500mcg is equipotent to .5mg. There are 1,000mcg in one Milligram (Mg)
The Benzodiazepines are not typically, initially labelled as overtly euphoric substances for the majority of people. They are excellent at their intended purpose. Anxiolysis, sedation and stuff like that are typical effects. There's a paradox in that it is very common for users to not understand or properly perceive how intoxicated they are. They have a numbing effect in which they blunt emotion, your senses and everything.
For some people, this is a very euphoric experience indeed. Some people struggle with crippling anxiety that when it's taken out of the picture for a moment, they feel "normal". Otherwise, they are not drugs that are typically used for anything other than sedating yourself after using other drugs (stimulants), for hypnosis, sedation/anxiolysis or, if you're outside, for upping your overall likelihood of police encounter.
I don't usually like a lot of threads dedicated to getting or staying high, but I always try to leave threads open in which new users of Benzodiazepines have questions. I feel that they can be quite dangerous and advice is required to not do stupid shit.