I wouldn't take very much of it if your just feeling run down. Just the thought of it used to make me shudder. You should just work up to a maintenance dose once a day. I still occasionally take 3 drops for allergies. Works when all else fails.
The best way for me to take it was with distilled water. I plug my nose and the only thing I can taste is the lime acid. Then I chase it down with more water. They say fresh pineapple is good but if you mix it with anything it might get weaker so I don't.
If you get up to the higher doses you have to dilute it down or the PPM may be to high for your stomach.