Methamphetamine is a very potent stimulant drug, people who are addicted and using everyday take insanely excessive amounts. Let's say you have a gram of Methamphetamine, and let's say it's 90% purity which is actually considerably low. That's 900 milligrams of Methamphetamine. No matter how you take it, that's a lot of drugs for the average person. Meth is very effective even orally, and very long lasting this way.
Some people are using this much daily. To put this into perspective, a 30 count Adderall prescription has anywhere from 300 (10s), 600 (20s) to 900 (30s) milligrams of Amphetamine, a considerably less potent closely related compound. Some folks are using more than a gram a day, and grams of meth here in the United States go scary cheap. It's the 2nd most common "street drug" in the country, next to Marijuana.
I know all of this is not related to the question, but hopefully it will give you insight on the insanity at hand here. And please... DONT shoot this shit up man! You can take it literally any other way, honestly your probably best of snorting it and avoid other ROAs. Oral is very, very long lasting do not undermine it. Please take my advice friend! It's in your best interest.
Much love

~ RoBoInSlowMo