Natural products and supplements aren't regulated by the FDA and can contain any levels of fillers and impurities in them while claiming to be high quality. The best way to know if your supplement is pure is to research the company and it's quality standards.
1. Bio Available- Is your supplement bio available, meaning does it break down in your body in a form that you can use? Try putting your supplement in water to see if it dissolves. If it doesn't dissolve, then it's not bio available.
2. Safety and Potency- Does the company manufactures their own products? 85% of brands don't make or test their products. These sellers aren't responsible for their quality.
3. Testing- What tests do they run on your supplements to check for quality and purity? Are they transparent about testing and results? Do they have their own laboratory and scientific team? Are their products also tested by a third party company?
doTERRA and Nature's Sunshine ensure quality, run 600 quality tests for potency, herbal content and cleanliness. They grow crops around the world in their natural habitat and visit their facilities around the world to see first hand their manufacturing practices and make sure the manufacturer has good sustainability. They research and test for potency based on climate, time harvested and natural habitat.
These companies are so committed to quality they would rather not offer a product than sell something that is poor quality. This is why they are my top choice of supplements and natural products!
The best test is they work and you see the results. You can't change peoples lives with average products.