Acne is a complicated skin condition with no one-stop solution and so Silver Serum will not always work for everyone. However there are some common mistakes people make that can reduce the effectiveness of Silver Serum. The most common problem is people using other anti-bacterial products (washes, cleansers etc) at the same time or in conjunction with Silver Serum. Silver Serum works by only killing off bad skin bacteria and, more essentially, preserving good skin bacteria which is what helps to build up stronger and more resilient skin. If you're using an anti-bacterial agent at the same time as Silver Serum you will be reducing it's effectiveness. Another common problem is not cleansing before using Silver Serum. If the skin is already teaming with old bad skin bacteria, then Silver Serum is going to be out numbered. Clean the skin first with a non-anti-bacterial cleanser or wash before applying Silver Serum, and it should be much more effective.