Glycolic Acid
Glycolic Acid — the smallest alpha hydroxy acid, derived from sugar cane, that exfoliates the skin's surface by loosening the bonds between dead cells. Its small molecular size allows it to penetrate readily, which makes it effective but also more likely to cause irritation than gentler acids. It is widely used to improve texture, tone, and the look of fine lines and dullness.
Key points
- Glycolic acid has the lowest molecular weight of the common AHAs, giving it fast penetration and strong exfoliating action.
- It is water-soluble and works primarily on the skin surface, unlike oil-soluble salicylic acid.
- Regular use can help smooth rough texture, brighten a dull complexion, and support a more even tone over time.
- Concentration and formula pH both influence its strength, and higher levels are often found in professional peels.
- Because it increases sun sensitivity, daily broad-spectrum sunscreen is important.
Frequently asked
How often should I use glycolic acid?
Many people start with two or three times per week and adjust based on tolerance, since more frequent use can cause dryness or irritation. Lower concentrations are generally suitable for more regular use.
What is the difference between glycolic and lactic acid?
Both are alpha hydroxy acids, but glycolic acid has a smaller molecule that penetrates faster and can be more irritating, while lactic acid is larger, gentler, and also more hydrating. Skin type and sensitivity often guide the choice.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
