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. 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.

Vitamin C Clay Mask: our best-seller, a 10-minute mask with Kakadu plum, desert lime and turmeric. Superactive Serum: our most concentrated formula, with 15% vitamin C and niacinamide. Clarifying Brightening Cleanser: a cream-to-foam cleanser with vitamin C and gentle exfoliating acids. Advanced Brightening Moisturizer: vitamin C with three ceramides and hyaluronic acid. Illuminating Intimate Serum: niacinamide, alpha arbutin and vitamin C for the bikini line, inner thighs and underarms.

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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. Patch test first, then use it every other night for the first week or two before moving to daily use. If your skin feels irritated, space it out again and keep your routine simple.

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.

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.

Vitamin C (ascorbic acid) does three main jobs in skin: it is an antioxidant that neutralises 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 oxidises 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 oxidises into dehydroascorbic acid after exposure to light, air or heat. An oxidised 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 neutralise 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 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.

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.