Karrak

A powerful painkiller, karrak allows creatures to continue through the most grievous injuries. As an action, you can apply this substance to a creature within 5 feet. For the next 10 minutes, the creature experiences a high that allows them to roll an additional d8 when making an ability check or saving throw using Constitution, and at the start of each of the creature's turns it gains 2d8 temporary hit points. At the end of the high, the creature must succeed on a DC 20 Wisdom saving throw or experience a low that lasts 4 hours, during which they must roll a d8 and subtract the result when making an ability check or saving throw using Constitution, and for the duration their current and maximum hit points are reduced by 2d8. If this would reduce your maximum hit points below 1, it instead becomes 1. At the end of the low, the creature must make a DC 20 Constitution saving throw to resist addiction.