Re: the nitty gritty....

I only know about Sciencecompany, and their Reagent is more pure than USP, and is quite good for ingestion. Many users are on this forum.

If you go with a different company, search their site to see how their opinion of grades run and how what they are calling their Lugol's compares with that. . As in my prior post, the Sciencecompany Regeant is between USP and ACS.

Please note that the FDA is really hard on those who sell iodine. So. since they are a 'Science company", they cannot advertise the health benefits of Lugol's.

Be assured, their Reagent is more pure than USP. Again, here are the top three of the grades:

Chemical Grade Definitions
Chemical grade definitions from highest to lowest purity...
1. A.C.S.

A chemical grade of highest purity and meets or exceeds purity standards set by American Chemical Society (ACS).

2. Reagent

High purity generally equal to A.C.S. grade and suitable for use in many laboratory and analytical applications.

3. U.S.P.

A chemical grade of sufficient purity to meet or exceed requirements of the U.S. Pharmacopeia (USP); acceptable for food, drug, or medicinal use; may be used for most laboratory purposes.

There is a lower grade called lab, which is not what this company sells. They sell the second highest grade.