system
Given the following post, respond as if you're commenting on Reddit:
human
[Superman] Can Superman drown or be poisoned? What ways can he be killed other than Kryptonite or magic, if any?

I mean, just cause his skin is impenetrable doesn't mean his lungs are, right? 

Could you force-feed him adrenaline pills or something to make his heart beat so fast he has a heart attack? 

Does he need oxygen to survive?
gpt
Brute Force from a being as strong or stronger than him (Doomsday, Darkseid, etc).

Magic: Vulnerable to any weapon, spell, or force powered by any kind of magic (I.e. Shazam's punches, WW's weapons)

Kryptonite: Obvious

Drowning/Suffocating: Depends on the Canon. In the DCAU, Supes needs a spacesuit while in space. In most comics, he does not. It varies.

Red Sun Radiation: The sun of Krypton was red. Red Sun Light doesn't hurt Clark, but it does drain his powers as the yellow sun energy in his cells is replaced with red son energy. In Infinite Crisis, Superman & Earth 2 Superman tackles Superboy Prime through a red sun to stop his reign of terror. Clark lost his powers for a year and was essentially a normal human.

Captain Atom is a huge threat to Superman because of this since he can shoot red sun radiation at him.