Vitamin C Serum
Vitamin C Serum
Product Description
Product overview
A bold, waterless 30% L-Ascorbic Acid serum suspended in a silicone base — designed to deliver the highest clinically effective concentration of pure Vitamin C in a stable, long-lasting format. Targets hyperpigmentation, dullness, fine lines, and free-radical damage without the oxidation risk that plagues water-based Vitamin C formulas.
30% Pure L-Ascorbic Acid
The highest clinically proven concentration. L-Ascorbic Acid is the gold-standard form of Vitamin C, scientifically validated for collagen synthesis, brightening, and antioxidant protection.
Texture & feel
SENSORY30% Pure L-Ascorbic Acid
The highest clinically proven concentration. L-Ascorbic Acid is the gold-standard form of Vitamin C, scientifically validated for collagen synthesis, brightening, and antioxidant protection.
Anhydrous Silicone Base = No Oxidation
Water-free silicone formula eliminates the instability problem. Pure Vitamin C won't turn orange or lose potency — the formula stays effective far longer than typical water-based serums.
Instant Smoothing & Primer Effect
Dimethicone creates a silky, blurring veil that minimises the appearance of pores and fine lines on contact, making it an excellent primer base for makeup application.
Exceptional Value
At under $15 for a 30% pure ascorbic acid serum, this is one of the most affordable high-concentration Vitamin C formulas on the market — typically only found in serums costing $50–$170+.
Free Radical & Pollution Defence
Used in the AM, high-dose ascorbic acid acts as a powerful antioxidant shield, neutralising UV-induced free radicals and environmental pollutants that accelerate premature skin ageing.
Hyperpigmentation & Dark Spot Fader
L-Ascorbic Acid inhibits tyrosinase, the enzyme responsible for melanin overproduction. With consistent use, dark spots, acne marks, sun spots, and uneven skin tone visibly improve.
Safety & compatibility
SAFEVitamin C (L-Ascorbic Acid) is not a retinoid, salicylic acid, or hydroquinone. It is considered safe to use during pregnancy and breastfeeding. Always consult your healthcare provider.
This product is free from ferments, fatty acids, esters, and problematic oils that feed Malassezia yeast. The 4-ingredient silicone base is considered fungal acne safe.
Dimethicone is a low-comedogenic silicone (rating 1–2) widely accepted as safe for acne-prone skin. No pore-clogging oils, waxes, or fats are present in this formula.
30% is a high concentration of L-Ascorbic Acid. Those new to Vitamin C or with reactive, sensitised skin may experience stinging, redness, or irritation. Start 2–3x per week and build up.
Do not layer simultaneously with AHAs (glycolic, lactic), BHAs, or Niacinamide. These combinations can increase skin sensitivity and irritation. Alternate — use Vitamin C in AM, actives in PM.
Contains no added fragrances, essential oils, or known contact allergens, making it suitable for those with fragrance sensitivities. A faint neutral scent from raw ascorbic acid may be present.
Free from parabens, sulfates, and formaldehyde-releasing preservatives. The silicones used (Dimethicone, Polysilicone-11) are well-studied, safe, and non-toxic for topical use.
This formula layers best when mixed directly with a water-based HA serum or applied on slightly damp skin. Applying on dry skin alone may produce a paste-like texture that's difficult to spread evenly.
Ingredient breakdown
INGREDIENTSAscorbic Acid (Vitamin C) ~30%Proven
The gold-standard form of topical Vitamin C. L-Ascorbic Acid (LAA) is the most researched, most bioavailable, and most potent form of Vitamin C available in skincare. At 30%, this is at the upper ceiling of the effective range (5–20% is the sweet spot; above 20% increases risk of irritation without proportionally better results, but the anhydrous base moderates delivery). It functions as a powerful antioxidant, collagen co-factor, and melanin inhibitor.
- Collagen Synthesis: LAA is an essential co-factor for prolyl and lysyl hydroxylase enzymes, which are required for collagen cross-linking. Studies show 5–20% topical LAA significantly increases collagen production in dermal fibroblasts.
- Antioxidant Action: Neutralises reactive oxygen species (ROS) from UV radiation and pollution, reducing oxidative DNA damage to skin cells.
- Melanin Inhibition: Inhibits tyrosinase (the rate-limiting enzyme in melanogenesis), reducing production of excess melanin and fading hyperpigmentation.
- UV Synergy: When applied before sunscreen, LAA provides a secondary antioxidant layer that enhances the effectiveness of SPF against photoaging.
- Stability: LAA is unstable in water-based formulas — this waterless silicone base resolves that problem. Unlike water-based Vitamin C serums that oxidise within weeks, this formula remains potent for up to 12 months after opening.
Dimethicone Base (Highest %)Proven
The primary carrier and sensory ingredient in this formula. Dimethicone is a widely used silicone polymer that creates a smooth, silky film on skin. In this formula, it serves a dual purpose: delivering Vitamin C to the skin surface while providing an instant cosmetic blurring and occlusive effect. It is the main reason this serum doubles as a primer.
- Occlusive Properties: Forms a breathable film on skin that reduces transepidermal water loss (TEWL), helping to lock in moisture.
- Non-Comedogenic: Despite being an oil-like texture, dimethicone is scientifically non-comedogenic (pore-clogging rating: 1–2/5) and is widely used in acne-safe formulations.
- Scar Support: Silicone gels and sheets using dimethicone as a base have been clinically used to soften and improve the appearance of scars.
- Stability Vehicle: The anhydrous (water-free) silicone environment prevents the oxidative degradation of L-Ascorbic Acid, dramatically extending shelf life vs. aqueous serums.
Polysilicone-11 Trace AmountPromising
A silicone elastomer that gives the formula its unique velvety, bouncy texture. Polysilicone-11 acts as a film-forming agent and texture enhancer, providing the soft-focus, skin-smoothing effect users notice on application. It creates a subtle structure in the formula that helps distribute the high-dose Vitamin C more evenly across the skin surface.
- Film Former: Creates a micro-mesh on skin that gives a blurred, soft-focus finish — ideal under makeup.
- Texture Modifier: Responsible for the silicone-cream consistency that differentiates this from both a serum and a traditional cream.
- Safety Profile: Silicone elastomers are well-tolerated by all skin types, non-irritating, and free from known allergens.
PEG-10 Dimethicone Trace AmountProven
A silicone-based emulsifier that helps bind the ingredients together and supports the overall formula stability. PEG-10 Dimethicone ensures a homogeneous texture so the Vitamin C remains evenly dispersed throughout the product rather than settling or separating.
- Emulsifier: Reduces surface tension between ingredients, creating a uniform and stable suspension of Vitamin C in the silicone matrix.
- Conditioning: Provides additional skin-softening properties and helps the formula spread more smoothly on application.
- pH Note: PEG-10 Dimethicone performs best in neutral or near-neutral pH environments — well-suited to the relatively stable pH of an anhydrous formulation.
4 ingredients
Dimethicone, Ascorbic Acid, Polysilicone-11, PEG-10 Dimethicone
Where it fits in your routine
ROUTINEPro tip: Apply after your Hyaluronic Acid Serum — or mix a pea-sized amount of both together in your palm before applying. This dilutes the Vitamin C concentration slightly, improves spreadability, and dramatically reduces any stinging sensation for beginners.
How to use
HOW TO USECleanse Thoroughly
Begin with a clean face. Use your regular gentle cleanser morning or evening. Pat skin dry — applying on slightly damp skin can actually help this silicone formula blend more easily.
Apply Your HA Serum First (Recommended)
Apply The INKEY List Hyaluronic Acid Serum or any water-based hydrating serum first. Wait 30 seconds for it to absorb. Alternatively, mix both serums together in your palm before application.
Dispense a Pea-Sized Amount
Squeeze a pea-sized amount (approximately 0.3–0.4 ml) directly from the tube. Less is more with this high-concentration formula. Using too much product increases the risk of irritation and pilling.
Press & Pat into Face and Neck
Gently press and pat the serum into skin — do not rub vigorously. The silicone base responds better to pressing motions. Spread outward from the centre of the face toward the hairline and jawline.
Wait 60 Seconds, Then Layer
Allow 60 seconds for the silicone film to settle before applying the next product. This prevents pilling. Follow with eye cream, moisturiser, and — critically — a broad-spectrum SPF 30+ in the morning.
Frequency: Start Slow, Build Up
Beginners: use 2–3 times per week in the AM. After 2–3 weeks, increase to daily AM use if skin tolerates it well. Can also be used PM, though AM is preferred for maximum antioxidant photoprotection synergy with SPF.
Who is it for?
WHOPerfect for you if:
- You want an affordable, stable, high-potency Vitamin C serum
- You've used Vitamin C before and your skin tolerates actives well
- You struggle with dullness, uneven tone, dark spots, or sun damage
- You want a serum that doubles as a makeup primer
- You have oily or combination skin that benefits from silicone-based formulas
- You're looking for a fragrance-free, minimalist formula
- You prefer a waterless formula that won't oxidise quickly in your routine
Consider alternatives if:
- You are completely new to Vitamin C or have very reactive skin — start with 10–15% instead
- You dislike silicone textures or find dimethicone-heavy products pill under makeup
- You prefer a watery, gel, or serum-drop formula texture
- You want additional ingredients like Vitamin E, Ferulic Acid, or Hyaluronic Acid in one product
- You have a known sensitivity to PEG-based ingredients
- You are prone to milia and are cautious about occlusive products
Skin type compatibility
SKIN TYPESSilicone base leaves a velvety, non-greasy finish. Ideal for oily skin — absorbs quickly without adding shine. No occlusive oils that could worsen oiliness.
The occlusive silicone base helps seal in hydration. Best results when layered over a hydrating HA serum first, then followed with a richer moisturiser. May feel slightly drying without additional hydration steps.
One of the best skin types for this product. Silicone base controls shine in the T-zone while the small quantity needed means minimal product on drier cheek areas. Mix with HA for optimal balance.
30% L-Ascorbic Acid is potent — sensitive skin users may experience redness or stinging. Start with 1–2x per week, always diluted with HA serum. Consider starting with the 15% EGF version for an easier introduction.
Non-comedogenic, fungal-acne safe, and free from oils and pore-clogging ingredients. Vitamin C's tyrosinase inhibition helps fade post-acne dark marks and hyperpigmentation over time.
High-dose LAA is one of the most researched anti-ageing ingredients. Stimulates collagen production, fights free radicals, and the dimethicone base provides an instant plumping and wrinkle-blurring effect.
Results timeline
MONTH 3+Instant Glow & Skin-Blurring Effect
Dimethicone and Polysilicone-11 create an immediate soft-focus, smooth-skin effect. Pores appear minimised and skin looks more even — great as a makeup primer base from day one.
~95% noticed smoother texture on first useBrighter Complexion & Reduced Dullness
Ascorbic Acid begins inhibiting melanin production and quenching free radicals. Most users report a visible improvement in skin radiance and a more "awake" look after 2 weeks of consistent AM use.
~70% noticed improved glow by week 3Fading Dark Spots & Hyperpigmentation
With consistent daily use, hyperpigmentation, post-acne marks, and sun spots begin to visibly lighten. Tyrosinase inhibition is a cumulative process — the longer you use it, the more dramatic the fading.
~65% saw visible dark spot improvement at 6 weeksImproved Skin Firmness & Fine Line Reduction
Collagen synthesis stimulated by L-Ascorbic Acid begins to show structural improvement. Fine lines appear softened, skin looks and feels firmer, and overall skin quality — texture, tone, and resilience — is measurably improved.
~55% reported noticeable firmness improvement at 3 monthsRatings by platform
7K+ REVIEWSPros & cons
BALANCEDPraised
- One of the most affordable 30% L-Ascorbic Acid serums available globally
- Anhydrous formula prevents oxidation — stays potent long after opening
- Doubles as a makeup primer — smooth, velvety, skin-blurring finish
- Only 4 ingredients — extremely minimal formulation
- Fragrance-free, allergen-free, FA-safe, pregnancy-safe
- Visible brightening results within 2–3 weeks of consistent use
- Does not discolour or turn orange (unlike water-based Vitamin C serums)
- Mixable with HA serum for a beginner-friendly diluted dose
Criticized
- Thick, paste-like texture is difficult to blend when used alone on dry skin
- Can pill under some moisturisers if not given enough time to settle
- No supporting actives (Vitamin E, Ferulic Acid) unlike competitor formulas
- 30% concentration may be too potent for Vitamin C beginners or reactive skin
- Tube packaging makes it hard to see remaining product or control dispense amount
- Slight burning or stinging on application is commonly reported
- Silicone-heavy formula is not suitable for those avoiding silicones
Budget-friendly alternatives (dupes)
DUPESNearly identical concept: 30% L-Ascorbic Acid in a silicone suspension base. The Ordinary's version is slightly grittier in texture due to suspended particles rather than the smoother emulsified formula of The INKEY List version. Both are waterless, stable, and anhydrous. The INKEY List version has a smoother silicone feel and slightly better spreadability.
A water-based, lower-concentration (12.5%) ascorbic acid serum with a lighter, more fluid texture. Much gentler and better suited for Vitamin C beginners or sensitive skin. Less potent than 30% but also far less likely to cause irritation. Water-based formula means it's less stable over time and may oxidise faster after opening.
Water-based serum with Sodium Ascorbyl Phosphate (a Vitamin C derivative), plus Hyaluronic Acid and Vitamin E. More hydrating formula with a more pleasant application experience, but uses a less potent Vitamin C derivative rather than pure L-Ascorbic Acid. Better for beginners and dry skin types; less potent for dark spot correction.
Comparison with competitors
SIDE-BY-SIDESkinCeuticals C E Ferulic
Storage & shelf life
12 MONTHS12 months after opening. The waterless silicone formula significantly extends the shelf life of Vitamin C compared to water-based formulas, which typically only last 3–6 months before oxidising.
Store in a cool, dry place between 15–25°C. Avoid direct sunlight and temperature extremes. Unlike water-based Vitamin C serums, refrigeration is not necessary — but cool storage extends potency.
Opaque squeeze tube. The tube format limits air and light exposure, helping to preserve the ascorbic acid. However, it can be difficult to gauge remaining product or control exact dispense amount near the end.
Yes — at 30 ml, it is within TSA/international carry-on limits (under 100 ml). Lightweight tube is easy to pack. No risk of oxidation from temperature changes during travel, unlike water-based Vitamin C serums.
Frequently asked questions
FAQYes — The INKEY List Vitamin C Serum is considered safe to use during pregnancy and breastfeeding. L-Ascorbic Acid (Vitamin C) is not a retinoid, salicylic acid, or hydroquinone — the ingredients that are typically advised against during pregnancy. Vitamin C is a naturally occurring antioxidant found in food and skincare and is generally regarded as safe for pregnant and nursing individuals. As always, consult your healthcare provider or dermatologist before changing your skincare routine during pregnancy.
Yes — The INKEY List Vitamin C Serum is considered fungal acne (Malassezia folliculitis) safe. The formula contains only 4 ingredients: Dimethicone, Ascorbic Acid, Polysilicone-11, and PEG-10 Dimethicone. None of these ingredients are ferments, esters, fatty acids, or oils that are known to feed Malassezia yeast. Silicones and ascorbic acid are both well-regarded as safe for fungal-acne-prone skin. This product is free from problematic common fungal acne triggers such as plant oils, fatty acids, and fungal-feeding esters.
Do not use simultaneously in the same application. The INKEY List specifically advises against layering this serum directly with AHAs (glycolic, lactic, mandelic acid), BHAs (salicylic acid), PHAs, Niacinamide, and Retinols in the same routine step — as these combinations can significantly increase skin irritation and sensitivity. The recommended approach is to use Vitamin C Serum in the morning and reserve AHAs, BHAs, or Retinol for the evening routine. If you want to use Niacinamide, opt for The INKEY List's 15% Vitamin C + EGF Serum instead, which uses a Vitamin C derivative (Ascorbyl Glucoside) that is compatible with Niacinamide.
This serum is best suited for oily, combination, acne-prone, and normal skin types who have some prior experience with Vitamin C. The silicone base provides a matte, velvety finish that suits oily and combination skin well. It is also excellent for mature skin concerned with anti-ageing benefits. Dry skin can use it, but should layer it over a hydrating serum and follow with a richer moisturiser. Sensitive skin or complete Vitamin C beginners should start cautiously — use just 2–3x per week mixed with a HA serum, and consider whether the lower-concentration 15% EGF version might be a gentler starting point.
You will notice an immediate cosmetic smoothing and glow effect from the silicone base on day one. For active Vitamin C results: most users see improved radiance and reduced dullness within 2–3 weeks. Visible fading of hyperpigmentation, dark spots, or post-acne marks typically begins after 4–6 weeks of consistent daily AM use. Firmness improvements and fine line reduction are longer-term benefits — expect to see meaningful collagen-driven changes after 3+ months. Results depend on consistency, sun protection habits (SPF daily is critical), and your individual skin's responsiveness to actives.
Apply The INKEY List Vitamin C Serum as Step 4 in your AM routine: after cleanser (Step 1), toner (Step 2), and a water-based HA serum (Step 3). It goes before eye treatment, moisturiser, and SPF. The brand specifically recommends applying the HA Serum first, then this product on top — or mixing both together in your palm before applying. This improves spreadability and reduces the risk of stinging. Always follow with SPF in the morning — Vitamin C's antioxidant benefits are maximised when paired with a broad-spectrum sunscreen.
No — The INKEY List Vitamin C Serum is non-comedogenic with a rating of 1/5. The primary ingredient, Dimethicone, is a silicone polymer widely recognised as non-pore-clogging (comedogenic rating 1–2/5). It contains no plant oils, waxes, fatty acids, or esters that are commonly associated with clogged pores or comedone formation. The formula is free from all known pore-clogging components. Acne-prone skin users typically respond well to silicone-based Vitamin C formulas.
The INKEY List Vitamin C Serum has a PAO (Period After Opening) of 12 months. This is significantly longer than typical water-based Vitamin C serums, which oxidise within 3–6 months of opening. The anhydrous (waterless) silicone formula eliminates the primary cause of L-Ascorbic Acid degradation — exposure to water and oxygen. Unlike water-based Vitamin C serums that turn orange or yellow when oxidised, this formula remains visually stable throughout its usable life. Store in a cool, dry place away from direct sunlight to maximise potency.
Verdict: The INKEY List Vitamin C Serum 30% is a genuinely clever formulation that solves one of skincare's most persistent problems — the instability of pure L-Ascorbic Acid — by suspending it in an anhydrous silicone base. At under $15 for a 30% concentration, it represents extraordinary value in a market where high-dose Vitamin C serums routinely cost $50–$180+. The waterless format ensures your Vitamin C stays potent for 12 months, no refrigeration required, and no orange-tinted oxidation waste. The silicone base also delivers a bonus: an immediate primer-like smoothing effect that makes skin look and feel polished before makeup. The trade-off is texture — used alone on dry skin, the formula can turn paste-like and pill. The solution is simple: mix with a HA serum first, and the experience transforms completely. Not for sensitive-skin beginners (30% is strong), but for experienced Vitamin C users or those battling stubborn dark spots and dullness on a budget, this is one of the smartest active serums available today.
Product Overview
Quick product notes are a great way to check if a product is free from commonly avoided ingredients by skincare enthusiasts. These preferences come about for different reasons depending on the ingredient such as personal experiences, sensitivities, health preferences & etc.
Just because a product is not free from a common preference does not mean it's a bad product! You can make a personal decision whether or not you want to use a product that contains these ingredients or not - click the labels of the preference to read more about them.
Quick Product Notes
Ever used a product that promised a certain effect but provided no results? It might not have contained any notable ingredients that could have been responsible for that promised effect. It doesn't matter what the marketing or packaging «promises» it can do, if it doesn't contain anything that can help - then the likelihood of it helping is low.
We help you identify key notable ingredients that have been shown to help with effects such as acne-fighting, brightening, UV-protection, wound healing & anti-aging to help you achieve your skincare goals smarter. Please note that different notable ingredients have varying levels of research behind them, some are extremely well proven yet some have mixed research in their efficacy.
Just because a product doesn't contain any notable ingredients doesn't mean it's bad. And a product with notable ingredients (or even many) doesn't necessarily guarantee the efficacy of the product performing these effects either. There are other factors such as ingredient quality, concentration and formulation that will ultimately determine this.
Be smart and use this as just a starting point for you to make more informed and smarter choices and compare it with reviews to see if the product is right for you
Notable Effects & Ingredients
Why are some products great for some people and horrible for others? Well everyone has different skin types and different reactions to the same ingredients.
We've identified a range of ingredients that are commonly regarded as potentially good or bad for those with Dry, Oily/Acne-Prone or Sensitive skin.
A product that contains good or bad ingredients for your skin type doesn't always flat out make the entire product good or bad for your skin. There are other factors such as ingredient quality, concentration and formulation that will ultimately determine your skins reaction.
One of the best ways to use this section is to troubleshoot products you've had bad experiences with in the past. Check if it contains any of the marked ingredients to point out suspect ingredients to avoid in the future!
Ingredients Related to Skin Types
Ingredient Safety Breakdown refers to the percentage % of ingredients in different risk categories as classified by EWG (Environment Working Group) if they are available. There are almost endless cosmetic ingredients and they are one of the few organisations globally that have assigned ratings to a lot of the more commonly used ingredients which is why we reference them.
EWG is seen by many to be more on the alarmist side in their assignment of health ratings resulting in rating ingredients as riskier than they actually are. We recommend using this a reference point rather than a strict guide of ingredient safety and to always do further research if into ingredients that you may find suspect.
Ingredient Safety Breakdown
Product ingredient list
| EWG | CIR | Ingredient Name & Cosmetic Functions | Notes |
|---|---|---|---|
| 3 |
Dimethicone
Skin Conditioning, Emollient, Antifoaming Agent, Skin Protecting
|
|
|
| 1 |
Ascorbic Acid
Skin Conditioning, Masking, Fragrance, Antioxidant, Ph Adjuster, Buffering Agent, Buffering
|
Promotes Wound Healing
Redness
Dark Spots
Texture
Pores
|
|
| 1 |
Polysilicone-11
Film Forming
|
|
|
| 3 |
PEG-10 Dimethicone
Skin Conditioning, Hair Conditioning
|
|







