It requires no special magical preparation and consists only of alcohol, milk and crow's eggs making it easy for fighters to brew their own batches. Many taverns and guild halls catering to warriors will usually have a few bottles for sale stashed away.
The concoction provides an immediate powerful boost to the person's aggression and strength that lasts for 1D4 hours (give or take a few hours depending on the person's endurance and/or capacity for alcohol).
Once the bonus has worn off however, it comes with a terrible hangover that lasts anywhere up to a whole day (2D10 hour) where in the person is barely functional and comes with massive penalties to almost ALL rolls. A failure of any role during this time is accompanied by a bout of projectile vomiting lasting D6 minutes in which the character cannot perform any actions whatsoever.