Since each potency measure relies on different standards and techniques, and since there can be considerable variability among biological materials, it can be difficult to draw parallels between the dosing used for different units of potency.
Converting between different potency values will typically require more knowledge about how the product was manufactured. Often times, PNU assessments are performed during the manufacture of w/v products. If it becomes necessary to switch between PNU and w/v products, ALK may be able to provide information to help with that conversion. However, even with this information, caution should be exercised when switching to any new vial of extract.