I take capsules (size 00). I buy the herbs in bulk from http://www.mountainroseherbs.com and make my own. I'm not sure of the exact conversion of drops to capsules. I read somewhere that for many herbs, taking 2-4 capsules is equivalent in potency to 40-80 drops.

For Slippery Elm, my herb book recommends taking 1 tsp of the tincture 1x per day to protect against radiation accumulation. I take 2-3 capsules 3x a day - my body tolerates and assimilates herbal remedies very well. I do the same with Feverfew (the book says that Feverfew stimulates the skin, nervous system, reproductive and urinary systems to discharge their poisons). Be sure your bowel is in good working order (2-3 BMs a day) so you can eliminate any poisons quickly.

The radon is worse in winter when the house is closed up. During the warmer months, we open all the windows and the back door during the day and evening to vent the house (we work from home).

I hope this information helps. Prevention is the best medicine.