What are the differences between Salicylic, Lactic, and Glycolic peels?
The Lactic and Glycolic peels are very similar in their actions, but the molecules are slightly different. A good rule of thumb is the pure Lactic is best for treating age/sun spots and the pure Glycolic is best for treating fine lines. The Glyco/Lac combination is great if you are looking for a revitalizing improvement in tone and texture.
Glycolic Acid is the most active and beneficial of the Alpha-Hydroxy-Acids (AHA) in skin care and is made from sugar canes. It is the only AHA which is able to penetrate through the cell walls by virtue of its small molecular size. Once inside the cell, it will trigger new formation of collagenand turn on the synthesis of dermal glycosaminoglycans to plump up the cell and the ground substances in the skin to reduce wrinkles on the skins surface. Glycolic Acid also affects the newly forming keratin cells at the bottom of the stratum corneum causing the bulk of the stratum corneum to lift off and separate from the underlying skin. This gives the skin a much smoother look and feel.
The Lactic acid is a natural humectant which occurs naturally in the skin, and because of this it is able to pull moisture from the air and hold it in the skin. The Lactic acid is less irritating and more moisturizing than the Glycolic, and the Lactic can be used at a slightly higher concentration than the Glycolic, because it is not as irritating.
Salicylic acid is a mild acid that works as a keratolytic agent it encourages the sloughing of dead skin cells. It's a safe, effective treatment for mild acne, oily skin, textural changes and post-inflammatory hyperpigmentation in people of most skin types. Mild acid solutions, such as salicylic acid and glycolic acid, encourage the peeling of the top layer of skin and the opening of plugged follicles, which helps reestablish the normal skin-cell replacement cycle. For milder acne, salicylic acid helps unclog pores to resolve and prevent lesions. It does not have any effect on the production of sebum or the presence of P. acnes bacteria. Like many other topical acne treatments, salicylic acid must be used continuously, even after acne lesions have healed. Its effects stop when you stop using it, so your skin will return to its uneven shedding; pores become clogged, and acne returns.
The Lactic and Salicylic peels complement each other perfectly. The Salicylic is great for acne, but is also drying, and works less well on fading pigmentation. The Lactic acid fades pigmentation and pulls moisture into the skin. So by alternating between the peels you get the benefits of the Salicylic without the excessive dryness, and you get faster improvements to pigmentation and tone.
The biggest difference between the two hydroxyl acids (BHAs and AHAs) is their lipid (oil) solubility. Alpha-Hydroxy Acids (AHAs) are water soluble and Beta-Hydroxy Acids (BHAs) are oil soluble. BHAs are able to penetrate deeper into the pore, which contains sebum and helps to control exfoliation of the dead skin cells that build up inside the pore. Salicylic Acid is the only BHA known for the treatment of acne and acne-prone skin types.