Answer:
The best answer is: it depends on your tolerance. Have you ever taken Valium before? If so, how much?
Valium can not be injected from pill form so forget about that. You just have to take the pills orally. If you've got a tolerance, take whatever dose you're used to and increase it by 50%.
If you've got no tolerance, 10-20mg should work, depending on your bodyweight. If you're petite, obviously take less. If you're pretty big, you'll probably need to take towards the upper end of the range I gave.
Remember that Valium takes a while to kick in, so don't take too much or you'll fall asleep without enjoying it. Give it a good couple of hours to evaluate its effects before you take any more. It's nearly impossible to OD on Valium; it's a very safe substance, so your main concern is falling asleep and blowing the buzz and whatever money you spent to acquire it. Don't listen to the horror stories - all benzos are *extremely* safe, and if you look at any scientific literature, the doses required to overdose on diazepam (Valium is the name brand, diazepam is the generic chemical name) are insanely high.
I've been taking them for years for my back pain because it is a good strong muscle relaxer. Just take a couple if you've never taken them before. and you should get high.
Hope you have a good buzz. Best of luck to everyone.....
I'd like to add that this answer is not correct. It's very easy to die from benzos. It slows down your heart rate, so if you take too much. Your heat will just stop.
^No, this ISN'T correct. I know people who take up to 100mg-150mg of Valium and drink some wine with that dose too and he was FINE. I've watched them do so. I also had a close friend couple years ago try to kill himself with it and took almost 300mg and he just woke up the next morning on the floor with a very very bad hangover feeling. It depends on your tolerance like the OP said and also I personally wouldn't recommend drinking any alcohol with it. It's not a good idea at all. Just start out low the "peak" for it is between 30 mins. to 2 hours so keep that in mind. Just test the waters. No one can tell you what it should be for you personally. you kind of have to just experiment a little from what I've heard.