This product is now offered at 500ug & the new formula will be a tablet that dissolves under the tongue (sublingual) This change is to reflect our observation that there is widespread deficiency of vitamin B12 for many reasons & at least 500ug is needed to help address this problem. As B vitamin are water soluble, the higher level is not a problem for those who have a lower need but a lower level is insufficient for the any people who are B12 deficient. The new sublingual delivery is to help ensure maximum uptake of this nutrient which can be absorbed into the blood stream by the blood vessels under the tongue. The price is the same as it was for the lower potency.