What Is Benzilic Acid?
Benzilic acid, scientifically known as hydroxydiphenylacetic acid, is an organic compound made of two linked benzene rings, a carboxylic acid group and a hydroxyl group. This balanced mix of acidic and slightly alkaline parts lets it act as a gentle pH adjuster in skincare formulas. It does not usually come from plants or animals; instead it is created in the lab by converting another compound called benzil through a reaction discovered by the chemist Justus von Liebig in the 1800s. Over time manufacturers found that this stable, white crystalline powder could help keep creams and lotions at a skin-friendly pH level, so it moved from the chemistry bench into the cosmetics lab. Today you may spot benzilic acid in moisturizers, clay or cream masks, soothing lotions, anti-aging serums and specialty treatments that need precise pH balance to remain effective and comfortable on the skin.
Benzilic Acid’s Cosmetic Benefits/Uses
In topical products benzilic acid serves one main purpose that brings clear advantages to both formulators and users.
Buffering: Benzilic acid helps keep the final product at a stable, skin-compatible pH. A well-buffered formula feels more comfortable, supports the skin’s natural barrier and protects delicate active ingredients from breaking down too quickly, which can improve shelf life and performance.
Who Can Use Benzilic Acid
Because it is used mainly as a mild pH buffer, benzilic acid suits most skin types including normal, dry, oily and combination skin. Sensitive skin generally handles it well at the low levels found in finished formulas, though anyone with open cuts or severe irritation may feel a brief sting.
Production is fully synthetic, with no animal-derived inputs, so products containing benzilic acid align with vegan and vegetarian preferences.
No evidence suggests special risks for people who are pregnant or breastfeeding when the ingredient is used in standard cosmetic amounts. This is not medical advice and anyone who is pregnant or nursing should ask a doctor before using new skincare products.
Benzilic acid does not cause photosensitivity, so it can be worn during the day without extra sun precautions beyond regular sunscreen.
Potential Side Effects/Adverse Reactions
Reactions to topical benzilic acid differ from person to person. The points below list potential side effects that could occur even though most users experience none when the ingredient is formulated correctly.
- Mild stinging or burning especially on freshly shaved, broken or highly sensitive skin
- Temporary redness or irritation if the formula’s pH is still slightly outside an individual’s comfort range
- Allergic contact dermatitis in those with a specific allergy to the compound, which is rare
- Eye irritation if the product accidentally gets into the eyes
If any of these effects appear and persist stop using the product and consult a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0 / 5
Benzilic acid is used at very low concentrations purely as a buffering agent, has no oily or waxy characteristics and does not linger on the skin in a way that could block pores. For these reasons formulators consider it non-comedogenic.
Suitable for acne-prone and breakout-prone skin.
No additional concerns related to pore clogging have been reported in the scientific or formulating community.
Summary
Benzilic acid’s main job in skincare is simple: it keeps a formula’s pH steady so active ingredients stay effective and the product feels comfortable on the skin. It does this by balancing small shifts toward acidity or alkalinity, acting like a cushion that absorbs pH swings.
The ingredient is something of a behind-the-scenes helper. Chemists know it well, yet it is not a headline act on product labels, so most consumers have never heard of it. Even so, its reliability keeps it in steady use where precise pH control is needed.
Safety data show a low risk profile when used at cosmetic levels. Most users tolerate it without issue, though everyone’s skin is unique. Whenever you pick up a new formulation that lists benzilic acid, do a quick patch test first to make sure your skin agrees with the overall product.