About:Natural weight loss supplements are made from carefully selected herbs that were tried and tested in the field of weight loss. Because they are natural, they do not contain harmful chemicals that would bring more bad effects than good to the consumer. They will not only make you look good, they will also make you feel good because they will boost your health and energy as well. From the shells of crabs. Chitosan which is derived from Chitin is thought to prevent the absorption of fat by binding the fat molecules to the intestines. Studies have shown that chitosan supplements have led to weight loss but has side effects such as constipation and bloating.