Frequently asked questions

Vitamin C is one of the most researched ingredients for a brighter, more even-looking skin tone. It's an antioxidant, it slows the enzyme that starts pigment production, and it supports collagen. Trends come and go; vitamin C has decades of evidence behind it, so it's at the heart of every Gleamin formula.

Read more in Vitamin C for dark spots: how it works and how to use it.

It's made for the skin of the bikini line, inner thighs and underarms, which is thinner and more delicate than facial skin. It pairs niacinamide, alpha arbutin and vitamin C, three gentle ingredients that work on different steps of pigment production. It's for external use only.

Read Brightening your bikini line: what works (and what scars).

Yes, every morning. UV is the biggest trigger for new pigment, so SPF 30 or higher protects everything vitamin C is working on, including on cloudy days and indoors near windows.

Most people notice skin looking fresher within the first few weeks. Skin renews itself roughly every four weeks, so give a routine 8 to 12 weeks of daily use to judge a more even-looking tone. Results vary from person to person. A photo in the same light on day one is the best way to see your progress.

We focus on one thing: skincare for melanin-rich skin prone to dark spots and uneven tone. Vitamin C is at the core of every formula, we pair it with gentle, well-researched ingredients, and we explain what's in the bottle in plain language, with sources.

Hyperpigmentation is skin that is darker in some areas than the surrounding skin, caused by extra melanin, the pigment that gives skin its colour. It shows up as dark spots, patches or an uneven skin tone. Common types include post-inflammatory hyperpigmentation (marks left after acne, cuts or irritation), sun spots from UV exposure, and darkening from friction. Hyperpigmentation is harmless in most cases and is especially common in medium to deep skin tones, where pigment cells respond more strongly to inflammation and light.

Dark spots on the face are caused by melanocytes producing extra melanin in one area. The most common triggers are: sun exposure (UV and visible light), inflammation from acne, eczema, bug bites or picking at skin, hormonal changes such as pregnancy or the pill, irritation from harsh products or hair removal, and certain medications. On darker skin tones, post-inflammatory hyperpigmentation after breakouts is the leading cause of dark spots.

Post-inflammatory hyperpigmentation (PIH) is a flat dark mark that appears after the skin has been inflamed or injured, for example by acne, a cut, a burn, eczema, a rash or an aggressive skincare product. Inflammation signals pigment cells to make more melanin, which is left behind as a brown, grey or dark patch once the skin heals. PIH is more frequent and longer-lasting in skin of colour (Fitzpatrick types IV to VI). Marks in the upper skin layer often improve over several months; deeper pigment can take a year or longer.

Hyperpigmentation is more common in darker skin because its melanocytes are more reactive: they produce more melanin, and produce it faster, in response to inflammation, friction, UV and visible light. The number of pigment cells is similar across skin tones; the difference is how much pigment they make and how it is distributed. This is why a pimple, scratch or rash is more likely to leave a lasting dark mark on melanin-rich skin, and why gentle, non-irritating skincare and daily sun protection matter so much.

Dark spots after acne (post-inflammatory hyperpigmentation) are a colour change only: the skin is flat and smooth, just darker. True acne scars change the skin's texture, either as indents (atrophic scars such as ice pick, boxcar or rolling scars) or raised bumps (hypertrophic or keloid scars). Red or purple marks, more visible on lighter skin, are called post-inflammatory erythema. Colour marks usually improve with time, sun protection and brightening ingredients, while textured scars generally need professional procedures.

Most dark spots from post-inflammatory hyperpigmentation improve over 3 to 12 months, depending on how deep the pigment sits and how dark the skin is. Pigment in the top layer of skin (epidermal) responds fastest, while deeper (dermal) pigment can last a year or more. Daily broad-spectrum sunscreen, avoiding picking and irritation, and consistent use of brightening ingredients such as vitamin C and niacinamide help dark spots look less noticeable sooner. Skin renews roughly every 28 days, so allow at least 8 to 12 weeks to judge a routine.

Yes. UV rays and visible light stimulate melanin production, so sun exposure darkens existing spots and triggers new ones. Research shows visible light, not just UV, causes stronger and longer-lasting pigmentation in medium to deep skin tones. Protect skin daily with a broad-spectrum SPF 30 or higher; tinted sunscreens containing iron oxides add protection against visible light. Reapply every two hours outdoors, and wear sunscreen even on cloudy days and near windows.

The best-researched over-the-counter ingredients for uneven skin tone are: vitamin C, which slows tyrosinase, the enzyme that starts melanin production; niacinamide (vitamin B3), which reduces the transfer of pigment to skin cells; alpha arbutin, kojic acid and licorice root extract, which also slow tyrosinase; and gentle exfoliating acids (AHAs, BHAs and PHAs), which speed up the turnover of pigmented cells. Combining ingredients that work on different steps, alongside daily sunscreen, gives the best results. A dermatologist can advise on prescription options for stubborn pigmentation.

Post-inflammatory hyperpigmentation often improves on its own over months as skin renews, provided the trigger (such as acne or irritation) is under control and the skin is protected from the sun. Without sun protection, dark spots tend to persist or darken. Sun spots and hormonal pigmentation are less likely to improve without help. Brightening ingredients, gentle exfoliation and daily SPF shorten the time it takes for skin tone to look more even.

To prevent dark marks after acne: do not pick, squeeze or scrub blemishes, because extra inflammation means extra pigment; calm breakouts early with gentle, non-stripping products; wear broad-spectrum SPF 30 or higher every day so UV and visible light don't deepen marks; and add an antioxidant such as vitamin C or niacinamide to your routine. The faster inflammation settles, the lighter and shorter-lived any post-inflammatory hyperpigmentation will be.

Darkening of the inner thighs and bikini line is very common and usually caused by friction (skin rubbing on skin or tight clothing), repeated irritation from shaving, waxing and ingrown hairs, hormonal changes, and leftover marks from razor bumps. Melanin-rich skin responds to this irritation with extra pigment. Reducing friction with breathable cotton and looser fits, spacing out hair removal, and using gentle products made for intimate skin all help. See a doctor if darkening appears suddenly or feels thick and velvety.

Dark underarms are commonly caused by friction, irritation from shaving or waxing, reactions to deodorant or antiperspirant ingredients, a build-up of dead skin cells, and the shadow of hair under the skin. Post-inflammatory hyperpigmentation from repeated irritation is the main reason in darker skin tones. Switching to gentle, fragrance-free products, reducing friction and exfoliating gently usually help. Thick, velvety dark patches can be a sign of acanthosis nigricans, which is linked to insulin resistance and should be checked by a doctor.

No. Lemon juice is highly acidic (pH around 2), which damages the skin barrier, and citrus is phototoxic: combined with sunlight it can cause burns, blisters and phytophotodermatitis, which leaves new dark marks. On melanin-rich skin, this irritation often makes hyperpigmentation worse, and it can also cause patchy light spots. Stable, properly formulated vitamin C gives the brightening benefit of citrus without the burn.

Yes, gentle chemical exfoliants help uneven skin tone by speeding up the shedding of pigmented surface cells. Alpha hydroxy acids (AHAs) such as glycolic and lactic acid work on the surface, beta hydroxy acid (BHA, salicylic acid) also clears pores, and polyhydroxy acids (PHAs) are the gentlest option for sensitive skin. On darker skin, start low and slow, 2 to 3 times a week, because over-exfoliation causes irritation that can trigger new hyperpigmentation. Always follow with sunscreen.

See a dermatologist or doctor if a dark patch appears suddenly, spreads quickly, changes shape or colour, bleeds or itches, feels thick or velvety, or doesn't improve after 3 months of sun protection and gentle care. Any mole or spot that is new, asymmetrical, has an irregular border or several colours should be checked promptly. A dermatologist can confirm the cause of hyperpigmentation and recommend professional or prescription options.

Yes. Vitamin C helps dark spots look less noticeable by slowing tyrosinase, the enzyme that starts melanin production, and by protecting skin from the UV-driven oxidative stress that triggers new pigment. Results are gradual: most people see a brighter, more even-looking tone after 8 to 12 weeks of daily use. Vitamin C works best alongside daily broad-spectrum sunscreen and pairs well with niacinamide, which works on a different step of pigmentation.

Yes, vitamin C and niacinamide can be used together. The old warning that they cancel each other out came from studies using pure ingredients at high heat, which doesn't reflect modern formulas. They are a well-matched pair for uneven skin tone: vitamin C slows melanin production, while niacinamide reduces the transfer of pigment to skin cells and supports the skin barrier. If your skin is sensitive, apply them at different times of day or introduce one at a time.

Yes, vitamin C is safe and well suited to dark skin. It helps with the concerns most common in melanin-rich skin, such as post-inflammatory hyperpigmentation and uneven tone, without bleaching healthy skin. The main risk for darker skin is irritation from a very low-pH formula, because irritation can trigger new pigment. Choose a stable, gentle form, introduce it gradually and wear sunscreen daily.

Niacinamide is vitamin B3. It helps uneven skin tone by reducing the transfer of melanin from pigment cells to surrounding skin cells, while vitamin C slows melanin production itself. Niacinamide also supports the skin barrier, reduces the look of redness and helps regulate oil. It is gentle and stable, works at 2 to 5% in most studies, and pairs well with vitamin C for hyperpigmentation-prone skin.