You first get a free potion as pat of the Fear and Loathing goal.
The effect of the potion vary, know effects are:
- Gloom Rat Summoned - a Rat appears near you.
- don't waste your precious ingredients crafting this unless Specifically told to craft for a quest. Buy it with reputation points in the market under "Consumables" you should be spending those hearts, as you are capped at 100. Spend spend spend