How long a high lasts depends entirely on what substance you’re talking about. A cannabis high from smoking typically lasts 1 to 2 hours, while an edible can keep you feeling effects for up to 12 hours. Stimulants, psychedelics, and even caffeine all follow their own timelines. Here’s a practical breakdown of what to expect from the most commonly used substances.
Cannabis: Smoking vs. Edibles
The method you use to consume cannabis makes a dramatic difference in how long the high lasts. When you smoke or vape, THC enters your bloodstream through your lungs and reaches your brain within seconds. The effects peak quickly and generally fade within 1 to 2 hours.
Edibles are a completely different experience. Because THC has to pass through your digestive system and liver before reaching your brain, the onset takes 30 to 90 minutes. Many people make the mistake of eating more during that waiting period, thinking the first dose didn’t work. The peak hits around 2 to 4 hours in, and the full experience can stretch up to 10 to 12 hours. THC-infused drinks and tinctures fall somewhere in between, with effects lasting roughly 4 to 6 hours.
Even after the high itself fades, impairment lingers. Colorado’s Department of Transportation recommends waiting at least 4 hours after smoking before driving, and at least 8 hours after eating an edible. Some high-potency products, particularly from unregulated sources, can cause intoxicating effects lasting longer than 12 hours. Combining cannabis with alcohol extends impairment further.
Alcohol
Alcohol doesn’t produce a “high” in the same way other substances do, but the buzzed or intoxicated feeling follows a predictable pattern tied to your blood alcohol concentration (BAC). Your liver clears alcohol at a fixed rate of about 0.015 BAC per hour, and nothing speeds that up: not coffee, not food, not a cold shower.
What surprises most people is how long impairment actually lasts after a night of heavy drinking. If you stop drinking at 2 a.m. with a BAC of 0.20 (which is about 10 standard drinks for an average person), you won’t be fully sober until around 4 p.m. the next day. At 8 a.m., you’d still be at a BAC of roughly 0.11, well above the legal driving limit. At 10 a.m., your judgment is still measurably impaired. The “good” feeling may have ended hours earlier, but the cognitive effects continue long after you stop feeling drunk.
Caffeine
Caffeine’s stimulating effects kick in about 15 to 45 minutes after you drink it, with most people feeling the peak around 30 to 60 minutes. The half-life of caffeine is 5 to 6 hours, meaning half the caffeine from your afternoon coffee is still active in your system at bedtime. The alertness and energy boost typically lasts 3 to 5 hours, but the residual stimulation can interfere with sleep for much longer, which is why a 3 p.m. coffee can still keep you up at midnight.
Stimulants
Cocaine produces an intense but short-lived high. When snorted, the euphoria lasts roughly 15 to 30 minutes, which is why people tend to use it repeatedly in a single session. Smoking crack cocaine produces an even shorter high of about 5 to 10 minutes.
Methamphetamine is on the opposite end of the spectrum. Its euphoric effects can last up to 24 hours, according to the National Drug Intelligence Center. This extended duration is part of what makes the crash afterward so severe, often involving extreme fatigue, depression, and intense cravings that can persist for days.
Psychedelics
LSD (acid) produces one of the longest highs of any recreational substance. A typical trip lasts 8 to 12 hours, with effects beginning 20 to 90 minutes after taking it. After the main trip ends, many people experience an “afterglow” period lasting another 6 hours or so, marked by lingering feelings of happiness, mild anxiety, or a sense of lightness. Between the trip itself and the comedown, it can take up to 24 hours for your body to return to its baseline state. Physical effects like elevated heart rate, nausea, and insomnia generally resolve within that same 24-hour window.
Psilocybin mushrooms produce a shorter experience, typically lasting 4 to 6 hours, with the peak occurring around 2 to 3 hours in.
Why the Same Substance Hits Differently Each Time
Several factors shift how long and how intensely you feel a high. Body weight, metabolism, hydration, whether you’ve eaten recently, and your overall health all play a role. But the single biggest variable for regular users is tolerance.
When you use a substance repeatedly, your body adapts in two ways. First, your liver gets more efficient at breaking it down, so the substance clears your system faster. Second, the receptors in your brain that the substance targets become less responsive, either decreasing in number or binding less strongly. The result is that the same dose produces weaker and often shorter effects over time. This is why a first-time cannabis user might feel high for 3 to 4 hours from smoking, while a daily user might feel effects for barely an hour from the same amount.
The reverse is also true. If you take a break and then return to a substance at your previous dose, the effects will be significantly stronger and longer-lasting than expected. This mismatch is a common cause of overdose, particularly with opioids and alcohol.
Quick Reference by Substance
- Cannabis (smoked/vaped): 1 to 2 hours, impairment up to 4 hours
- Cannabis (edibles): 4 to 12 hours, impairment up to 8+ hours
- Alcohol: BAC drops by 0.015 per hour; a heavy night can mean 14+ hours to full sobriety
- Caffeine: 3 to 5 hours of peak alertness, residual effects up to 10+ hours
- Cocaine (snorted): 15 to 30 minutes
- Methamphetamine: up to 24 hours
- LSD: 8 to 12 hours, plus a 6-hour afterglow
- Psilocybin mushrooms: 4 to 6 hours