· Ultra-Pure USP Grade Formaldehyde Free Methylene Blue· 1 Drop contains 0.5 mg Methylene Blue· 3rd Party Analytical Laboratory Verified Levels of Aluminum (Al), Arsenic (As), Cadmium (Cd), Copper (Cu), Mercury (Hg), Lead (Pb), Selenium (Se), Tin (Sn), Zinc (Zn)· See Photos for Certificates of Analyses· Genuine Biopharm methylene blue items conveniently come with volume markings etched on the glass dropper heat sealed inside the glass bottle.