The Ordinary Retinal 0.2% Emulsion Versus Osmosis Beauty Correct Preventative Retinal Serum

Not only does it help exfoliate the skin, it helps strengthen the skin's barrier. When applied, lactic acid helps the skin create ceramides.

Lactic acid is an over-the-counter chemical exfoliant that comes from the fermentation of lactose — a carbohydrate found in milk.

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

Read more about some other popular AHA's here:

This property also makes Pentylene Glycol a great texture enhancer. It can also help thicken or stabilize a product.

Pentylene Glycol also acts as a mild preservative and helps to keep a product microbe-free.

Some people may experience mild eye and skin irritation from Pentylene Glycol. We always recommend speaking with a professional about using this ingredient in your routine.

Pentylene Glycol has a low molecular weight and is part of the 1,2-glycol family.

Studies show retinal may work at a faster rate than retinol due to its structure.

All retinoids have to be converted into retinoic acid before starting to work. Some retinoids take several steps of conversion before binding. Retinal is only one step away, making it more potent.

Like other retinoids, retinal may be irritating. It is best to ease into using this ingredient frequently.

Using the 'ramp up' method, start by using retinol once a week. This gives your skin time to adjust and decrease irritation. Once you feel ready, you can slowly increase the frequency of retinol use.

Using retinoids will increase sun-sensitivity in the first few weeks of use. Though studies show retinoids increase your skin's natural SPF with continuous use, it is best to always wear sunscreen and sun-protection.