Ketamine has a very steep dose-response curve. It is a very different drug with very different effects at higher doses.
However, unlike other psychedelic drugs like LSD, Ketamine is a short trip, lasting no more than an hour and a half from start to finish. The duration is not affected by the dose. So if you're not enjoying yourself, it's all over pretty quickly.
common effects for snorted doses
low doses (10-75mg)
A small line of Ketamine, up to 50mg, will induce the mild, trippy euphoria that has led to its sale as an alternative to Ecstasy. Smells and tastes seem muted. Visual perception and sense of touch amplified.
medium doses (60-125mg)
everything is in slow motion, there's a buzzing or ringing in the ears, disconnection from your surroundings, loss of coordination and in less than ten minutes you'll yourself hardly able to move.
large doses (100-250 mg)
You're in the "K-Hole", where it is physically difficult to do anything other than lie in a near-comatose state and stare at the ceiling. In this state some users report life-altering insights about the meaning of life. Others are just scared.
mega doses (250 mg+)
Swallowing Ketamine results in slightly different effects. The drug goes straight to the liver when it is processed into norketamine. Norketamine has greater numbing, sedating and pain-killing effects and will make it more difficult to walk or move around. The psychedelic effects on the mind also come on slower and the whole experience can be much longer, lasting up to 4 hours. Snorted doses also trigger more 'out of body' effects than oral doses. (1
Unsurprisingly injected Ketamine is quicker acting and has significantly more powerful effects. Effects after an intravenous (iv) injection begin after 30 seconds and last around 10 minutes.
We strongly advise against intravenously injecting ketamine. You could pass out before finishing the injection.
Intramuscular injection (im) effects begin after 2-4 minutes and last up to an hour.
1. Ketamine: Dreams & Realities p.35