Vitamin C is one of skincare’s most loved (and most misunderstood) ingredients. It brightens the complexion, supports collagen, softens pigmentation, and provides antioxidant defence against environmental damage. But here’s the twist: there isn’t one vitamin C—there are many. Each form has its own personality, strengths, stability quirks and ideal skin types. Below is a breakdown of the most common (and most effective) vitamin C forms found in skincare today.
1. L-Ascorbic Acid (LAA)
The Pure, Potent Original
What it is: The unmodified, biologically active form of vitamin C.
Why it’s loved: Fast penetration and strong evidence for boosting collagen, fading pigmentation and increasing brightness.
Challenges: Highly unstable—oxidises quickly when exposed to air, water and light. Low pH (≈3.0) formulas required for absorption can irritate sensitive skin.
Best for: Experienced users, resilient skin types, those targeting strong pigmentation or dullness. Typical concentration: 10–20%.
2. Sodium Ascorbyl Phosphate (SAP)
The Gentle Defender
What it is: A stable, water-soluble vitamin C derivative that converts into L-ascorbic acid inside the skin.
Superpower: Anti-acne activity—SAP has been shown to reduce inflammation and help prevent breakouts.
Why choose it: Less irritating than LAA, extremely stable, and ideal for everyday use.
Best for: Acne-prone, sensitive or reactive skins; people who want antioxidant + brightening benefits without the sting.
Typical concentration: 5–10%.
3. Magnesium Ascorbyl Phosphate (MAP)
The Hydrating Brightener
What it is: A water-soluble and gentle vitamin C ester.
What makes it unique:
• Excellent for hydration (increases skin moisture levels)
• Very low irritation
• Particularly effective for brightening
Best for: Dry, dehydrated, or sensitive skins wanting a mild but effective brightening ingredient.
Typical concentration: 3–10%.
4. Ascorbyl Glucoside
The Slow-Release Multitasker
What it is: Vitamin C bound with glucose for enhanced stability.
Why it works: Gradually converts to pure vitamin C once absorbed, offering steady antioxidant protection.
Benefits: Brightens, firms, and plays well with other active ingredients.
Best for: All skin types, especially those wanting long-term clarity and radiance.
Typical concentration: 5–12%.
5. Ethylated Ascorbic Acid / 3-O-Ethyl Ascorbic Acid
The High-Tech Performer
What it is: A partially stabilised version of vitamin C where an ethyl group protects the molecule from oxidation.
Why it’s trending:
• More stable than LAA
• Penetrates well
• Effective for fading pigmentation, including PIH and melasma
Best for: Those chasing serious brightness and even tone without the instability of LAA.
Typical concentration: 10–20%.
6. Tetrahexyldecyl Ascorbate (THD)
The Luxe Oil-Loving Powerhouse
What it is: An oil-soluble, highly stable vitamin C that penetrates deeper into the skin thanks to its lipid affinity.
What makes it elite:
• Strong collagen-stimulating effects
• Potent brightening
• Excellent compatibility with retinoids and ceramide-rich formulas
Best for: Mature, dry, or barrier-compromised skins wanting a richer texture with maximum results.
Typical concentration: 5–20%.
7. Ascorbyl Tetraisopalmitate (ATIP)
The Silky Antioxidant Specialist
What it is: Another oil-soluble ester, similar to THD but slightly lighter in feel.
Benefits:
• Enhances UV protection (used with sunscreen, not instead of)
• Improves hyperpigmentation
• Less irritating than pure ascorbic acid
Best for: People who love dry oils, silky textures and long-term tone correction.
Typical concentration: 3–10%.
8. Ascorbyl Palmitate
The Classic Antioxidant Add-On
What it is: A fat-soluble antioxidant form often used in creams.
Strengths: Good for antioxidant protection and formula stability.
Limitations: Contributes less visible brightening or collagen-boosting compared with the newer derivatives or pure LAA.
Best for: Supporting antioxidant defence in moisturisers.
Typical concentration: 0.5–3%.
Which Form Is Best?
There’s no single “best” vitamin C—only the best match for your skin type and goals.
Skin Concern / Goal Best Vitamin C Types
Dullness & rapid brightening L-Ascorbic Acid, Ethylated Vitamin C
Pigmentation / uneven tone Ethylated Vitamin C, THD, ATIP
Sensitive or reactive skin SAP, MAP, Ascorbyl Glucoside
Acne-prone skin SAP
Dry or mature skin THD, ATIP
Everyday antioxidant protection Ascorbyl Glucoside, SAP, MAP
How to Use Vitamin C Safely
• Apply in the morning for antioxidant protection (or both AM + PM depending on the form).
• Pair with SPF daily—vitamin C + sunscreen is a powerhouse duo.
• Introduce slowly if sensitive.
• Store in airtight, opaque packaging to prevent oxidation.