I was given one of these a few years ago as a gift and opened it up just to see what an "energy nugget" was. It was a Tootsie Roll.

There is an old Chinese stand-up comedy (xiangsheng) routine -- now banned for being too risque for public performance -- that kind of relates to this:

An old man takes sick with a rare disease. The doctor tells him “This is a serious illness, my friend, but we can cure it for you. There’s a special Chinese herbal medicine that will fix you right up. But there is one problem: the prescription requires that you drink milk with it.”

“Why, that’s no problem.” the old man says.

“HUMAN milk,” clarifies the doctor.

“Well, that’s no problem either. It just so happens my daughter-in-law just gave birth to a baby. I can just get some milk from her.”

“Sorry, but there’s one more requirement,” says the doctor. “The milk has to be drunk directly from the breast, otherwise it loses its effectiveness.” Whew. This might be a little tricky. What can he do? The old man has no choice but to directly approach the daughter-in-law with his problem. He explains his predicament to her, and she is quite understanding.

“It’s a matter of life-and-death,” she says. “Of course I’ll help you.” So she timidly opens up her blouse and lets the old man suck the milk. But he has barely had one mouthful when the son — who had heard that his father was ill — returns home from work early. Opening the door and seeing his young wife there with his very own father in this rather compromising situation, he is understandably pretty pissed off.

“Dad!” the son cries in shock. “What the hell are you doing?” The father, seeing his son’s displeasure, stands up indignantly and says, “So! I drink one mouthful of your wife’s milk and you get this upset? Have you forgotten how much of MY wife’s milk YOU drank when you were a baby?”

(From http://www.danwei.org/tv/stifled_laughter_how_the_commu.php)