How often can I apply a 20% Salicylic Acid peel to my face.

Strong salicylic acid peel was such as the 20% strength should be performed under the guidance and followup of a trained medical aesthetician supervised by a physician. Pre-treatment, expert application, and followup treatment including the use of 4% hydroquinone cream and oftentimes a retinoid is part of the expert followup care required for the best results and differs from patient to patient including when to have a secondary peel.

Excellent question.  The answer is never.  20% salicylic acid not for at home use.  It is for professional use and can cause damage in the hands of a novice.  Seek out an experienced, board-certified dermatologist if you'd like to enjoy the benefits of a salicylic acid peel.  A professional knows more than just how to do the peel.  A professional knows whether it is appropriate to do the peel, how to minimize risks, and what to do should you have problem.  

Thank you for your question. I do not recommend using peels on yourself at home, without knowing how they should be used or what skin types and conditions they work best for it can be unsafe to treat yourself. Seek a licensed skin care provider for further treatment options. Peels should not be applied more than once every 4 to 6 weeks depending on the depth. Best Wishes,Pablo Prichard