The product could have too high of a dose. Aslo you should make sure you have no heart problems,blood presure problems or any other illnesses before taking such products.
Im also not sure what you trying to achieve with this product-if your wanting to have more regular bowel movements then try something gentler like some oils,a bit of inner gel aloe vera juice or even some fresh sqeezed orange juice-around 750ml with provide a laxative effect. Also dont forget to drink moderate amounts of water and moderate exercise.
Fibre helps some people and it makes some peoples constipation worse,it depends on the situation.
If your already going to the toilet 1-2 times a day then you shouldnt take any laxative like senna etc as your bowels are already good and overuse of laxatives can sometimes cause G. I problems and make your bowels ineffective to work on their own well.