Ketamine abuse can harm numerous main organs, including the digestive tract, urinary tract, and brain. Drug addiction also puts pressure on the liver and kidneys, causing lasting damage to these organs. Two of the most serious physical side effects of ketamine include ulcerative cystitis and memory loss.

Impaired memory, mood fluctuations, respiratory distress, bladder and urine difficulties, high heart rate, seizures, overdose, and other long-term side effects are possible.

Physical tolerance to, and dependence on, ketamine is the most dangerous long-term outcome of recurrent, high-dose ketamine misuse. Memory deficits, bladder, and renal problems, and depression are all long-term complications of ketamine use.

 The duration of ketamine effects is regulated by how the medicine is administered. Ketamine has instant effects when smoked. Snorting it (as in recreational misuse) generates effects in as short as five minutes, whereas those who take ketamine orally may expect numbness to begin around 15 minutes after intake. The delivery route is the main factor that influences the period of effects. The ketamine will be broken down in around 45 minutes if you take it by injection. The snorting influence of the medication can work up to an hour, and oral intake effects up to two hours. The effects of the medication can last up to an hour if snorted, and up to two hours if taken orally.

Ketamine is a relatively fast-acting drug, which encourages some users to binge on it, getting very high and then taking more ketamine during the unpleasant comedown. There is a risk of developing a psychological dependence on ketamine, but cases of ketamine withdrawal (the body's inability to function without the drug) are uncommon. Instead, users will experience intense cravings for more ketamine as well as disorienting flashbacks to the psychological effects of the drug.