Exfoliation

Exfoliation when the outer layer of the oldest dead epidermal cells on the surface of the skin are removed to expose fresher cells. Our skin undergoes on a continuous natural exfoliation in cycles of 28 days aprox. This occurs more rapid at a young age.
Usually, exfoliation delivers a tighter, firmer, smoother look and feel of skin. It also allows the better penetration of active ingredients of skin care products.
Should we all exfoliate? How often? What should we use?

The benefits of adding exfoliation to a skin care routine are not universal. Young people generally do not needed it and actually are more likely to suffer its side effects. The opposite side is when someone develop dull, lifeless looking skin because their topmost layer becomes too thick. Exfoliation in this case could be extremely beneficial.
People with excessively oily skin may benefit too, especially if they exfoliate with beta and/or alpha hydroxy acids.
People with dry and/or sensitive skin should not exfoliate or use mild exfoliants infrequently.

How often?

Except for people with extremely oily skin, daily exfoliation is not a good idea. You goal is to remove the dead cells from the skin surface. It takes at least a few days for dead cells to accumulate. If you exfoliate too often, you may be removing too many fresh cells, increasing the chance of irritation and skin damage.
For most people once or twice a week is enough. You should determine optimal frequency based on your skin type, strength of the exfoliants you use, application technique and other factors.
Over-exfoliation triggers an inflammatory response, leading to a compromised lipid barrier that won’t function properly, sensitive skin, and accelerated premature aging. 

Be prudent: listen to your skin, use common sense and inform yourself before trying anything new.
 

What should we use?

There are two types of exfoliants:
Physical exfoliants use friction together with grains or particles to mechanically remove dead skin cells. This can be achieved through a brush, scrubs or any type of hard sponge. It is important for you to know that if you decide to go for a scrub, look for the ones that are “rounded” or you could scratch and irritate your skin due to the pointy edges.

Chemical exfoliants are substances that smooth skin by dissolving the intercellular cement that attach skin cells to the skin’s surface. Chemical exfoliants can also digest the cells as well. Some ingredients like Lactic and Salicylic Acid, Retinol, and enzymes are a few examples of chemical exfoliants.