### Instruction: What is the difference between retinol and tretinoin?
### Response: Everyone’s skin is different, but no one’s skin is immune to the effects of sunlight, stress, and natural aging. To treat these effects, you might decide to use retinoids.

Retinoids are chemical compounds related to vitamin A.

Retinol and tretinoin are both examples of retinoids. Tretinoin can also be called all-trans retinoic acid (ATRA).

When it comes to treating your skin, the biggest difference between these two compounds is their strength.

Retinol is a vital nutrient. It’s fat-soluble, which means it can stay in your body for a long time. Your liver can take this stored retinol and convert it into tretinoin. Your body will use the tretinoin for a variety of biological functions.

For the purposes of skin care, tretinoin can be thought of as a more concentrated version of retinol. This means that tretinoin is stronger than retinol.