I have been on 50-100 mg of Iodine for a couple of years and there is only fragments left of my hypo T condition I once had. If you take companions like selenium, vit C, magnesium , salt and vit B you should be safe.
7 drops is approx 45 mg of iodine, many percents over the 750 mcg you have read about. Dont worry; there is a lot of bad press about iodine.
Go for the info here at the forum, or / and from the docs that do this for their living; like dr. Brownstein, Derry, Abraham etc.