Over 6 years ago when I began my Iodine journey I started out painting iodine.
I experimented with Lugols a little later and hated it.
I like elemental Iodine set in drinking alcohol like Everclear or golden grain.
You could take nascent or magnascent too start but they are pricey..
Although I recently experimented
with selenium with yeast I have gone back to my yeast free selenomethionine that I have used for years. "Now" brand is a favorite too many.
Make sure you take 200 micrograms of selenomethionine each and every day as you paint or take the elemental Iodine internally. Take baby steps if need be and skip days sometime as you may need.
Your body will adapt... as you get to higher doses.
P.S. I just recently took over a 100 milligrams of SSKI and tolerated it well.
But I also took way over 500 milligrams of elemental iodine years ago for almost 2 months everyday and it cured my stomach ulcers. I took almost
800 mcg's of selenomethionine in divided doses at the same time.