Which type of chemical peel can lead to protein coagulation, resulting in a whitening effect on the skin?

The type of chemical peel that can lead to protein coagulation, resulting in a whitening effect on the skin, is TCA (trichloroacetic acid). TCA is a medium-depth peel that penetrates more deeply into the skin than superficial peels, such as glycolic acid and salicylic acid.

When TCA is applied, it denatures proteins in the dermis and epidermis, causing a coagulation effect. This process results in a visible whitening of the treated area, known as "frosting." This coagulation is beneficial because it helps in the regeneration of new skin cells and promotes collagen synthesis, leading to improved skin texture and appearance over time.

While glycolic and salicylic acids are effective for superficial peeling and target the outer layers of the skin, they do not typically lead to significant protein coagulation. Jessner's solution, although it does cause peeling and has a combination of ingredients, does not produce the same pronounced whitening effect associated with TCA. Thus, TCA is distinctly recognized for its ability to achieve a deeper peel and create a notable whitening effect through protein coagulation.