The primary reason people don't get any results is a quality issue. The supplement industry is not regulated like the pharmaceutical. Companies are not required to analyse the content of their products. If they were, they would reject up to 30% of their raw materials due to contamination, heavy metals, etc.
You should select a product that has a number of published papers and studies to document its safety and efficacy. Then can you experience satisfying results.
Feel free to e-mail me to receive suggestions.
Stephan