Ingredient Science Hub

Not All Vitamin C is the Same

From the gold-standard L-Ascorbic Acid to the ultra-stable AA2G — each derivative has a different stability, pH requirement, bioavailability, and skin type suitability. Learn the science before you buy.

Stability Comparison (higher = more stable on shelf)

Pure Vit C (LAA)

Pure Vitamin C

3/10
Ethyl Ascorbic (EAA)

3-O-Ethyl Ascorbic Acid

9/10
Sodium Ascorbyl (SAP)

Stay-C® 50

9/10
Magnesium Ascorbyl (MAP)

VC-PMG

8/10
Ascorbyl Glucoside (AA2G)

Vitamin C Glucoside

10/10
Pure Vit C (LAA)

L-Ascorbic Acid (LAA)

Pure Vitamin C

3

Stability /10

Irritation

High

Bioavail.

10/10

pH Needed

<3.5

Best For

HyperpigmentationPhotoagingCollagen Synthesis

The gold standard of Vitamin C. L-Ascorbic Acid is the most researched and bioavailable form, but also the most unstable. It requires a low pH (below 3.5) to penetrate the skin and work effectively. Best stored in dark, cool conditions and used within 3 months of opening.

5 serums in our DB use this

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Ethyl Ascorbic (EAA)

Ethyl Ascorbic Acid (EAA)

3-O-Ethyl Ascorbic Acid

9

Stability /10

Irritation

Low

Bioavail.

8/10

pH Needed

4.5–6.5

Best For

Sensitive SkinIndian Climate UseBeginnersYear-round use

The best all-rounder Vitamin C derivative for Indian skin. EAA offers exceptional stability even in warm conditions, making it ideal for a country like India where temperatures and humidity are high. It converts to pure Vitamin C upon absorption.

6 serums in our DB use this

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Sodium Ascorbyl (SAP)

Sodium Ascorbyl Phosphate (SAP)

Stay-C® 50

9

Stability /10

Irritation

Very Low

Bioavail.

6/10

pH Needed

5.5–7.0

Best For

Acne-Prone SkinOily SkinSensitive SkinAnti-bacterial benefit

The dermatologist's choice for acne-prone skin. SAP has an added antibacterial property that makes it unique among Vitamin C derivatives — it actually helps fight Cutibacterium acnes (the acne-causing bacteria) while brightening skin simultaneously.

2 serums in our DB use this

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Magnesium Ascorbyl (MAP)

Magnesium Ascorbyl Phosphate (MAP)

VC-PMG

8

Stability /10

Irritation

Very Low

Bioavail.

5/10

pH Needed

6.0–7.0

Best For

Dry SkinSensitive SkinBrightening with HydrationMature Skin

The hydration hero of Vitamin C derivatives. MAP is a water-binding form of Vitamin C that uniquely moisturizes the skin while brightening. It's the gentlest option available and works beautifully for dry and mature skin types.

1 serums in our DB use this

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Ascorbyl Glucoside (AA2G)

Ascorbyl Glucoside (AA2G™)

Vitamin C Glucoside

10

Stability /10

Irritation

None

Bioavail.

4/10

pH Needed

4.0–7.0

Best For

All Skin TypesFirst-time usersSensitive SkinLong-term maintenance

The most stable Vitamin C derivative available. AA2G is formed by bonding Ascorbic Acid with glucose, creating an incredibly stable molecule that resists oxidation under virtually all conditions. The tradeoff is lower bioavailability, requiring enzymatic cleavage by skin glucosidases.

1 serums in our DB use this

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