It can work but it's a really, really painful and slow way to die. And this kind of prevention can work: a lot of suicide prevention is focused on just putting enough barriers in place that it's harder to do on impulse. In the case of the limitation it's probably mostly so that people don't normally have a huge jar of them at home, which is what you get with buying them from costco. How many lives have actually been saved by this is pretty hard to judge though, but I would bet it's non-zero.

On the other hand it's left me without when I really needed it :( I would love to have a huge jar of this. There's so many ways to commit suicide and we can't stop them all.

I think medications in general are too restricted in the EU. Many medications that are really innocent require a doctor's prescription (which when I lived in Ireland cost me 60 euro just for the visit - at least here in Spain it's free to visit the GP).

Assuming the numbers in [1] are correct, the answer to "How many lives have actually been saved by this" is, what, somewhere around 4-5000 (~300 a year for 15 years + some extra)?

More interesting is that it took a long time for it to drop after the legislation was introduced in 1998 - presumably people were still working off their stockpiles?

[1] https://www.statista.com/statistics/471227/death-by-paraceta...