Alpha Hydroxy Acids (AHAs) Skincare Review

Flashcards covering key definitions, molecular weights, functions, and skin benefits of AHAs (Glycolic, Lactic, and Mandelic acids).

What are Alpha Hydroxy Acids (AHAs) and where do they primarily work in the skin?

They are water-soluble exfoliating acids that dissolve in water and primarily work within the skin's water-rich layers.

How do glycolic, lactic, and mandelic acids compare in terms of molecular size?

Glycolic acid is the smallest molecule, lactic acid is the middle size, and mandelic acid is the largest molecule.

What are the primary characteristics and skin benefits of glycolic acid?

Glycolic acid is the smallest and most potent AHA, penetrates the deepest, supports the dermis, and is best for aging.

What is lactic acid derived from and what primary benefit does it offer?

Lactic acid is derived from milk and helps mostly with brightening.

What is the molecular weight of lactic acid and what dual action does it perform on the skin?

Lactic acid has a molecular weight of $90$. It functions both as a chemical exfoliant (breaking down corneodesmosomes) and as a great hydrating humectant.

What are the three sequential steps of lactic acid's action on the skin?

1. Penetrates Stratum Corneum.
2. Loosens desmosomes between corneocytes.
3. Allows dead surface cells to shed more easily.

How do Natural Moisturizing Factors (NMFs) function when stimulated by lactic acid?

NMFs are small molecules acting like a built-in hydration system that attract and hold water to keep the Stratum Corneum hydrated and plump.

What is the molecular weight of mandelic acid and what was it originally derived from?

Mandelic acid has a molecular weight of $152\,g/mol$ and was originally derived from bitter almonds.

Why is mandelic acid considered the gentlest AHA and recommended for sensitive skin?

It has a relatively large molecular weight and the slowest penetration speed out of all AHAs commonly used in skincare.

How does mandelic acid exfoliate the skin and treat hyperpigmentation?

It weakens the bonds holding dead skin cells together to shed evenly through desquamation, prevents clogged pores, and accelerates cell turnover to gradually fade hyperpigmentation.

What additional properties make mandelic acid particularly beneficial for congestion and acne-prone skin?

It has antibacterial and anti-inflammatory properties.