Hi I have the same problem

I have the same problem my skin has gone darker than my usual colour and I have been using be treatment for a month now

Skin darkening in the beginning is almost always due to overly dry skin. Please try these tips. http://www.acne.org/faq.html#dry

Please also read the blue box on this page: http://www.acne.org/faq.html#burn

If these tips do not help and the darkening is bothersome to you, you may need to discontinue or see your dermatologist for advice.