Remember clonazepam is a long-acting benzo though, you'll feel the effects for a good hours. The half-life is much longer, but the actual effect is not nearly as long as the half-life. The half life is very long, but it depends on the dose and frequency. Usually it is said to be hours, but 1 mg will be. Learn about Klonopin (Clonazepam) may treat, uses, dosage, side effects, drug interactions, warnings, patient labeling, reviews, and related medications. Higher doses of 2, 3 and 4 mg/day in that study were less effective than the 1 mg/day dose and were associated with more adverse effects. Nevertheless, it is possible. Nov 5, - To determine how long it is likely to remain in your body following your final dose, it is necessary to consider the half-life of Klonopin's active Two people may take just a single 1 mg dose of Klonopin at the exact same time, yet the drug may stay in the system of one individual for significantly less time than.