Sodium Nitrite, not to be confused of sodium nitrate, is a relatively painless, reliable, and accessible end of life mechanism.
Unlike an Nitrogen Exit bags, Nembutal or opioids, that work on hypoxia (death via lack of oxygen in environment), sodium nitrite just "simply" makes it so your blood doesn't carry oxygen in your blood, even though there's lots in the environment. The SN works by turning hemoglobin into methemoglobin, which can't carry oxygen. This reduces the blood's ability to deliver oxygen to tissues, leading to suffocation even though there's enough oxygen in the air.
The reason people choose it so much is because it ranks 4/5 reliability, 3.5/5 peacefulness, and 5/5 for safety, storage, and legality.
If it doesn't work / you don't ctb, SN has a lot less long term effect potential than other suicide methods.
