I happen to love freshly exfoliated skin. The softness, smoothness and evenness of my skin after an exfoliation treatment always leaves me wanting more. However, giving in to my desires may do more harm than good since darker skin is prone to hyperpigmentation if it experiences trauma. And let’s face it, exfoliation is, by nature, trauma to the skin.MORE: Are You OD’ing on Skincare Products?So how do you know when you need to exfoliate and what are your best options?Our skin gives telltale signs when it needs exfoliation. If your skin is lackluster and feels dry to the touch, then it may be time to slough off dead skin cells. If you’re acne prone skin is no longer responding to your skincare regimen, then consider exfoliation. If your skin just feels like it needs a little pick-me-up, then exfoliate! There are many exfoliation products on the market, but they all revolve around two types of exfoliation: physical and chemical.COLUMN: Beating the Winter Skin BluesPhysical exfoliation is the mechanical process of removing surface dead skin. The abrasive or exfoliant forces the worn surface cells back and forth (and side to side), loosening up the grip of the intercellular cement—the adhesive made of oils and proteins that keep cells stuck together—eventually allowing the cell to break free. Physical exfoliants can be synthetic, such as polyethylene, or as natural as strawberry seeds. They can be very hard and unforgiving, such as aluminum oxide crystals used for microdermabrasion, or soft like jojoba butter beads that melt on the skin. The downside to physical exfoliants is that many have edges that could potentially cause microcuts on the skin, damaging the protective barrier.MORE: DIY Beauty RecipesOther physical exfoliants include pumice, sodium bicarbonate, loofah, walnut shells, apricot shells, coconut hull, polyethylene, sugar, salt, amber powder, diamond powder and polylactic acid.Chemical exfoliation can be achieved with enzymes or acids. Enzymes used for exfoliation are a class of proteins known as proteolytic enzymes. Their sole existence is to breakdown long chain proteins into shorter portions. They are effective and gentle for cutting through the “cement” holding old cells in place on the surface of the skin.There are different types of enzymes commonly used in skin care products. Food-based enzymes, such as bromelain, which is extracted from pineapple, and papain from unripe papayas (it’s also the main ingredient in meat tenderizer) are popular. Pomegranate and pumpkin enzymes also have wonderful topical benefits. Other protein-digesting enzymes used in skin care include protease, lipase and subtilisin.Acids, most commonly alpha hydroxy acids (AHAs) and beta hydroxy acids (BHA), are widely-used chemical exfoliants. These acids work faster than enzymes, which can make them more irritating. Acids are used in professional-strength chemical peels administered by skincare professionals, as well as in skincare products for at-home use. AHAs such as glycolic acid, lactic acid and citric acid have wonderful anti-aging benefits to help moisturize, reduce fine lines and wrinkles and even out skin tone. BHAs are best suited for oily and acne-prone skin to reduce acne flare-ups and unclog pores. You can identify AHA products by checking the label for the following acids: glycolic, lactic, citric, malic, tartaric and mandelic. Beta hydroxy acid usually refers only to salicylic acid.MORE: The Seven Habits of Women With Great SkinWhichever exfoliation method you choose, use it wisely and you won’t be disappointed!