How long a high lasts depends almost entirely on what substance is involved and how it enters your body. A hit of smoked cocaine fades in 5 to 10 minutes, while a cannabis edible can keep you elevated for up to 12 hours. Below is a practical breakdown of the most commonly searched substances, covering onset, peak, total duration, and what the comedown feels like.
Cannabis: Smoked vs. Edibles
Smoking or vaping cannabis produces effects within seconds to a few minutes. The high peaks around 30 minutes in and can last up to 6 hours total, though most people feel functionally normal well before that. Residual effects like mild grogginess or slowed reaction time can linger up to 24 hours.
Edibles are a different experience entirely. Because THC has to pass through your digestive system first, effects don’t kick in for 30 minutes to 2 hours. This delay is the main reason people accidentally take too much: they eat more thinking the first dose “didn’t work.” The high peaks around 4 hours after eating and can last up to 12 hours, with residual effects stretching to 24 hours. If you’ve eaten a strong edible and feel overwhelmed, the most honest advice is that you’ll need to wait it out.
THC is fat-soluble, meaning your body stores it in fatty tissue and releases it slowly. You can feel completely sober but still have detectable THC in your system days or even weeks later, especially with regular use. Blood concentrations drop quickly within 3 to 4 hours after smoking, but occasional users can test positive in blood for up to 12 hours, and regular users for 24 to 48 hours.
Cocaine: Intense but Short
Cocaine produces one of the shortest highs of any recreational drug. Snorting it delivers a high lasting 15 to 30 minutes. Smoking it (as crack) is even shorter: 5 to 10 minutes. Injection and smoking produce a faster, more intense rush than snorting, but the tradeoff is that the effects burn out quicker. This short duration is a big part of why cocaine carries such a high risk for compulsive redosing.
LSD: The Long Haul
LSD has one of the longest durations of any psychoactive substance. Effects begin 20 to 90 minutes after taking a tab and typically last 6 to 12 hours, though some trips stretch to 15 hours. There’s no reliable way to cut the experience short once it starts.
LSD also produces measurable “afterglow” effects the next day. A controlled study of healthy volunteers found that 24 hours after a dose, participants showed improved visual memory and verbal fluency but reduced cognitive flexibility compared to placebo. In practical terms, you may feel mentally loose and creative the day after, but also a bit rigid in your thinking or easily stuck on tasks that require switching between different rules.
MDMA (Ecstasy): A Predictable Arc
MDMA effects come on within 20 to 60 minutes of swallowing a pill or capsule. The high peaks around 2 hours in, often with waves of physical warmth and energy. Less intense effects persist for 4 to 6 hours total, with some residual feelings lasting beyond that.
The comedown is the defining feature of MDMA for many people. In the hours and days after, you can expect low mood, anxiety, irritability, difficulty sleeping and concentrating, and an upset stomach. These effects happen because MDMA temporarily depletes your brain’s supply of mood-regulating chemicals. Research has found that encoding of emotional memories can still be impaired 48 hours after a dose.
Heroin and Opioids
Injecting heroin into a vein produces a rush within 7 to 8 seconds that lasts from 45 seconds to a few minutes. After the rush fades, a warm, drowsy state called “the nod” sets in and can last up to an hour. The overall effects of heroin generally last 3 to 5 hours depending on dose. Injecting under the skin or into muscle delays onset to about 5 to 8 minutes but produces a similar total duration.
Fentanyl, being far more potent by weight, can produce effects at much smaller doses, but the general timeline is comparable. The critical danger with opioids is that respiratory depression (slowed breathing) persists through the entire duration, not just during the pleasurable phase.
Alcohol: Slower Than You Think
Your body processes alcohol at a fixed rate of about one standard drink per hour, regardless of how much you consume. That means four drinks in an hour will take roughly four hours to fully metabolize. The “high” or buzz from alcohol depends on how fast you drink relative to that clearance rate. Drinking faster than one per hour means your blood alcohol climbs; drinking slower means it stays low or falls.
Legal impairment (a blood alcohol level of 0.08 to 0.10) can be reached with just a few drinks depending on body weight, and the effects last until your liver catches up. Residual impairment, including slower reflexes and impaired judgment, can persist even as you start to feel sober.
Why Duration Varies Between People
Two people taking the same substance at the same dose can have meaningfully different experiences. Body composition is the biggest factor. People with more body fat will retain fat-soluble substances like THC for longer. People with less total body water, which includes most older adults (who lose 10 to 15% of their body water with age), will feel stronger effects from water-soluble substances like alcohol because the drug is concentrated in a smaller volume of fluid.
Tolerance matters too. Regular use of nearly any substance trains your body to metabolize it faster and your brain to respond less intensely, shortening and blunting the perceived high. Conversely, someone with no tolerance will feel stronger effects for longer at the same dose. Food in your stomach, hydration, sleep, and liver health all play secondary roles. The method of consumption is often more important than any of these individual factors: smoking and injecting deliver substances to the brain in seconds, while oral routes can delay onset by hours.