Does Herbal Medicine affect Pokemon with a certain nature?

Question

All Herbal Medicine tastes bitter has the secondary effect of lowering a Pokemon's happiness. However, what if I use one on a Pokemon with, say, a Calm nature? A Calm nature boosts Special Defense, so the food it likes is bitter. Will its happiness be affected or not?

Answer 1

Yes it still will be effected, nature and taste have nothing to do with it. Happiness will be lowered.

Answer 2

No.
Herbs will always lower happiness, even if your Pokemon LOVES bitter foods.