Reviewed by Boldpurity Science Team | ~12 min read | Last reviewed August 2026
Quick answer
Sun spots — medically solar lentigines — are flat brown marks from years of accumulated UV exposure. Not caused by age, despite the name, which is why they often appear from the thirties onward in people with heavy sun exposure.
The part that matters more than any routine: a melanoma subtype called lentigo maligna grows slowly and horizontally for years, so for a long stretch it looks like an ordinary flat brown mark. That overlap is why "it's just an age spot" is worth questioning.
The most useful check is not a checklist. It is the ugly duckling sign — does this mark look different from your others? A lesion that stands out from your personal pattern deserves attention even if it passes every letter of ABCDE.
The brown marks that collect on the backs of the hands, the cheeks and the chest have a misleading name. They are not really about age, and they have nothing to do with the liver. They are a record of accumulated sun exposure — and the single most important thing to know about them has nothing to do with fading them.
In this article
Section 01
What They Actually Are
Solar lentigines are flat, well-defined brown marks on skin with a long history of sun exposure. Beneath the surface they reflect a localised, persistent increase in melanin and in pigment-cell activity, built up over years of ultraviolet light. They appear exactly where the sun lands most — face, backs of the hands, forearms, upper chest and shoulders.
Both common names mislead. "Age spots" implies inevitability with age; "liver spots" is an old misnomer. In reality they mark cumulative UV exposure, which is why they commonly appear from the thirties onward in people who have spent significant time outdoors — and why the most useful intervention sits in the sun-protection aisle rather than the serum aisle.
For the underlying biology of how skin makes pigment at all, our piece on tyrosinase covers the enzyme at the centre of it.
Section 02 — Framework
Three Checks Before You Treat Anything
This is the most important section here, and it comes before the skincare deliberately. Improving the look of a confirmed benign mark is a cosmetic question. Deciding whether a mark is safe to treat at all is a medical one, and they are not the same task.
Why lentigo maligna is so easily missed
Lentigo maligna is a melanoma subtype occurring on chronically sun-damaged skin, and its defining behaviour is patience. It spreads horizontally within the epidermis for years before any vertical growth begins.
Which means that for a long period it presents as exactly what everyone assumes it is: a flat, brown, slowly enlarging mark on sun-exposed skin of an older adult. It is not subtle because it is rare — it is subtle because early on it genuinely resembles the thing it is mistaken for. That is the entire argument for having a changing mark looked at rather than covered with a serum.
Section 03
Sun Spots vs Freckles, Melasma And PIH
"Brown spot" is not a diagnosis. These have different causes and respond to different approaches — and the seasonal test in the second row is the quickest way to separate the two most confused.
On medium-to-deep skin
The differential shifts. Melasma and post-inflammatory pigmentation are considerably more common presenting complaints than solar lentigines, and all three can coexist on the same face — which is why self-diagnosis from a photo comparison is unreliable.
It also raises the stakes on treatment choice: an approach suited to lentigines can aggravate melasma, and energy-based procedures carry a higher risk of triggering post-inflammatory pigmentation on deeper skin.
Section 04
Prevention Comes First
Because solar lentigines are UV-driven, sun protection is simultaneously the prevention and the foundation of any treatment. Without it you are fading spots while continuing to produce and darken them — which is why topical results so often disappoint.
This applies at every skin tone. Deeper skin burns less readily, but UV still drives pigmentation, and as our piece on eumelanin and pheomelanin sets out, natural melanin provides only partial protection — meaningful, and well below a daily sunscreen.
Section 05
What Helps The Appearance
For marks a dermatologist has confirmed benign, several well-studied ingredients can help their appearance. Most act on pigment production or on turnover.
Hydroquinone is the historical dermatological reference for fading pigment. It is now prescription-only in the United States and prohibited in cosmetic products in the EU — which places it firmly with a dermatologist rather than on a shelf.
Expect any topical route to work over weeks to months, and to require continued sun protection to hold whatever it achieves.
Section 06
In-Clinic Options
Solar lentigines respond comparatively well to procedures, because they are discrete and well-defined targets rather than diffuse pigmentation. A dermatologist might discuss chemical peels, cryotherapy, or pigment-selective light and laser treatments.
Two caveats carry real weight. These are medical procedures and should follow confirmation that the mark is benign — treating an undiagnosed lesion can remove the visible evidence without addressing what produced it. And on deeper skin tones, energy-based treatments carry a higher risk of triggering post-inflammatory pigmentation, so a practitioner's experience with your specific skin tone matters more than which device they own.
FAQ
Frequently Asked Questions
What causes sun spots?
Years of accumulated ultraviolet exposure, which drives a localised and lasting increase in melanin in sun-exposed areas — face, backs of the hands, forearms, chest and shoulders. Despite the name "age spots" they reflect sun exposure rather than age, which is why they often appear from the thirties onward in people with significant outdoor exposure, and barely at all on skin that stays covered.
Are sun spots dangerous?
Most are harmless. The reason for caution is that a melanoma subtype called lentigo maligna spreads horizontally within the epidermis for years before growing downward, so early on it looks like an ordinary flat brown mark on sun-damaged skin. Any mark that is new, changing, unlike your others, or that itches, bleeds or fails to heal should be assessed by a dermatologist.
What is the ugly duckling sign?
The observation that most of a person's benign marks resemble each other, so a lesion standing out from that personal pattern deserves attention — even if it satisfies every ABCDE criterion individually. It is more intuitive than memorising five letters, and it uses your own skin as the reference rather than a textbook. If one mark simply looks like it does not belong with the others, that is worth acting on.
What is the difference between sun spots and freckles?
The simplest test is seasonal. Freckles darken in summer and fade in winter; solar lentigines persist year-round. Freckles are also usually smaller, strongly genetic and appear in childhood, while solar lentigines are larger, have well-defined borders and appear later as sun exposure accumulates.
Do sun spots go away on their own?
Generally no. Unlike freckles, solar lentigines are persistent and do not resolve by themselves. Their appearance can be improved with consistent sun protection and well-studied topicals, and procedures can be effective for confirmed benign marks. Notably, if a spot does change noticeably on its own, that is a reason to see a dermatologist rather than to assume it is fading.
Does sunscreen prevent sun spots?
Daily broad-spectrum sun protection is the most effective way to limit new solar lentigines and to stop existing ones darkening, since UV is their primary cause. It is also the foundation of any treatment — without it you are fading marks while continuing to create them, which is why topical results so often disappoint.
When should I see a dermatologist about a mark?
If it is new in adulthood, has changed in size, shape or colour, looks unlike your other marks, has an irregular or blurred border, contains more than one colour, is larger than about six millimetres, or itches, bleeds or does not heal. These features do not mean a mark is harmful — they mean it warrants an assessment rather than a cosmetic treatment. Photographing marks on your phone makes change answerable rather than a guess.
The bottom line
Sun spots are the skin's long-term record of UV exposure, not a marker of age. Sun protection is both the prevention and the foundation of anything else. But the point that matters more than any routine is this: lentigo maligna spends years looking like an ordinary flat brown mark, so a lesion that has changed, or that simply does not look like your others, belongs in front of a dermatologist rather than under a serum. Improve the appearance patiently — and check the ones that stand out.
Further reading
- Tyrosinase: the master switch of pigmentation
- Eumelanin vs pheomelanin: the science of skin colour
- Boldpurity Ingredient Directory
Scientific references
- Praetorius C, Sturm RA, Steingrímsson E. Sun-induced freckling: ephelides and solar lentigines. Pigment Cell & Melanoma Research. 2014;27(3):339–350.
- Ortonne JP, Pandya AG, Lui H, Hexsel D. Treatment of solar lentigines. Journal of the American Academy of Dermatology. 2006;54(5 Suppl 2):S262–S271.
- Abbasi NR, Shaw HM, Rigel DS, et al. Early diagnosis of cutaneous melanoma: revisiting the ABCD criteria. JAMA. 2004;292(22):2771–2776.
- Grob JJ, Bonerandi JJ. The "ugly duckling" sign: identification of the common characteristics of nevi in an individual as a basis for melanoma screening. Archives of Dermatology. 1998;134(1):103–104.
- Hakozaki T, Minwalla L, Zhuang J, et al. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer. British Journal of Dermatology. 2002;147(1):20–31.
- Chang TS. An updated review of tyrosinase inhibitors. International Journal of Molecular Sciences. 2009;10(6):2440–2475.
- European Parliament and Council. Regulation (EC) No 1223/2009 on cosmetic products (Annexes II and III; hydroquinone).
- Commission Regulation (EU) 2024/996 — restrictions on retinol, alpha-arbutin, arbutin and kojic acid (Annex III).
- US Food and Drug Administration. OTC hydroquinone status under the CARES Act, 2020.
- American Academy of Dermatology. Age spots and solar lentigines; when to have a mole or spot checked (consumer resources).
This article is provided for general educational purposes and reflects cosmetic-science understanding and regulatory frameworks at the time of writing. It is not medical advice and is not intended to diagnose, treat, cure or prevent any condition, including skin cancer. Most solar lentigines are harmless, but some serious skin conditions — including certain skin cancers — can resemble them; any new, changing or unusual mark should be assessed promptly by a qualified dermatologist. The ABCDE prompts and the ugly duckling sign are awareness aids for deciding when to seek an opinion, not diagnostic tools. No Boldpurity product is referenced, recommended or implied in this article, and no lightening, whitening, brightening or pigmentation-treatment claim is made for any product; ingredient discussion is general cosmetic science. Always patch-test new products and introduce active ingredients gradually. Aligned with the India CDSCO cosmetic framework, the Cosmetics Rules 2020 and the ASCI Code 2021.
