Are the consequences of this Magic drug balanced with its benefits?

I’m planning to have my players deal with a drug ring in a city with a prominent magic university. I wanted to have a drug that would make sense as a drug to be a problem in this particular city and be tempting for my players to use it, but still have potentially serious consequences.


Majup

Taking a hit as a free object interaction when you cast a spell allows you to ‘upcast’ spells without expending higher spell slots. As an example, this would mean if you take a single hit of Majup then cast the spell Fireball at 4th Level, you will only expend a 3rd level spell slot. If you take two hits at once, you can cast the spell at 6th level while expending a 4th level spell slot. This does not allow you to cast a spell while using a spell slot lower than the spells original level. When you take a hit of Majup, roll an addiction saving throw (Constitution) of DC 8 + (3 times the number of hits taken). On a failure, gain a stage further of addiction. When addicted, if you have not taken a hit of Majup since the previous dawn, make a withdrawal saving throw (Constitution), and consult the chart below for the result, as well as an additional effect based on your stage of addiction:

Saving Throw Result 0-5 6-10 11-15 16-20 21+
Minor Addiction – You have a minor tremble in your hands You gain a point of exhaustion, but still gain all other effects from the long rest No Negative Effects Overcome your addiction Overcome your addiction Overcome your addiction
Moderate Addiction – Above, plus whenever you cast a spell that has additional effects when cast at higher levels and don’t chose to take a hit, you must make a DC 10 Wisdom saving throw, or you take a hit of Majup provided you have some before casting the spell You gain no benefits from this long rest, and gain a point of exhaustion You gain a point of exhaustion, but still gain all other effects from the long rest No negative effects Your Addiction becomes Minor Overcome your addiction
Major Addiction – above, plus You need to make a withdrawal saving throw every 8 hours; and the above wisdom saving throw is a DC 15 You gain no benefits from this long rest, and gain a point of exhaustion You gain no benefits from this long rest, and gain a point of exhaustion You gain a point of exhaustion, but still gain all other effects from the long rest No Negative Effects Your Addiction becomes Moderate
Crippling Addiction – Above, plus You need to make a withdrawal saving throw if you have not taken a hit in the past 4 hours, and the above wisdom saving throw is a DC 20 Your withdrawals Overwhelm you; you are at zero hit points, and need to make death saving throws You gain no benefits from this long rest, and gain a point of exhaustion You gain no benefits from this long rest, and gain a point of exhaustion You gain a point of exhaustion, but still gain all other effects from the long rest No Negative Effects

You can remove a single level of addiction with a Lesser Restoration once per day. A Greater Restoration can completely cure the addiction.


Does this appear balanced? Are the benefits worth the potential consequences? I feel the benefits might be a bit weak, is there another benefit that might make sense thematically? Is there anything else I would need to consider before putting this in the campaign?