What makes hyaluronic acid so hydrating? It has the capacity to bind or hold large amounts of water.

Fun fact: It is already naturally found in our bodies, such as the fluids of our eyes and our joints.

Studies find this ingredient to have anti-inflammatory and anti-microbial properties. This can help speed up wound-healing.

Hyaluronic acid can be irritating if the molecule has a low-molecular weight, or if the molecules are small.

One study found low-molecular weight hyaluronic acid to be pro-inflammatory, meaning some people may experience irritation. This is because our bodies use hyaluronic acid in the wound-healing process to signal to our bodies, via irritation, that something needs healing.

The same study found high-molecular weight hyaluronic acid to be anti-inflammatory.

These are some other common types of Hyaluronic Acid:

Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.

Like glycolic acid, it can:

Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.

Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.

To get results, choose products with a pH between 3-4.

Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.

Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.

When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the product’s pH.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.

Read more about some other popular AHA's here:

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Stay hydrated!