obagi clear

Okay, so Obagi Clear's active ingredient is hydroquinone 4%. And, you need a prescription to get it, right? So how does one go about trying obagi and getting the obagi clear, blender, tretinoin, and sunfader? There's quite a few online shops that carry them, but just want to cautious about this, ummm, must be a reason why obagi clear is not over-the-counter. here's a site with more info on obagi skin care, and the rest.