Everything contains hydrogen. It is the most abundant element in the universe. However hydrogen is usually bound to other atoms and molecules and therefore not available purely as H2. Just as we don’t get oxygen from H2O, we don’t get H2 from water. This is because H2 and O2 in H2O are not available because they are chemically bound to the water molecule. When used therapeutically hydrogen is dissolved into water in its molecular form, H2.