Alpha Hydroxy Acid (AHA)

History

Alpha Hydroxy Acids (AHAs) have been used in beauty practices for centuries. Ancient Egyptians are believed to have used sour milk, a natural source of lactic acid, while other civilizations applied fruit and sugar-based ingredients to improve the appearance of the skin.

Modern research into AHAs expanded during the 1970s and 1980s, when dermatologists and cosmetic scientists began studying their ability to exfoliate the skin and improve the appearance of uneven texture. Today, AHAs are among the most widely used ingredients in professional and consumer skincare products.

Source

Alpha Hydroxy Acids (AHAs) are a family of water-soluble acids naturally found in fruits, milk, and sugar cane. They can also be produced synthetically for cosmetic formulations to ensure consistent purity and performance.

Common AHAs include:

  • Glycolic Acid (from sugar cane)

  • Lactic Acid (from fermented sugars or milk)

  • Citric Acid (from citrus fruits)

  • Malic Acid (from apples)

  • Tartaric Acid (from grapes)

  • Mandelic Acid (from bitter almonds)

Common INCI Names

  • Glycolic Acid

  • Lactic Acid

  • Mandelic Acid

  • Citric Acid

  • Malic Acid

  • Tartaric Acid

Cosmetic Uses

AHAs are primarily used to exfoliate the outermost layer of the skin, helping reveal a smoother, brighter-looking complexion.

Common cosmetic uses include:

  • Facial exfoliants

  • Anti-aging creams

  • Facial serums

  • Chemical exfoliants

  • Toners

  • Brightening treatments

  • Moisturizers

  • Cleansing pads

  • Face masks

  • Neck creams

  • Hand creams

  • Body lotions

  • Body exfoliants

  • Foot care products

  • Professional chemical peels

AHAs are often included in products designed to improve the appearance of dullness, uneven skin texture, and visible signs of aging.

Texture

AHAs themselves are typically colorless, water-soluble ingredients.

When formulated into cosmetics, products may feel:

  • Lightweight

  • Smooth

  • Fast absorbing

  • Refreshing

  • Non-greasy

  • Liquid or gel-like

  • Creamy (in moisturizers)

Many AHA products provide a silky finish while allowing other moisturizing ingredients to soften the skin.

Stability

AHAs remain most effective when formulated at an appropriate pH and stored correctly.

Typical Shelf Life

  • Usually 18–36 months unopened

  • Follow the product's recommended Period After Opening (PAO) once opened

Storage Recommendations

  • Store in a cool, dry place

  • Keep containers tightly closed

  • Protect from excessive heat and direct sunlight

  • Avoid contamination during use

Proper packaging helps maintain ingredient stability and product performance.

Frequently Used With

AHAs are commonly combined with:

Hydrating Ingredients

  • Hyaluronic Acid

  • Glycerin

  • Aloe Vera

  • Panthenol

  • Betaine

Moisturizing Ingredients

  • Jojoba Oil

  • Argan Oil

  • Squalane

  • Shea Butter

  • Ceramides

Skin Conditioning Ingredients

  • Niacinamide*

  • Allantoin

  • Green Tea Extract

  • Chamomile

  • Oat Extract

  • Calendula

Cosmetic Ingredients

  • Emulsifying Wax

  • Cetyl Alcohol

  • Cetearyl Alcohol

  • Xanthan Gum

*Some formulations separate AHAs and niacinamide because they perform best at different pH ranges, while others successfully combine them using carefully balanced formulations.

Common Products

AHAs are commonly found in:

  • Facial cleansers

  • Exfoliating toners

  • Facial serums

  • Night creams

  • Anti-aging creams

  • Moisturizers

  • Face masks

  • Peeling gels

  • Chemical exfoliants

  • Brightening treatments

  • Neck creams

  • Body lotions

  • Body exfoliants

  • Foot creams

  • Hand creams

  • Professional chemical peels

Frequently Asked Questions

What are Alpha Hydroxy Acids (AHAs)?

Alpha Hydroxy Acids are water-soluble acids used in skincare products to exfoliate the surface of the skin and improve the appearance of texture, brightness, and overall skin smoothness.

What is the difference between AHAs and BHAs?

AHAs are water-soluble and primarily exfoliate the skin's surface. Beta Hydroxy Acids (BHAs), such as salicylic acid, are oil-soluble and can penetrate into pores, making them popular in products for oily and blemish-prone skin.

Which AHA is the strongest?

Glycolic Acid is generally considered the most penetrating AHA because it has the smallest molecular size among the commonly used Alpha Hydroxy Acids.

Which AHA is the gentlest?

Mandelic Acid and Lactic Acid are often considered gentler options because their larger molecular size generally results in slower penetration than Glycolic Acid.

Can AHAs be used every day?

Some lower-strength AHA products are formulated for daily use, while higher-strength products may be intended for less frequent application. Always follow the manufacturer's directions.

Are AHAs suitable for sensitive skin?

Some individuals with sensitive skin may prefer lower concentrations or gentler AHAs such as Lactic Acid or Mandelic Acid. Because skin tolerance varies, patch testing is recommended.

Should I wear sunscreen when using AHAs?

Yes. AHAs can increase the skin's sensitivity to sunlight. Using a broad-spectrum sunscreen during the day is recommended while using AHA-containing products.

Can AHAs be used with Hyaluronic Acid?

Yes. Hyaluronic Acid is frequently paired with AHAs because it helps support skin hydration after exfoliation.

Can AHAs be combined with Retinol?

Some products combine AHAs and retinoids, but these ingredients can be irritating for some people when used together. Follow product directions or consult a skincare professional if unsure.

Are AHAs natural?

Many AHAs occur naturally in fruits, sugar cane, and fermented ingredients. Cosmetic-grade AHAs may also be produced synthetically to provide consistent purity, quality, and performance.

Do AHAs help improve the appearance of fine lines?

AHAs are commonly used in products designed to improve the appearance of fine lines, uneven texture, dullness, and smoother-looking skin through surface exfoliation.

Are AHAs used only on the face?

No. AHAs are also used in body lotions, hand creams, foot care products, and exfoliating treatments designed for rough or dry areas of the body.