Desai (J Clin Aesthet Dermatol, 2014), melasma recurrence without sun protection exceeds 95% within two years; with consistent SPF use, it falls below 10%. Without SPF, even the best-dosed depigmenting treatment will fail.
UV radiation is the main trigger for melanogenesis: it stimulates tyrosinase, regenerates melanosomes and, with prolonged exposure, activates more melanocytes. In recent years, attention has also turned to HEV, or high-energy visible blue light from monitors, screens and the sun. HEV also stimulates pigmentation, although less strongly than UV.
For pigmentation and sensitive skin, mineral (physical) filters, zinc oxide and titanium dioxide, are recommended over chemical filters. Physical filters create a barrier that reflects UV rays, is not systemically absorbed and is biologically inert. The correct application amount is approximately half a teaspoon for the face (the two-finger rule); smaller amounts do not deliver the stated protection factor. When spending longer periods outdoors, reapply every 2 hours. Even on cloudy days, UVA passes through clouds and glass.
Our approach at Dulcia: our Protective Face Cream SPF 30 uses physical filters in micro form, is hypoallergenic, leaves no white cast and protects against UVA, UVB and blue light. For higher-risk situations (melasma, phototypes III to V, frequent time outdoors), we also offer SPF 50.

At Dulcia: how we developed Plus First Aid for Dark Spots

At Dulcia, we formulate with one principle: several mechanisms at once, 100% active ingredients, no fragrance or preservatives. When developing Plus – First Aid for Dark Spots (20 ml), we combined eight effective ingredients that act before, during and after melanin synthesis. The aim: to reduce existing pigmentation and prevent new pigmentation from developing.
When developing Plus Pigment, we deliberately chose not to rely on a single highly concentrated ingredient. We created a formula in which rainbow algae extract breaks down existing melanosomes, an AHA complex exfoliates the outermost layer of the skin and allows other ingredients to penetrate more deeply, and ferulic acid stabilises antioxidants and enhances their effects (Ghaisas et al., Int Wound J, 2014). According to Telang (Indian Dermatol Online J, 2013), combining vitamin C with vitamin E and ferulic acid increases photoprotection approximately eightfold compared with vitamin C alone.
The retinol-like sea fennel extract (Crithmum maritimum) is a CO₂ extract that acts similarly to retinoids, stimulates keratinocyte proliferation and evens out skin tone. Unlike retinol itself, it is not subject to the EU limit of 0.3% RE under SCCS/1639/21. Daisy targets age spots caused by cumulative UV exposure. Actibiom and red algae extract Jania Rubens support the skin's microbial balance and energy metabolism. Raykami adds protection against HEV blue light from screens.
The entire Plus range is free from preservatives, essential oils and fragrance. We chose 100% active ingredients: no water-based fillers, no carriers without a function. In our testing, customers most often report two things: gradual fading of spots after 4 to 6 weeks of targeted treatment and improved overall skin tone. We deliberately left azelaic acid out of Plus Pigment; you will find it in Plus – Soothing and Rosacea and Plus – First Aid for Acne. For pigmentation, we chose a multi-mechanism approach; for sensitive skin and PIH after acne, an azelaic acid approach.

Azelaic acid and niacinamide: two proven choices for sensitive skin

If you are looking for a gentler or sustainable long-term approach to lightening pigmentation, azelaic acid and niacinamide are the safest clinically proven choices. Both are also suitable during pregnancy and for sensitive skin. Azelaic acid is our second most-visited ingredient page, and you will find it in the Plus Akné and Plus Rosacea ranges.
Azelaic acid is a natural dicarboxylic acid with a well-documented profile: it competitively and reversibly inhibits tyrosinase, reduces inflammation by inhibiting the enzyme kallikrein KLK5, and has antimicrobial activity against Propionibacterium acnes and Staphylococcus epidermidis (Sieber & Hegel, 2014). Most importantly from a cosmetic perspective, it is selectively cytotoxic only to hyperactive melanocytes, so it does not affect healthy skin or cause paradoxical depigmentation (Schulte et al., 2015). Under the US classification, it is pregnancy category B and is considered safe.
Niacinamide (vitamin B3) works through a different mechanism: it inhibits melanosome transfer from melanocytes to keratinocytes. Even when melanin is produced, it does not reach the visible part of the epidermis (Hakozaki et al., 2002). At a concentration of 2 to 5%, twice daily for 8 to 12 weeks, it delivers reliable results for both melasma and PIH. It also strengthens the skin barrier and supports ceramide synthesis.
The two ingredients can be combined with each other, with vitamin C, with AHA acids (on alternate days) and with moisturising products. The old myth that “vitamin C and niacinamide cancel each other out” applied only to unstabilised laboratory mixtures at high temperatures; it is not supported in modern cosmetic formulations.

Vitamin C for pigmentation: why the form matters

Vitamin C is a powerful antioxidant and tyrosinase inhibitor, but L-ascorbic acid is unstable: it degrades with exposure to light, oxygen and heat. Stable derivatives such as Ascorbyl Tetraisopalmitate (ATIP), Sodium Ascorbyl Phosphate and Magnesium Ascorbyl Phosphate address the stability issue and allow formulation at a pH higher than the 3.5 threshold required for L-ascorbic acid.
L-ascorbic acid is the gold standard form of vitamin C in clinical studies, but it is also the least stable. To work, it must be present at a concentration of at least 8%, at a pH below 3.5 and in packaging that minimises contact with air (airless packaging, opaque glass, prompt use after opening). According to Pullar et al. (2017), degraded L-ascorbic acid at a high pH loses efficacy and may have a pro-oxidant effect.
Stable derivatives are esters that penetrate the skin's lipid barrier and are enzymatically hydrolysed there into active ascorbic acid. Ascorbyl Tetraisopalmitate (ATIP) is oil-soluble, suitable for oil-based and emulsion formulations, non-irritating and stable against oxidation.
Our approach at Dulcia: our Vitamin C Serum (20 ml) is based on Ascorbyl Tetraisopalmitate. We chose an oil-soluble form for stability and gentleness. The texture is light, absorbs quickly and is tolerated even by sensitive skin. In your morning routine, apply it before moisturiser and SPF.

What does not work (and may cause harm)

Home remedies such as lemon juice, bicarbonate of soda, vinegar or harsh physical scrubs can worsen pigmentation rather than lighten it. Lemon juice contains furanocoumarins, which cause phytophotodermatitis after UV exposure. Bicarbonate of soda disrupts the skin's pH barrier. Vinegar at concentrations commonly recommended in home remedies damages the skin microbiome.
Lemon juice. Lemons and limes contain psoralens and bergapten, plant compounds that become phototoxic after application to the skin followed by UV exposure. The reaction is called phytophotodermatitis and can result in blisters, burns and long-lasting pigmentation that may persist for months or years. In medical literature, the condition is sometimes recorded as “Margarita photodermatitis”, as it typically appears after contact with lime juice at a bar. So lemon does not remove pigmentation; combined with sunlight, it causes it.
Bicarbonate of soda. Skin has a pH of 4.7 to 5.5 (slightly acidic). Bicarbonate of soda has a pH of around 9 (alkaline). Applying it shifts the skin's pH by more than 4 units, disrupts the acid mantle, weakens the barrier and causes inflammation. According to Thornfeldt (2008), inflammation is a direct trigger for melanogenesis. Bicarbonate of soda therefore paradoxically encourages post-inflammatory hyperpigmentation.
Vinegar, physical scrubs, over-exfoliation. Vinegar has a pH of around 2.4, but without buffering it is harsh; the 1:1 ratio suggested in home remedies can cause chemical burns. Physical scrubs (grains, scrubbing, brushes) mechanically damage delicate skin and trigger inflammation. Chronic over-exfoliation leads to barrier dysfunction, triggering compensatory inflammation and further pigmentation. With pigmentation, less is more and consistency is key.

When should you see a dermatologist? The ABCDE rule

Not every dark spot is harmless pigmentation. If you notice suspicious signs (asymmetry, an irregular border, multiple colours, a diameter over 6 mm or changes over time), see a dermatologist immediately. This is the American Academy of Dermatology's ABCDE rule for early melanoma screening, the most dangerous form of skin cancer (Rigel et al., Arch Dermatol, 2005).
• A: Asymmetry – one half of the spot does not look like the other.
• B: Border – an irregular, jagged or blurred edge.
• C: Colour – several shades of black, brown, red, white or blue within one lesion.
• D: Diameter – over 6 mm, approximately the size of a pencil rubber.
• E: Evolution – a visible change in size, shape or colour, or bleeding or itching over weeks to months.
The ABCDE rule has a sensitivity of 57 to 90% and a specificity of 59 to 90% in population screening. Adding “E” (evolution) increased sensitivity by approximately 15% compared with the original ABCD rule (Rigel et al., 2005). An additional indicator is the “ugly duckling sign”: a spot that looks different from others on the body is suspicious even without other ABCDE criteria.
There are also reasons for a dermatological examination beyond ABCDE: a new spot after the age of 50, a bleeding, itchy or painful lesion, pigmentation that does not respond after 3 to 6 months of consistent cosmetic skincare, melasma resistant to cosmetic treatment (a dermatologist may prescribe tranexamic acid, prescription azelaic acid at 15 to 20%, or chemical peels), suspected actinic keratosis (rough, scaly patches in people over 50, a precancerous condition) and suspected seborrhoeic keratosis (a benign raised growth). If in any doubt, seek advice.

A daily routine for pigmentation: step by step

A pigmentation routine has two phases. The morning routine focuses on prevention (vitamin C, niacinamide, SPF), the evening routine on correction (an active ingredient, moisturising). Consistency is key: 3 to 6 months for PIH, 6 to 12 months for melasma and solar lentigines. Without daily SPF protection, any evening skincare is pointless.

Morning routine

1 Gentle cleansing with lukewarm water and a pH-balanced, sulphate-free gel.
2 Vitamin C serum, such as our Vitamin C Serum (ATIP).
3 Niacinamide serum or cream (2 to 5%), optional.
4 Moisturiser with ceramides or hyaluronic acid.
5 Broad-spectrum SPF 30+, such as our Protective Face Cream SPF 30 with mineral filters.

Evening routine

1 Thorough cleansing: first remove make-up (with micellar water or oil), then use a pH-balanced gel.
2 Active ingredient: Plus Pigment (a multi-mechanism treatment), azelaic acid (Plus Rosacea or Plus Akné, suitable for sensitive skin, PIH after acne and pregnancy), or retinol outside the acute phase.
3 A moisturising, barrier-supporting cream.

Frequency schedule for active ingredients
1. Weeks 1 to 2: 2 times a week in the evening.
2. Weeks 3 to 4: 3 times a week.
3. From week 5: every other evening.
4. Aim: daily application, if your skin tolerates it. For Plus Pigment, we recommend an intensive treatment phase of at least 6 weeks, followed by maintenance use.
Inside and out. Diet (antioxidants, vitamins C and E, selenium), hydration and sleep, when the skin regenerates most intensively, also play a role in pigmentation.

Recommended Dulcia products

For pigmentation, we recommend three key products covering both the morning and evening steps of your routine: Vitamin C Serum for antioxidant protection in the morning, Plus – First Aid for Dark Spots for targeted evening treatment and Protective Face Cream SPF 30 for daily sun protection.
Vitamin C Serum (20 ml )
The most common challenge with vitamin C in cosmetics is stability. We chose Ascorbyl Tetraisopalmitate, an oil-soluble vitamin C derivative that does not degrade with light or oxygen and is hydrolysed in the skin into active ascorbic acid. For us, this is the purest way to deliver vitamin C to the skin without compromising stability. Combine it with niacinamide in the morning or with Plus Pigment in the evening. → Vitamin C Serum
Plus – First Aid for Dark Spots (20 ml)
Our clear choice for active pigmentation is Plus Pigment, a multi-mechanism serum with eight ingredients: rainbow algae extract, daisy, AHA complex, ferulic acid, retinol-like sea fennel, Raykami, Actibiom and Jania Rubens. Apply it locally or over the whole face, in the evening only, with SPF essential during the day. The recommended intensive treatment lasts at least 6 weeks, followed by maintenance use. → Plus Pigment
Protective Face Cream SPF 30
Without sun protection, any depigmenting plan will fail. Our SPF 30 uses physical filters in micro form (without systemic absorption), protects against UVA, UVB and HEV blue light, is hypoallergenic and leaves no white cast. For us, it is the absolute foundation of a morning routine for pigmentation. For higher phototypes or frequent sun exposure, we also offer an SPF 50 version. → Dulcia SPF 30
An azelaic acid alternative. If your main concern is PIH after acne, sensitive skin, pregnancy or rosacea, we recommend Plus – First Aid for Acne or Plus – Soothing and Rosacea instead. Both contain azelaic acid, which tackles pigmentation and inflammation at the same time.

Frequently asked questions

How long does it take for dark spots to disappear?
Post-inflammatory hyperpigmentation (PIH) after acne responds to cosmetic skincare in 3 to 4 months with active treatment, or resolves spontaneously in 6 to 12 months. Melasma is more chronic: 6 to 12 months to stabilise, often with lifelong maintenance care. Solar lentigines (age spots) fade over 6 to 12 months; deeper spots may require IPL or laser treatment. Without daily SPF protection, you will not see results (Desai, 2014).

Can I treat dark spots during pregnancy?
Yes, but choose ingredients more carefully. Azelaic acid (US category B) is safe and clinically effective for melasma, which develops during pregnancy in 50 to 70% of predisposed women (Handel et al., 2014). Niacinamide is safe. Vitamin C is safe. Avoid retinol and retinoids; hydroquinone is banned in the EU even outside pregnancy. SPF 30+ and a hat are the most effective prevention for “chloasma gravidarum”.

Do lemon or bicarbonate of soda help with dark spots?
No, and they can make spots worse. Lemon juice contains furanocoumarins, which cause phytophotodermatitis after UV exposure, resulting in burns with long-lasting pigmentation. Bicarbonate of soda has a pH of around 9, while skin has a pH of 4.7 to 5.5; disrupting the barrier triggers inflammation, which directly stimulates melanogenesis according to Thornfeldt (2008). Clinically proven options are azelaic acid, niacinamide, vitamin C and AHA acids, not home remedies.

Will dark spots return after successful treatment?
The risk of recurrence is high with melasma and solar lentigines: melasma returns in more than 50% of women after active treatment ends; solar lentigines develop again with further UV exposure. PIH after acne may not return if the underlying cause (acne) is controlled. Long-term SPF use and maintenance treatment (low concentrations of niacinamide or azelaic acid) reduce the risk of recurrence by 80 to 90% (Desai, 2014).

When should I see a dermatologist about a dark spot?
If the spot meets any ABCDE criterion: Asymmetry, Border (irregular edge), Colour (multiple colours), Diameter over 6 mm, Evolution (rapid change). Also for a new spot after the age of 50, a bleeding or itchy lesion, an “ugly duckling” (different from the others), pigmentation not responding to 3 to 6 months of cosmetic skincare, or suspected actinic keratosis.

Is melasma hereditary?
A genetic predisposition exists: melasma is more common in women with phototypes III to V, those of Hispanic, Middle Eastern or South Asian ancestry, and women with a family history (Handel et al., 2014). Even with a predisposition, however, an external trigger is needed: UV radiation, hormones (pregnancy, contraception) or a combination of the two. Without these triggers, melasma does not appear even in genetically predisposed individuals.

Do I need laser or IPL treatment, or is skincare enough?
Most pigmentation responds to consistent cosmetic skincare with daily SPF protection. Laser and IPL (intense pulsed light) are suitable for deep solar lentigines that do not respond to cosmetics after 6 months, age spots on the hands and décolletage, and some forms of melasma. Caution: with dermal melasma, laser treatment can paradoxically cause post-inflammatory hyperpigmentation. Cosmetic skincare is always the first-line approach; professional procedures come into play when cosmetics fail.

Conclusion

Dark spots are a common, mostly harmless skin concern that can be managed with a patient combination of the right active ingredients and consistent sun protection. At Dulcia, we developed the multi-mechanism serum Plus – First Aid for Dark Spots and also offer a stabilised vitamin C serum and physical SPF 30. Together, these three products form a complete morning and evening routine for pigmentation. For sensitive skin, pregnancy or PIH after acne, we recommend choosing ranges with azelaic acid. If pigmentation does not improve after 3 to 6 months or shows ABCDE signs, see a dermatologist. Give your skin time and consistent care.

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