I have never understood how ld50 is very confidence inducing? has the medical profession ever considered raising that standard?

The : The ld50, which is the dose of a substance that will result in death of 50% of the people who take it, is not really a medical term. It is a term from the science of toxicology. In medical use, it is a way judging the relative safety of a medication. Generally, a physician would want to prescribe a medication with a therapeutic dose that was as much lower than its ld50 as possible.. Most substances, even water, can kill people if taken at a high enough dose. The ld50 is simply a way of looking at the relative safety, or danger, of a substance.

See below.: We have all grown accustomed to using it as it is. It works clinically and "better" is not always better. For example would an LD 20 or LD 90 be more useful? There is no incentive to change because it is good enough.