Ultimate Serum's products contain naturally occurring elements that are included on the Prop 65 list of substances that require a warning. The occurrence of these elements is to be expected and the result of the presence of these naturally occurring elements in the environment. The extreme standards of Prop 65 have resulted in warnings appearing on an increasing number of natural supplements whose levels of naturally occurring metals do not meet the Prop 65 standards. Levels of metals or chemicals that are known to the State of California to cause cancer would have to exceed the prop 65 standards by more than 1,000x before there is an observable effect on the rate of birth defects. We test our products for quality and purity and we stand behind every product we sell. We are constantly working to ensure that our products are the best available and meet the standards of our amazing customers.