I see your point. However, it's a misrepresentation. I looked on the J Crow's site to see how they describe it. They say one drop of 2% is slightly less than 1/2 the amount of one drop of 5%. However, it's really 40%, not slightly less than 50%.
Example -- 2% times 100 = 0.02. 5% times 100 = 0.05.
0.02 divided by 0.05 = 0.40 = 40%.
40% will never be "slightly less than half" in my book.
Then Swanson's says "approximately 3.125 mg," which is putting numbers to what J Crow's vaguely referred to. 3.125 mg is 50% of 6.25 mg, then they plug in "approximately." It's a way to make it seem that you're getting more value than you really are.
Calculating Number of MG's of Iodine and Potassium Iodide per Drop of Lugol's Solution:
LUGOL'S 5%: Each VERTICAL drop is about 6.25 mg's of iodine/potassium iodide (2.5 mg iodine, 3.75 mg potassium iodide) and 2 drops is about 12.50 mg's of iodine/potassium iodide (5.0 mg iodine, 7.50 mg potassium iodide). Compared to other's, J.CROW'S® Lugol's Solution offers big savings.
LUGOL'S 2%: Slightly less than 1/2 half the above measurements.