Citric Acid
A natural pH adjuster and mild antioxidant. Citric Acid, derived from citrus fruits or fermentation, is widely used in skincare to help balance pH, improve formula stability, and provide gentle exfoliation.
Where Does Citric Acid Come From?
Originally isolated from lemons in Europe during the late 1700s, Citric Acid is now primarily produced through fermentation of sugars using Aspergillus niger. It remains one of the most common naturally derived acids used in cosmetics.
Citric Acid vs. Sodium Citrate
| Feature | Citric Acid | Sodium Citrate |
|---|---|---|
| Primary Role | pH adjuster, mild antioxidant, exfoliant | Buffer, stabilizer for actives |
| Skin Feel | May tingle at higher concentrations | Neutral, comfort-preserving |
| Best For | Exfoliating cleansers, serums, toners | Vitamin C systems, actives requiring pH balance |
| pH Range | 3.0–6.0 | 5.0–7.0 |
| Source | Fermentation of citrus sugars | Neutralized citric acid (fermentation-based) |
Why Is Citric Acid Used in Skincare?
- pH Adjuster – Ensures formula stability and skin compatibility.
- Antioxidant Activity – Helps neutralize free radicals in blends.
- Exfoliation – At higher levels, works as a mild AHA for smoother skin.
Best Paired With
- Vitamin C Serums – Enhances stability of ascorbic acid systems.
- Sodium Citrate – Acts together as a buffering duo for active serums.
- Gentle Surfactants – Keeps pH balanced in cleansers.
Fun Facts About Citric Acid
Fun Fact #1
First isolated from lemon juice in 1784 by Carl Wilhelm Scheele.
Fun Fact #2
Today, over 90% of citric acid is produced via fermentation, not fruit pressing.
Fun Fact #3
It belongs to the AHA (alpha-hydroxy acid) family, like glycolic and lactic acid.
Final Thoughts
Citric Acid is a versatile skincare ingredient that ensures pH stability, adds antioxidant protection, and can even provide mild exfoliation. It’s a quiet workhorse that keeps active formulas balanced and effective.
