As a humectant, it helps the skin stay hydrated by pulling moisture to your skin. The low molecular weight of glycerin allows it to pull moisture into the deeper layers of your skin.

Hydrated skin improves your skin barrier; Your skin barrier helps protect against irritants and bacteria.

Glycerin has also been found to have antimicrobial and antiviral properties. Due to these properties, glycerin is often used in wound and burn treatments.

In cosmetics, glycerin is usually derived from plants such as soybean or palm. However, it can also be sourced from animals, such as tallow or animal fat.

This ingredient is organic, colorless, odorless, and non-toxic.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

Besides anti-aging, this ingredient also helps with skin brightening and soothing.

The most effective forms of resveratrol are isobutyrate and butyrate. These have the strongest effect on increasing A1 collagen and reducing inflammation.

A note on it being a retinoid alternative:
Despite it's amazing skin benefits, it is not a replacement for retinoids. However, it is recommended for people with sensitive skin or intolerance to retinoids.

Resveratrol is naturally found in grapes, peanuts, and berries.