Medium depth peels can reach the next layer of the skin,
the dermis, and therefore can have more profound effects. Trichloroacetic acid (TCA) is a utilized for medium depth to
deep peels, based upon concentration of the acid. Unlike
glycolic acid, TCA does not require neutralization, but its effects
are seen by ‘frosting’ the skin, turning it slightly white as the
keratin in the skin is coagulated. A combination of various
superficial peels, such as Jessner’s solution and TCA, layered
together is another manner of achieving a medium depth peel.
In general, medium depth peels result in a bit more downtime,
and redness can be expected for a week to ten days, with mild discomfort for a day or two. Because of the more vigorous action
of this subset of peels, they offer more dramatic results than the superficial peels in terms of smoothing the texture of the skin, eliminating wrinkles, and evening out skin tones.

Deep peels have fallen out of favor due to the risk-benefit
profile, concerns about scarring, and also due in large part to
the evolution of other more predictable ablative techniques,
such as laser treatments.