Don't be afraid to take it as a preventative. Not medical advice, but I've taken it about 5 or 6 times now, over the course of months.

At first I put it on a cracker with honey, but lately I just dispense some on my finger or a butter knife and swallow it down with some water, and then brush my teeth. It's a little bitter but no big deal. The aftertaste doesn't linger and I have had zero ill effects.

I weigh maybe 150 and I take about 1/2" from the tube. I found the measurements confusing on the Duravet plunger but everyone else seems to think it's simple.