You activate a buff by double-clicking on it in your Inventory, and then choosing the Eat or Use from the radial menu, or by dragging the item onto your toolbar and hitting the corresponding Function key.
It' s very important to note that you can only use a limited number of buffs at any one time. On your Character Sheet (CTRL+ C keys), you' ll see Food and Drink bars. (NOTE: When the Food bar is full, you can no longer consume food buffs; likewise for the Drink bar.)
<< Chapter | < Section | Table Of Contents | Section > | Chapter >>