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.

Pure vitamin C breaks down quickly in light, air and water, so we rely on stable forms and protective packaging. We mostly use stable forms that hold up in a formula and convert to vitamin C in the skin: sodium ascorbyl phosphate, 3-O-ethyl ascorbic acid and tetrahexyldecyl ascorbate. We add botanicals naturally rich in vitamin C, such as Kakadu plum and desert lime, and choose packaging that keeps light and air out.

Gleamin makes vitamin C skincare for face, body and intimate skin, and we've developed more than ten formulas since 2019. Here's the current range.

For your face: the Vitamin C Clay Mask, our best-selling 10-minute mask with Kakadu plum, desert lime and turmeric; the Superactive Serum, our 15% vitamin C serum with 4% niacinamide; the Clarifying Brightening Cleanser, a cream-to-foam vitamin C cleanser (coming soon); the Advanced Brightening Moisturizer, a lightweight vitamin C cream with ceramides; and the Supernutrient Oil, a nourishing face oil with 3% vitamin C.

For your body and intimate skin: the Illuminating Intimate Serum for the bikini line and inner thighs; the Advanced Brightening Body Cream, a nightly body cream; the Glow Body Bar, an exfoliating vitamin C and turmeric bar (coming soon); and the Vitamin C Bright Hand Cream, a non-greasy hand cream (coming soon).

Shop what's available now in our Amazon store.

The Gleamin Vitamin C Clay Mask combines a vitamin C blend of Kakadu plum, desert lime and finger lime from Australia with turmeric root powder and extract, kaolin and Hydroclay to lift away oil and buildup, and aloe vera and glycerin to keep skin comfortable. It also contains kale extract, grape seed and safflower oils, and vitamin E. Iron oxides give it its warm color.

See the full ingredient list on the Vitamin C Clay Mask page or the Amazon listing, and read Inside Our Vitamin C Clay Mask.

The Gleamin Vitamin C Clay Mask is a 10-minute mask for skin prone to dark spots and uneven tone. Kaolin and Hydroclay absorb excess oil and lift away buildup, so right after rinsing, skin looks fresher, smoother and less shiny.

Its vitamin C comes from Kakadu plum, desert lime and finger lime, alongside turmeric, with aloe vera and glycerin to keep skin comfortable. Used 1 to 3 times a week with daily sunscreen, it helps skin look brighter and more even, so dark spots look less noticeable over 8 to 12 weeks. Results vary.

It's dermatologist tested and won two "Best Mask" awards in 2025. See Vitamin C Clay Mask results: what to expect week by week.

Gleam C is Gleamin's own vitamin C blend of Kakadu plum and desert lime, two Australian fruits naturally rich in vitamin C and antioxidant polyphenols. Instead of a single lab-made molecule, it gets its vitamin C from whole fruit extracts, so it brings along the fruits' other antioxidants too.

Gleam C is the vitamin C behind our Vitamin C Clay Mask. The blend still comes from Australia, where the mask was first made in 2019.

The Superactive Serum is Gleamin's most concentrated formula, with 15% vitamin C from two stable forms, 3-O-ethyl ascorbic acid and sodium ascorbyl phosphate. It pairs them with 4% niacinamide, bakuchiol (a plant-based alternative to retinol), turmeric leaf extract and hyaluronic acid. It is fragrance-free, vegan and free of essential oils, and comes in a 1 fl oz (30 mL) opaque pump bottle.

The full ingredient list is on the Superactive Serum page and its Amazon listing.

Yes, the Superactive Serum was fully reformulated in 2024 and is a different product from the earlier Gleamin vitamin C serum. Vitamin C went up to 15%, niacinamide went from 1% to 4%, and bakuchiol was added.

The texture changed too. The old serum was water-like; the new one is a true serum that feels slightly dewy or tacky at first and settles as it absorbs. If you used the old version, expect a different feel, and start every other night for the first week or two.

Yes. Vitamin C Advanced Energy Cream is the earlier name of what is now the Advanced Brightening Moisturizer. It's a daily face cream with 3% vitamin C plus vitamin C-rich botanicals, including oil-soluble tetrahexyldecyl ascorbate, plus three ceramides, hyaluronic acid, shea butter, turmeric and electrolytes (magnesium, manganese and zinc PCA).

It is fragrance-free and comes in a 1.7 fl oz (50 mL) jar. See the Advanced Brightening Moisturizer page.

The Supernutrient Oil is a rich, deeply hydrating face oil with 3% vitamin C in its oil-soluble form, tetrahexyldecyl ascorbate. Cloudberry seed oil makes up about 42% of the formula, alongside jojoba, pumpkin seed and turmeric oils, squalene and vitamin E. It is fragrance-free, vegan and dermatologist tested (repeat insult patch test on 52 adults, 2023), in a 1 fl oz (30 mL) dropper bottle.

Read more on the Supernutrient Oil page.

The Clarifying Brightening Cleanser is Gleamin's cream-to-foam face wash, previously called the Vitamin C Active Cleanser. It combines three forms of vitamin C (3-O-ethyl ascorbic acid plus desert lime and lilly pilly extracts) with a blend of BHA, PHA and AHA exfoliating acids, papaya enzyme and turmeric.

It cleanses and gently exfoliates without leaving skin tight, so it's a good first step in a brightening routine, especially for oily and breakout-prone skin. See the Clarifying Brightening Cleanser page.

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.

Yes, with a gentle start. The Superactive Serum balances its 15% vitamin C with niacinamide and hyaluronic acid. Patch test first, then use it once a day or every other day for the first week or two before moving to morning and night. If your skin feels irritated, space it out again and keep your routine simple.

Yes, you can use vitamin C serum after a clay mask. Rinse the mask off, pat your skin dry, then apply your serum and moisturizer. With the Vitamin C Clay Mask, that means cleanse, mask for about 10 minutes, rinse, then the Superactive Serum and moisturizer.

If your skin feels tight, warm or sensitive after masking, skip the serum that night and just moisturize, then use your vitamin C the next morning under sunscreen. More in What to use after a clay mask.

Use 1 to 2 pumps of the Superactive Serum for your face, and a little more if you include your neck. Apply it to clean, dry skin after cleansing and before moisturizer, morning and night.

More isn't better: extra serum won't speed up results and can irritate. A slightly tacky feel at first is normal and settles within a minute or two. In the morning, always finish with SPF 30 or higher.

Yes, the Supernutrient Oil and the Superactive Serum work well together. Apply the serum first to clean skin, then moisturizer, then press in 2 to 3 drops of oil as the last step, because oils seal in the water-based layers underneath.

Together they give you water-soluble vitamin C from the serum and oil-soluble vitamin C from the oil. Many people use the oil at night; in the morning, use it under sunscreen only if your skin is dry.

We focus on one thing: skincare for skin prone to dark spots and uneven tone, made with melanin-rich skin in mind. 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.

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.

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.

Tyrosinase is the enzyme inside pigment cells (melanocytes) that starts melanin production by converting the amino acid tyrosine into the building blocks of melanin. UV light, visible light, inflammation and hormones all switch it on, which is why they lead to dark spots.

Many brightening ingredients work by slowing tyrosinase, including vitamin C, alpha arbutin, kojic acid and licorice extract. Others, like niacinamide, act on a later step: the transfer of pigment to skin cells.

Vitamin C (ascorbic acid) does three main jobs in skin: it is an antioxidant that neutralizes free radicals from UV and pollution; it slows tyrosinase, the enzyme that starts melanin production, which helps skin tone look brighter and more even; and it is essential for collagen production, supporting smoother, firmer-looking skin. Used daily under sunscreen, topical vitamin C is one of the most researched ingredients for dullness, uneven tone and signs of sun damage.

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.

The best form of vitamin C depends on your skin. L-ascorbic acid is the most studied and potent form but is unstable and can sting. Stable derivatives are gentler: sodium ascorbyl phosphate (SAP) is water-soluble and suits sensitive and breakout-prone skin; 3-O-ethyl ascorbic acid is stable and penetrates well; tetrahexyldecyl ascorbate (THD) is oil-soluble and very gentle, ideal in creams and oils; magnesium ascorbyl phosphate (MAP) is mild and hydrating. For sensitive or darker skin prone to irritation, a stable derivative is often the better choice.

L-ascorbic acid is the pure, biologically active form of vitamin C. It is the most researched form in skincare and works at concentrations of about 10 to 20%, but only at a low pH (below 3.5), which can sting sensitive skin. It is also unstable: exposure to light, air and water oxidizes it, turning serums yellow then orange and reducing effectiveness. Look for opaque, airtight packaging and use it within a few months of opening.

For L-ascorbic acid, research shows effective concentrations between 10% and 20%; above 20% there is no added benefit and more irritation. Vitamin C derivatives work at different strengths because they convert to vitamin C in the skin: many are effective from about 3% upward. Beginners and sensitive skin can start at 5 to 10%. A well-formulated, stable product used every day matters more than the highest percentage on the label.

Morning is the best time to use vitamin C for most people, because its antioxidant protection helps defend skin against UV and pollution during the day. Apply it after cleansing and before moisturizer, then always finish with broad-spectrum sunscreen. Vitamin C can also be used at night, and stable derivatives work well either time. The most important thing is using it consistently every day.

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, but carefully. Using a low-pH L-ascorbic acid serum at the same time as AHAs or BHAs can irritate skin, and irritation can trigger hyperpigmentation in darker skin tones. A simple approach: vitamin C in the morning, exfoliating acids a few evenings a week. Gentle vitamin C derivatives such as sodium ascorbyl phosphate or tetrahexyldecyl ascorbate combine more easily with other actives.

A vitamin C serum turns yellow, orange or brown when the ascorbic acid oxidizes into dehydroascorbic acid after exposure to light, air or heat. An oxidized serum is less effective and may irritate skin or leave a temporary orange tint. Pale yellow is usually fine; dark orange or brown means it is time to replace it. Store vitamin C closed, cool and out of sunlight, or choose stable derivatives that resist oxidation.

Vitamin C can suit sensitive skin if you choose the right form. Low-pH L-ascorbic acid is the form most likely to sting or cause redness. Gentler derivatives, such as sodium ascorbyl phosphate, magnesium ascorbyl phosphate and tetrahexyldecyl ascorbate, work at a skin-friendly pH. Start with a lower concentration every other day, patch test on your inner arm first, and stop if you notice burning or irritation.

No. Vitamin C does not replace sunscreen. It is an antioxidant that helps neutralize free radicals caused by UV exposure and can boost your overall protection when used under sunscreen, but it does not absorb or block UV rays and has no SPF rating. Use vitamin C in the morning and always finish with a broad-spectrum SPF 30 or higher.

Most people notice brighter, fresher-looking skin from vitamin C within 3 to 4 weeks, and a more even-looking skin tone after 8 to 12 weeks of daily use. Collagen-related improvements in texture take longer, often 3 to 6 months. Results depend on the form and concentration of vitamin C, consistent daily use, and wearing sunscreen every day.

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 changing your natural skin tone. 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.

Kakadu plum (Terminalia ferdinandiana) is a small green fruit native to northern Australia with the highest natural vitamin C content recorded in any fruit, many times that of an orange. It is also rich in antioxidant polyphenols such as ellagic acid and gallic acid. In skincare, Kakadu plum extract is used as a botanical source of vitamin C and antioxidants for brighter, more even-looking skin.

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.

Sodium ascorbyl phosphate (SAP) is a stable, water-soluble form of vitamin C in which a phosphate group protects the part of the molecule that normally breaks down in light and air. Enzymes in the skin release active vitamin C after it's applied. SAP works at a skin-friendly pH of about 6 to 7, so it rarely stings, and it's usually used at up to 5%. It suits sensitive and breakout-prone skin.

Read the full guide to sodium ascorbyl phosphate.

Sodium ascorbyl phosphate is gentler and more stable than L-ascorbic acid, but less potent per percent. L-ascorbic acid is the active form with the most research, and it works at 10 to 20% at a pH below 3.5. SAP has to be converted by skin enzymes first, so less vitamin C becomes available, but it doesn't oxidize quickly or sting.

For sensitive or melanin-rich skin that reacts to irritation, a stable form you use every day often does more than a potent serum you can't tolerate.

3-O-ethyl ascorbic acid is a stable vitamin C derivative made by attaching an ethyl group to the third carbon of the vitamin C molecule, the spot where pure vitamin C usually breaks down. It dissolves in water and partly in oil, which helps it get into the skin, and it doesn't need a very low pH. It slows tyrosinase, the enzyme behind pigment production, and is usually used at about 0.5 to 3%.

You may also see it written as ethyl ascorbic acid or 3-0 ethyl ascorbic acid. Read the full guide to 3-O-ethyl ascorbic acid.

Tetrahexyldecyl ascorbate (THD) is an oil-soluble form of vitamin C, made by bonding vitamin C to fatty acid chains. Because it dissolves in oil, it can go into creams, balms and face oils where water-based vitamin C can't, and it's very stable and gentle, with little risk of stinging. Once in the skin, it's converted to active vitamin C. On labels it may also appear as THD ascorbate or ascorbyl tetraisopalmitate.

Read the full guide to tetrahexyldecyl ascorbate.

Tetrahexyldecyl ascorbate is effective as a gentle, stable antioxidant, but it has less research behind it than L-ascorbic acid. Lab and skin-model studies show it gets into the skin well, converts to vitamin C, and helps slow pigment production and protect against UV-related oxidative stress. Large human trials are limited.

It suits people who can't tolerate acidic serums, or who want vitamin C in a cream or oil. Use it daily for 8 to 12 weeks alongside sunscreen to judge it.

Oil-soluble vitamin C is a vitamin C derivative bonded to fatty acids so it dissolves in oil instead of water. The two main forms are tetrahexyldecyl ascorbate and ascorbyl palmitate. They blend into the skin's natural oils, stay stable in creams and face oils, and rarely sting.

They suit dry, mature and sensitive skin, and anyone who prefers a cream or face oil to a watery serum. Oily skin may prefer water-soluble forms, such as sodium ascorbyl phosphate, in a light serum.

A vitamin C toner can work, but it's usually a lighter dose than a serum. Toners are mostly water and often use low levels of stable forms such as sodium ascorbyl phosphate or ascorbyl glucoside, so they add a gentle antioxidant layer rather than a targeted step. They suit oily skin and people who like a light routine.

If dark spots or uneven tone are your main concern, a leave-on vitamin C serum used daily, followed by sunscreen, gives you more to work with.

The best packaging for vitamin C serum is opaque and airtight, such as an opaque bottle with a pump or an airless pump. Light, air and heat all oxidize vitamin C, especially L-ascorbic acid, and clear dropper bottles let in the most light and air every time you open them.

Stable derivatives are less sensitive, but good packaging still helps. Keep serums closed, away from windows and steamy bathrooms, and use them within the time on the open-jar symbol (such as 6M or 12M).

Yes, vitamin C serum expires, and once it's open it can lose strength before the date printed on the pack. Check the open-jar symbol (such as 6M or 12M), which shows how many months a product keeps after opening, as well as any expiry date.

Pure L-ascorbic acid serums break down fastest when light, air and heat get in, while stable forms such as sodium ascorbyl phosphate and 3-O-ethyl ascorbic acid keep longer. Replace a serum that has turned dark orange or brown, smells different or has changed texture. Keep the cap closed and store it somewhere cool and dark, away from a steamy bathroom. More in How to choose a vitamin C serum.

Yes, you can use vitamin C and retinol in the same routine, usually at different times of day. Apply vitamin C in the morning for antioxidant protection under sunscreen, and retinol at night, when it's more stable and your skin can adjust. Using both at once can irritate, especially with a low-pH L-ascorbic acid serum.

Start retinol 2 to 3 nights a week, moisturize well, and wear SPF 30 or higher every day, because retinol makes skin more sensitive to the sun.

It's best not to apply vitamin C and benzoyl peroxide at the same time. Benzoyl peroxide is a strong oxidizer, so it can oxidize vitamin C on the skin and reduce its benefit, and layering the two raises the risk of dryness and irritation.

Use vitamin C in the morning and benzoyl peroxide at night, or use a benzoyl peroxide wash and rinse it off before your vitamin C. Calming breakouts matters for preventing dark marks, so keep both in your routine, just apart.

A mild tingle for a few seconds after applying vitamin C serum can be normal, especially with L-ascorbic acid, which works at a low pH. Stinging that lasts more than a minute, burning, redness, itching or a rash isn't normal: rinse it off and stop using it.

Applying serum to damp skin or right after exfoliating makes tingling stronger, so apply it to dry skin. If tingling bothers you, switch to a gentler, stable form such as sodium ascorbyl phosphate.

Vitamin C supplements are unlikely to help dark spots much on their own. Your body tightly controls how much vitamin C reaches the skin from food and pills, so extra doses don't raise skin levels the way a product applied to the skin can.

Eating plenty of fruit and vegetables supports overall skin health, but for uneven tone, topical vitamin C, daily sunscreen and patience work better. Talk to a doctor before taking high-dose supplements, especially if you have kidney problems.

Vitamin C helps the flat dark marks left by acne look less noticeable, but it won't change textured acne scars much. Flat marks are post-inflammatory hyperpigmentation, and vitamin C slows the pigment production behind them over 8 to 12 weeks.

Indented scars, such as ice pick or boxcar scars, come from lost collagen. Vitamin C supports collagen but can't rebuild that depth. Textured scars usually need professional procedures such as microneedling or laser, so ask a dermatologist.

A vitamin C face mask gives skin a short, concentrated dose of vitamin C and antioxidants, usually alongside clay or hydrating ingredients, for a fresher, brighter look right after rinsing. Used 1 to 3 times a week for 8 to 12 weeks, it can help skin look more even. Many use fruit sources like Kakadu plum or stable vitamin C derivatives.

Rinse-off masks have less contact time than serums, so they work best alongside a daily leave-on vitamin C serum and sunscreen.

Vitamin C hand cream can help dark spots on the hands look less noticeable over time, especially sun spots from years of UV. Hands get a lot of sun and are washed often, so a cream with a stable vitamin C plus moisturizing ingredients works well as a leave-on step.

Apply it after washing, at least twice a day, and put sunscreen on the backs of your hands. Expect 8 to 12 weeks, and have any spot that changes checked by a doctor.

Yes, vitamin C works on the body as well as the face, for dark spots on the arms, legs, chest, back and shoulders. Body skin is thicker, so lotions and creams with stable forms like tetrahexyldecyl ascorbate or sodium ascorbyl phosphate are practical for large areas.

Don't use a strong, low-pH face serum on intimate skin, which is thinner and easily irritated. Apply vitamin C daily after showering, and use sunscreen on exposed areas.