Yes, Matter is NSF Certified for Sport. Elysium Health third-party tests every lot of Matter for purity and quality. NSF International additionally tests every lot to confirm that products bearing its seal do not contain unsafe levels of contaminants, prohibited substances or masking agents, and that what is on the label matches what is in the product. Learn more about what it means to be NSF for Sport Certified here: https://www.nsfsport.com/our-mark.php