We have finally fully implemented our unique serial numbers on all our Injectable products. If your product does not have a serial number or the serial number does not verify in our system please contact us immediately at Lab@Syntrop.com and let us know where you purchased this product from. The serial number is four sets of 4 alpha numeric characters separated by dashes for easy input. Our tablets will soon have the same security features for your satisfaction that you are purchasing authentic Syntrop products.