Vocabulary:
The Grim Reaper refers to a personification of death in the form of a cloaked skeleton wielding a large scythe.
A side effect is any effect of a drug, chemical, or other medicine that is in addition to its intended effect, especially an effect that is harmful or unpleasant.
A dose is a quantity of a medicine or drug taken or recommended to be taken at a particular time.
The word tolerance refers to a reduced response or diminished sensitivity to a particular substance or stimulus over time, often requiring increased amounts or intensity to achieve the same effects or sensations as initially experienced.
The verb opt means to make a choice from a range of possibilities.
A stimulant is a substance that raises levels of physiological or nervous activity in the body.