How long being high lasts depends almost entirely on what you took, how you took it, and how your body handles it. Smoking or vaping cannabis typically produces effects that peak within 10 to 30 minutes and fade over two to four hours. Edibles are a different story. Because they pass through the digestive system first, effects can take 30 minutes to two hours to appear and may last six to eight hours or longer. The drug itself matters just as much as the method. THC, the main psychoactive compound in cannabis, behaves very differently from alcohol, prescription sedatives, or stimulants.
How Long Does Being High Last?
For smoked cannabis, most people feel the main effects for two to four hours. Some residual fuzziness — slower thinking, dry mouth, altered sense of time — can linger a bit longer, especially with high doses or frequent use.
Edibles follow a slower curve. The liver converts THC into a more potent compound called 11-hydroxy-THC, which crosses into the brain more efficiently. That is one reason edible effects feel stronger and last longer than inhaled cannabis. A single edible dose can keep someone impaired for six to eight hours, and some people report effects lasting 12 hours or more after a large dose.
Other substances have their own timelines. Alcohol effects usually peak within 30 to 90 minutes and wear off in a few hours, depending on how much was consumed and how fast the body processes it. Benzodiazepines like diazepam can produce effects lasting many hours, and some metabolites stay active in the body much longer. Stimulants such as cocaine produce a short, intense high — often 15 to 30 minutes when smoked — followed by a crash.
No single number covers every substance or every person. Body weight, liver function, tolerance, and how often someone uses all shift the timeline.
Why Do Edibles Last Longer Than Smoking?
The route of absorption changes everything. When cannabis is smoked or vaped, THC moves from the lungs into the bloodstream within seconds and reaches the brain quickly. The liver is not the first stop, so the compound arrives largely unchanged.
When cannabis is eaten, it goes through the stomach and intestines, then into the liver before reaching general circulation. This is called first-pass metabolism. The liver converts a large share of the THC into 11-hydroxy-THC, a metabolite that is more potent and crosses the blood-brain barrier more readily than THC itself.
That conversion explains three things people notice with edibles:
- Delayed onset — it can take 30 minutes to two hours to feel anything
- Stronger peak effects — the metabolite is more psychoactive
- Longer duration — the body clears the metabolite more slowly than inhaled THC
This delay is why edible overdoses are common. Someone eats a dose, feels nothing after 45 minutes, eats more, and then both doses hit at once. Public health agencies in states where cannabis is legal consistently warn against redosing too soon.
Smoking and vaping also differ from each other. Vaping tends to produce effects similar to smoking, though the exact timing depends on the device and temperature. Neither route involves first-pass liver metabolism, so the high is shorter and more predictable than with edibles.
What Factors Affect How Long a High Lasts?
Several variables determine how long any psychoactive substance stays active. None of them work in isolation.
Dose. A larger dose almost always means longer effects. This is true for cannabis, alcohol, and sedatives alike. Doubling a dose does not simply double the duration, but it reliably extends it.
Tolerance. People who use a substance regularly often need more to feel the same effect, and their bodies may clear it faster. That said, tolerance does not make impairment safe or predictable.
Body composition and metabolism. THC is stored in fat tissue and released slowly over time. People with more body fat may clear it more slowly. Liver enzymes also vary between individuals, and some people metabolize drugs faster or slower based on genetics.
Method of use. Inhaled substances peak fast and fade fast. Ingested substances peak slowly and last longer. Injecting produces the fastest onset of all, with effects that can be intense but relatively short for some drugs.
Frequency of use. Chronic, heavy cannabis use can lead to a buildup of THC in fatty tissues. This does not mean someone stays high for days, but it can affect how quickly they return to a baseline state.
Other substances. Mixing drugs — including alcohol with cannabis or sedatives — can intensify effects and extend impairment. This combination is a well-documented risk factor for emergency room visits.
How Can You Tell If You Are Still Impaired?
Feeling “less high” is not the same as being unimpaired. Subtle effects on reaction time, coordination, and judgment can persist after the noticeable high has faded.
Signs that impairment may still be present include:
- Slowed reaction time or feeling mentally foggy
- Dry mouth, red eyes, or increased appetite
- Altered perception of time or distance
- Difficulty concentrating on a task
- Feeling unsteady or clumsy
For cannabis specifically, research on driving ability suggests that impairment can last several hours after smoking, and longer after edibles. Studies have found that THC can be detected in blood for hours to days after use, but detectable THC does not always mean active impairment. The relationship between blood THC levels and actual impairment is not straightforward, and there is no widely accepted legal or medical threshold that reliably predicts whether someone is too impaired to drive.
This is why public health guidance generally advises against driving for several hours after cannabis use, and longer after edibles. If you are unsure whether you are still impaired, the safest assumption is that you are.
How Long Does THC Stay in Your System?
How long a high lasts is not the same as how long a drug stays detectable in the body. These are two separate questions with very different answers.
THC and its metabolites can be detected in urine for days to weeks after use, depending on frequency and dose. In chronic heavy users, urine tests may remain positive for up to 30 days or more. Blood tests typically detect THC for a shorter window — usually hours to a few days. Hair tests can detect cannabis use for months.
Alcohol is different. It is cleared from the blood at a fairly consistent rate, and most standard tests can detect it for several hours to about a day after heavy drinking. Benzodiazepines vary widely — some are cleared quickly, while others remain detectable for days or weeks.
Being detectable is not the same as being high. A person can test positive for THC weeks after their last use and feel completely normal. This distinction matters for workplace testing, legal situations, and anyone trying to understand their own body.
When Should You Seek Medical Help?
Cannabis overdose is rarely life-threatening on its own, but it can be deeply uncomfortable and sometimes frightening. Symptoms of taking too much THC can include extreme anxiety, panic, rapid heart rate, nausea, vomiting, and a sense of losing control. These effects usually pass, but they can last several hours, especially with edibles.
Seek emergency help if someone experiences:
- Chest pain or a racing heartbeat that does not settle
- Difficulty breathing
- Severe confusion, hallucinations, or paranoia that does not improve
- Repeated vomiting or signs of dehydration
- Loss of consciousness
- Seizure activity
For alcohol, benzodiazepines, or opioids, the risks are more serious. Alcohol poisoning and opioid overdose can be fatal. Naloxone can reverse an opioid overdose and is available without a prescription in most US states. If you suspect an opioid overdose, call 911 immediately and give naloxone if available.
Mixing substances increases risk. Combining alcohol with benzodiazepines or opioids is a well-established cause of respiratory depression and death. No home remedy reverses that.
Does CBD Get You High?
CBD, or cannabidiol, does not produce the same psychoactive effect as THC. It does not bind to the same brain receptors that cause the classic high. Most CBD products sold in the US contain very little THC, though some may contain trace amounts.
That said, CBD can cause drowsiness, changes in appetite, and interactions with certain medications. It is not inert. And because CBD products are not tightly regulated in the US, the actual content can differ from what the label says. Some products marketed as CBD have been found to contain THC or other compounds not listed on the label.
If you take CBD and feel high, the product may contain more THC than expected. This is a quality control issue, not a normal effect of CBD itself.
Frequently Asked Questions
How long does a weed high last?
Smoked cannabis typically produces effects lasting two to four hours. Edible cannabis can last six to eight hours or longer because of how the liver processes THC.
Can you still be high the next day after an edible?
Yes, it is possible, especially after a large dose. Some people report lingering effects like fogginess or fatigue the next morning, though the intense high usually fades overnight.
How long does alcohol stay in your system?
Alcohol is usually detectable in the blood for several hours to about a day after drinking, depending on how much was consumed. Impairment can last longer than the detectable window.
Does drinking water or eating food make a high go away faster?
No. There is no evidence that water, food, coffee, or cold showers speed up the clearance of THC or most other drugs from the body. Time is the main factor.
