Categories
BLOG

half track of weed

How Long Does Marijuana Stay in Your System?

Marijuana in Your Blood, Urine, Hair, & Saliva

  • facebook
  • twitter

Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.

The effects of marijuana fade quickly, but the drug can be detected in the body for weeks and sometimes longer. The amount of time the active ingredients and breakdown products of weed remain in the system can range from a few hours to 90 days, depending on how often or how much marijuana the person has been using.

Although a number of states in the U.S. have active medical marijuana laws and recreational use of marijuana for adults over the age of 21 is legal in 11 states, Washington, DC, the Northern Mariana Islands, and Guam, the federal government continues to classify marijuana as a Schedule I controlled substance.

According to the Substance Abuse and Mental Health Services Administration (SAMHSA), roughly 1 in 10 people who use marijuana will become addicted—and these rates rise to 1 in 6 if they start using the drug prior to age 18.

The FDA has not yet approved medical marijuana for any medical indication, but it is often prescribed for chronic pain, nausea, HIV, multiple sclerosis, glaucoma, and irritable bowel syndrome (IBS).

How Long Does It Take to Feel the Effects?

The effects of marijuana can vary from person to person. Some people may feel euphoric and relaxed while others feel anxious and paranoid. In other cases, people report feeling “dopey” and experience a loss of interest in activities or an inability to grasp concepts.

The chemical in marijuana that makes you feel “high” is tetrahydrocannabinol, also called delta-9-THC or simply THC. It enters the body’s bloodstream rapidly after smoking marijuana.

If marijuana is ingested orally rather than smoked, it takes longer to be absorbed into the blood, usually from 20 minutes to an hour and a half, but this can vary based on the amount taken as well as physiological factors such as absorption and rates of metabolism and excretion can influence drug concentrations in circulation.  

Effects can be far-ranging depending on the strain, method of consumption, and amount and can include the following:

  • Dry mouth
  • Swollen eyelids
  • Bloodshot eyes
  • Pleasurable body sensations
  • Increased appetite (“the munchies”)
  • Relaxation
  • Stimulation
  • Distorted perception (sights, sounds, time, touch)
  • Loss of coordination
  • Trouble with thinking, memory, and problem-solving
  • Increased heart rate

The short-term effects of marijuana on memory, learning, problem-solving, and coordination last for one to two hours, with some lingering effects for up to 24 hours.   It’s been shown to impair your driving performance for up to three hours, according to the National Highway Safety Administration.

The effects of marijuana are also influenced by the terpene profiles of a given strain. For instance, citrus terpene profiles tend to be more stimulating, which may be the desired effect, or may contribute to someone feeling anxious.

It is important to know that not all marijuana is created equal. Unlike other prescription drugs, marijuana products aren’t standardized and can vary considerably in quality, makeup, and dosage.

This variance may contribute to how quickly you feel the effects and what those effects are. THC can interact with alcohol, blood thinners, and anti-anxiety medications, so it’s important to discuss your marijuana use with your doctor.

How Long Does Marijuana Last?

The half-life of marijuana is how long it takes for half of the drug to be metabolized and eliminated from the bloodstream. While there are many different cannabinoids, THC is the one most drug tests are looking for.

THC is rapidly broken down and modified into molecules known as metabolites. At least 80 different metabolites are formed from THC and may have their own effects on the body’s endocannabinoid system. These metabolites are stored in body fat and are gradually eliminated from the body through feces and urine.

Some THC metabolites have an elimination half-life of 20 hours whereas others are stored in body fat and have an elimination half-life of 10 to 13 days.  

It takes five to six half-lives for a substance to be almost entirely eliminated. This is why you see advice that one-time use is probably not detectable after five to eight days.

Blood and Saliva

Because marijuana stays in the bloodstream for only a short time, blood tests for marijuana are usually not used. The exceptions are in the case of automobile accidents and some roadside sobriety checkpoints.

Blood or saliva tests can show current intoxication. However, unlike blood alcohol concentration tests, they do not indicate a level of intoxication or impairment.

Daily or near-daily cannabis consumption is likely, but not always, detectable by a hair test up to three months later. But, the hair test is not reliably able to detect infrequent cannabis use or determine the amount of cannabis used.  

Urine

Urine tests for marijuana metabolites also only show recent marijuana use, not current intoxication or impairment. This is because of the time required between use and your body breaking down THC to the metabolites that are eliminated in the urine. Because many employers have a zero-tolerance for drug use, most workplaces use urine tests to detect recent use of drugs.

False Positive Testing

Workplace testing for marijuana might entail first screening the sample with an immunoassay test, known as the EMIT or RIA. If positive results are returned, the sample is again screened with a gas chromatograph-mass spectrometer (GCMS), which is much more accurate and so false positives are rare.  

No known substances would cause a marijuana urine test to return a false positive.

At one time, ibuprofen (sold over-the-counter as Advil, Motrin, and Nuprin) would cause false marijuana positives. But today’s tests have been adjusted to eliminate that problem.

In places where marijuana is legal, roadside blood tests have been known to show some false positives in people who had been legally consuming cannabis but were not actively intoxicated at the time of the test. A 2016 report detailed a Belgian policy of testing oral fluid at the roadside that found it decreased these types of false positives.  

Factors That Affect Detection Time

The length of time marijuana remains in your body depends on many different factors, including frequency of use, body mass, metabolism, sex, and hydration levels.

Frequency of Use

There is some evidence that the length of time that marijuana remains in the body is affected by how often the person uses marijuana, how much they use, and how long they have been using.

People who use marijuana regularly have reported positive drug test results after 45 days since last use, and people who use more heavily have reported positive tests up to 90 days after quitting.

In a 2017 study of 136 people who use cannabis subjected to hair tests, the presence of five cannabinoids, THC, THC-OH, THC-COOH, cannabinol, and cannabidiol, were present in 77% of the heavy users and 39% of the light users.  

Women often metabolize THC at a slightly slower rate since they tend to have higher levels of body fat than male counterparts.

Metabolism

The faster your metabolism, which can be impacted by age, physical activity, and certain health conditions, the faster marijuana will exit your body.

Body Mass Index (BMI)

THC metabolites are often stored in the fat cells in your body, so the higher your body fat (or BMI), the slower you’ll likely be able to metabolize and excrete marijuana.

Hydration

When you’re dehydrated, you’ll have more concentrations of THC in the body. Flooding yourself with water won’t make you pass a drug test, however. Instead, it will dilute it and you’ll likely need to retake the test.

Smoking vs. Vaping vs. Edibles

The method of use also impacts the detection time. If marijuana is smoked or vaped, the THC levels in the body will drop faster than if you ingest it. Edibles take longer to break down in the body and leave your system.

How to Get Marijuana Out of Your System

Many employers have a workplace drug policy that includes random drug testing for current employees and routine testing for all new job applicants.

If you are required to take a urine test on short notice for employment or other purposes and you have recently smoked marijuana, you are probably going to fail the test. This is particularly true if your use is regular or heavy.

You can be fired for failing a drug test even in states where the recreational use of marijuana has been legalized.

The only completely reliable way of passing the test is to stop smoking or ingesting marijuana or cannabis products.

Although you will see many tips on how to beat a marijuana drug test, most have proven to be urban legends. Some of these questionable techniques include the following.

Washing Your System Out

This method entails drinking a lot of water or liquids and urinating several times before the test, then taking vitamin B-12 to add color back to the urine. Although this may lower the percentage of THC found in the urine by diluting it, it will not totally eliminate THC metabolites.

Some people will also try to exercise before the test, but that can actually backfire, depending on the test, as it can release stored THC from fat into the blood, according to one study in the journal Drug and Alcohol Dependence.  

Using Drug Screening Agents

Some companies sell various substances and herbal teas that are allegedly capable of “cleaning” the body’s system of traces of marijuana. There is little evidence that any of them actually work. The catch is that most of them have to be used over an extended period of time, during which the body will naturally eliminate THC anyway.

Tampering With the Test

This involves adding something to the urine to contaminate the sample. There are tales of using Visine, bleach, salt, or detergent to the urine sample, but these items are easily detected by the lab.

Several commercial products are sold as urine test adulterants, but none are 100% foolproof. All of them can be detected by the laboratory if a separate test is run for them.

Symptoms of Overdose

It is very difficult to physically overdose on marijuana because the lethal dose is so much higher than the effective dose. Very few marijuana overdoses have ever been reported. If someone you know has taken too much marijuana, and that is the only thing they have taken, an overdose is highly unlikely, but that doesn’t mean that marijuana is not harmful.  

Psychological distress is possible as is impairment of judgment, both of which can lead to hazardous behaviors that can harm yourself and someone else. Although rare, people can experience THC toxicity when using marijuana in high doses, especially in the form of edibles. Symptoms can include:

  • Heart arrhythmias
  • Psychosis or paranoia (or exacerbation of pre-existing mental health conditions)
  • Seizures
  • Uncontrollable vomiting

If you or someone you love has a family history of mental illness, it is beneficial for you to consult your doctor before using marijuana.

The concept of “set and setting” is also important. Since people who have taken too much marijuana can experience sensory overload, minimizing overstimulating inputs in the environment can help them to relax. Some people are also more affected by marijuana than others.

Getting Help

You may have a prescription for medical marijuana, or you may want to partake of weed or marijuana edibles in states where it is now legal for recreational use at the state level. There is a common perception that you cannot develop a physical dependence on marijuana, but this is not the case. Psychological dependence is also a consideration.

If you discontinue marijuana after regular or heavy use, you may experience symptoms of withdrawal. Signs of marijuana withdrawal include:

  • Appetite change
  • Cramps or nausea after eating
  • Cravings
  • Digestion problems
  • Headaches
  • Mood swings
  • Sleep disruption
  • Weight gain
  • Weight loss

If you find that you can’t handle symptoms of withdrawal without relapsing, you may be at risk for a substance use disorder. Do not be afraid to seek out professional support from a mental health professional.

There are therapists who can help you understand your reasons for using. They also can help you determine how cannabis use is impacting your life, and how to develop a plan to stop using if that ends up being the best choice for you.

If you or a loved one are struggling with substance use or addiction, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

For more mental health resources, see our National Helpline Database.

Marijuana, known as weed or pot, can last anywhere from a few hours to 90 days, depending on several factors including the type of drug test used.

Here’s what marijuana actually does to your body and brain

Marijuana’s official designation in the US as a Schedule 1 drug — something with “no currently accepted medical use” — means it has been pretty tough to study.

That remains the case, despite the fact that, at a state level, the drug is increasingly accessible for the general public. As of Election Day 2020, when Arizona, Montana, New Jersey, and South Dakota gave the green light to marijuana use for adults, 1 in 3 Americans live in a state where they can legally buy cannabis.

Despite the limitations to scientists studying the drug, a growing body of research and numerous anecdotal reports have found links between cannabis and several health benefits, including pain relief and the potential to help with certain forms of epilepsy.

In addition, researchers say there are many other ways marijuana might affect health that they want to better understand — including a mysterious syndrome that appears to make marijuana users violently ill.

Along with several other recent studies, a massive report released by the National Academies of Sciences, Engineering, and Medicine in 2017 helps sum up exactly what we know — and what we don’t — about the science of weed. Here’s what you should know about how marijuana affects the brain and body.

Marijuana use is linked to a rare syndrome that causes nausea and vomiting.

Most recently, a March 2019 study looked at over 2,500 cannabis-related ER visits in Colorado. They found that stomach issues like nausea and vomiting were the main driver of the trips, even before psychiatric problems like intoxication and paranoia.

In 2004, Australian doctors began looking into these stomach symptoms based on the experiences of a local woman who used to be able to smoke marijuana with no issue, and then seemingly out of nowhere began having adverse reactions that paralleled those in the 2019 study.

They gave her condition a name: cannabinoid hyperemesis syndrome, or CHS. The rare illness is still fairly new and understudied, but researchers believe it might affect a large population.

“CHS is certainly not very rare,” Andrew Monte, an associate professor of emergency medicine at UCHealth University of Colorado Hospital who led the March study, previously told Business Insider. “We see it absolutely every week in our ER.”

Marijuana can make you feel good.

One of weed’s active ingredients, tetrahydrocannabinol (THC) interacts with the brain’s reward system, the part that has been primed to respond to things that make us feel good, like eating and sex.

When overexcited by drugs, the reward system creates feelings of euphoria. This is also why some studies have suggested that excessive marijuana use can be a problem for some people — the more often you trigger that euphoria, the less you may feel during other rewarding experiences.

In the short term, it can also make your heart race.

Within a few minutes of inhaling marijuana, your heart rate can increase by between 20 and 50 beats a minute. This can last anywhere from 20 minutes to three hours, according to the National Institute on Drug Abuse.

The NASEM report found insufficient evidence to support or refute the idea that cannabis might increase the overall risk of a heart attack. The same report, however, also found some limited evidence that smoking could be a trigger for a heart attack.

Marijuana’s effects on the heart could be tied to effects on blood pressure, but the link needs more research.

In August, a study published in the European Journal of Preventive Cardiology appeared to suggest that marijuana smokers face a threefold higher risk of dying from high blood pressure than people who have never smoked — but the study came with an important caveat: it defined a “marijuana user” as anyone who’d ever tried the drug.

Research suggests this is a poor assumption — and one that could have interfered with the study’s results. According to a recent survey, about 52% of Americans have tried cannabis at some point, yet only 14% used the drug at least once a month.

Other studies have also come to the opposite conclusion of the present study. According to the Mayo Clinic, using cannabis could result in decreased — not increased — blood pressure.

So while there’s probably a link between smoking marijuana and high blood pressure, there’s not enough research yet to say that one leads to the other.

Weed may also help relieve some types of pain.

Pot contains cannabidiol, or CBD, a chemical that is not responsible for getting you high but is thought to be responsible for many of marijuana’s therapeutic effects. Those benefits can include pain relief or potential treatment for certain kinds of childhood epilepsy.

The new report also found conclusive or substantial evidence — the most definitive levels — that cannabis can be an effective treatment for chronic pain, which could have to do with both CBD and THC. Pain is also “by far the most common” reason people request medical marijuana, according to the report.

Pain relief could include the discomfort of arthritis.

One of the ways scientists think marijuana may help with pain is by reducing inflammation, a component of illnesses like rheumatoid arthritis.

A preliminary 2005 study of 58 patients with RA, roughly half of whom were given a placebo and roughly half of whom were given a cannabis-based medicine called Sativex, found “statistically significant improvements in pain on movement, pain at rest, quality of sleep” for patients on Sativex.

Other studies testing other cannabinoid products and inhaled marijuana have shown similar pain-relieving effects, according to the report.

Individuals with inflammatory bowel disease may also find some relief.

Some people with inflammatory bowel diseases like Crohn’s and ulcerative colitis could also benefit from marijuana use, studies suggest.

A 2014 paper, for example, describes two studies of people with chronic Crohn’s. Half were given the drug and half got a placebo. That study showed a decrease in symptoms in 10 of 11 subjects using cannabis, compared with just four of 10 on the placebo. But when the researchers did a follow-up study using low-dose CBD, they saw no effect in the patients.

Researchers say that, for now, we need more research before we’ll know whether cannabis can help with these diseases.

Marijuana may also be helpful in controlling epileptic seizures.

The drug can be prescribed to people with Lennox-Gastaut syndrome and Dravet syndrome, two rare forms of epilepsy. In fact, it is the first FDA-approved treatment option for Dravet syndrome.

In the clinical trial for the drug, common side effects included sleepiness, fatigue, decreased appetite, diarrhea, and insomnia.

But it can also mess with your sense of balance.

Marijuana may throw off your balance, as it influences activity in the cerebellum and basal ganglia, two brain areas that help regulate balance, coordination, reaction time, and posture.

And it can distort your sense of time.

Feeling as if time is sped up or slowed down is one of the most commonly reported effects of using marijuana. A 2012 paper sought to draw some solid conclusions from studies on those anecdotal reports, but it was unable to do so.

“Even though 70% of time estimation studies report overestimation, the findings of time production and time reproduction studies remain inconclusive,” the paper said.

In a 1998 study that used magnetic resonance imaging (MRI) to focus on the brains of volunteers on THC, the authors noted that many had altered blood flow to the cerebellum, which most likely plays a role in our sense of time.

Limitations on what sort of marijuana research is allowed make it particularly difficult to study this sort of effect.

Weed can also turn your eyes red.

Since weed makes blood vessels expand, it can give you red eyes.

And you’ll probably get the munchies.

A case of the munchies is no figment of the imagination — both casual and heavy marijuana users tend to overeat when they smoke.

A recent study in mice suggested the possibility that marijuana may effectively flip a circuit in the brain that is normally responsible for quelling the appetite, triggering us to eat instead.

It all comes down to a special group of cells in the brain that are normally activated after we have eaten a big meal to tell us we’ve had enough. The psychoactive ingredient in weed appears to activate just one component of those appetite-suppressing cells, making us feel hungry rather than satisfied.

A 2014 study found that marijuana use had no effect on body weight, despite the munchies phenomenon commonly associated with use.

Some women have reported having more satisfying sex when using marijuana.

A small study of 373 women from of varying races, sexual orientations, and marital statuses found that people who said they used marijuana before sex tended to have a more pleasurable experience than those who did not use the substance.

Specifically, some women reported having more satisfying orgasms and an increase in their sex drive.

Researchers weren’t able to pinpoint why marijuana had this effect, but suggested it could be due to the substance’s ability to reduce stress and anxiety.

Marijuana may also interfere with how you form memories.

Marijuana can mess with your memory by changing the way your brain processes information, but scientists still aren’t sure exactly how this happens. Still, several studies suggest that weed interferes with short-term memory, and researchers tend to see more of these effects in inexperienced or infrequent users than in heavy, frequent users.

Unsurprisingly, these effects are most evident in the acute sense — immediately after use, when people are high.

According to the new NASEM report, there was limited evidence showing a connection between cannabis use and impaired academic achievement, something that has been shown to be especially true for people who begin smoking regularly during adolescence. (That has also been shown to increase the risk for problematic use.)

Importantly, in most cases, saying cannabis is connected to an increased risk doesn’t mean marijuana use caused that risk.

In some people, weed could increase the risk of depression.

Scientists can’t say for sure whether marijuana causes depression or depressed people are simply more likely to smoke. But one study from the Netherlands suggests that smoking weed could raise the risk of depression for young people who already have a special serotonin gene that could make them more vulnerable to depression.

Those findings are bolstered by the NASEM report, which found moderate evidence that cannabis use was linked to a small increased risk of depression.

And it may also increase the risk of developing schizophrenia.

The NASEM report also found substantial evidence of an increased risk among frequent marijuana users of developing schizophrenia — something that studies have shown is a particular concern for people at risk for schizophrenia in the first place.

Regular marijuana use may also be connected to an increased risk of social anxiety.

Researchers think it’s possible that CBD might be a useful treatment for anxiety disorders, and that’s something that several institutions are currently trying to study.

The recent report suggested that evidence of a link between marijuana and an increased risk of most anxiety disorders was limited.

However, the authors wrote that there is moderate evidence that regular marijuana use is connected to an increased risk of social anxiety. As in other cases, it’s hard to know whether marijuana use causes that increase or people use marijuana because of an increased risk of social anxiety.

Marijuana use could also affect sperm count.

A small study of 37 men found that those who used marijuana had decreased sperm counts than those who never used marijuana. The study did not specify the methods of marijuana consumption used.

Another study, however, found that marijuana increased sperm count in men. This study was larger and looked at 1,215 healthy young men. They found that men who currently or previously used marijuana had both higher sperm counts and higher sperm concentrations than men who never used the substance.

A person could need more sedation medication for surgery if they have a regular marijuana habit.

A small study in the May 2019 issue of The Journal of the American Osteopathic Association found that people who reported smoking marijuana or eating edibles on a daily or weekly basis needed higher doses of medication for sedation.

The researchers found that people who used marijuana daily or weekly needed 14% more fentanyl, 19.6% more midazolam, and 220.5% more propofol (all medications that are used for sedation) for the full length of their procedures than their counterparts who didn’t use as much marijuana.

Researchers haven’t determined why this was the case, but they believe marijuana could potentially desensitize the body’s receptors that process sedatives.

It’s worth noting that marijuana has likely gotten stronger since the 1980s, and that its ratio of THC to CBD has changed as well.

The THC content of marijuana across the US has tripled since 1995, according to a large recent study in which researchers reviewed close to 39,000 samples of cannabis. While THC levels hovered around 4%, on average, in 1995, they skyrocketed to roughly 12% in 2014.

Meanwhile, the CBD content in marijuana — the part that’s responsible for many of the drug’s therapeutic effects — has dropped, the researchers found, shifting the ratio of THC to CBD from 14:1 in 1995 to about 80:1 in 2014.

Still, tracking THC potency over time can be tricky. The older a weed sample gets, the more its THC appears to degrade. How it is stored matters too. These two barriers could be interfering somewhat with the metrics on pot’s potency.

Most importantly, regular weed use is linked with some specific brain changes — but scientists can’t say for sure whether one causes the other.

In a recent study, scientists used MRI brain scans to get a better picture of the brains of adults who have smoked weed at least four times a week for years.

Compared to people who rarely or never used the drug, the long-term users tended to have a smaller orbitofrontal cortex, a brain region critical for processing emotions and making decisions. But they also had stronger cross-brain connections, which scientists think smokers may develop to compensate.

Still, the study doesn’t show that smoking pot caused certain regions of the brain to shrink; other studies suggest that having a smaller orbitofrontal cortex in the first place could make someone more likely to start smoking.

Most researchers agree that the people most susceptible to brain changes are those who begin using marijuana regularly during adolescence.

A small study of teenagers in Europe found that people who used marijuana had more gray matter in their brains, which can affect how humans mature over time.

The researchers noticed these brain-level changes in teens who had just one or two joints in their lifetimes.

Although researchers are unsure whether higher brain volume is bad for health, they do know brain volume naturally decreases during the aging process, according to the National Institutes of Health (NIH).

An international meta-analysis of 23,317 young adults also found that marijuana use could increase risk for depression, anxiety, and suicidal thoughts.

“Although the causes of major depressive disorder are multifactorial and complex, this meta-analysis suggests that the cannabis exposure could be 1 factor contributing to depression in young adulthood,” the researchers wrote.

Marijuana use affects the lungs but doesn’t seem to increase the risk of lung cancer.

People who smoke marijuana regularly are more likely to experience chronic bronchitis, according to the report. There’s also evidence that stopping smoking relieves these symptoms.

Yet perhaps surprisingly, the report’s authors found moderate evidence that cannabis was not connected to any increased risk of the lung cancers or head and neck cancers associated with smoking cigarettes.

Other forms of marijuana consumption, like vaping or eating edibles, have not been linked to increased cancer risk like smoking has been linked.

“When you combust any plant, you’re creating significantly more carcinogens,” Dr. Jeffrey Chen, the director of the UCLA Cannabis Research Initiative, previously told INSIDER.

Some athletes think marijuana could be used in ways that might improve certain types of physical performance.

Some athletes, especially in certain endurance and adventure sports, say marijuana use can boost their athletic performance. This may be because of anti-inflammatory or pain-relieving effects that make it easier to push through a long workout or recover from one.

At the same time, there are ways that marijuana could impair athletic performance, since it affects coordination and motivation, and dulls the body’s natural recovery process.

Without more research, it’s hard to know how marijuana affects athletic performance.

There’s evidence that marijuana use during pregnancy could have negative effects.

According to the new NASEM report, there’s substantial evidence showing a link between prenatal cannabis exposure — when a pregnant woman uses marijuana — and lower birth weight. There was limited evidence suggesting that using marijuana during pregnancy could cause complications and increase the risk that a baby would have to spend time in a neonatal intensive care unit.

A study published in JAMA Psychiatry in September 2020 found that pregnant women who used marijuana had a higher risk of their children having ADHD and/or psychotic behaviors that have been linked to schizophrenia.

And an analysis, published in Nature Medicine in August 2020, linked cannabis use among pregnant women to autism in their children. The study, conducted in Ontario, Canada, involved data from 3,000 women who used cannabis during pregnancy.

Still, pregnant and breastfeeding women have reported using the drug to relieve nausea, pain, and depression symptoms since traditional NSAID painkillers are not allowed during pregnancy.

Experts say they have little information about the potential health risks associated with this practice, so they urge mothers to abstain from marijuana consumption.

CBD pills could help people cut down on marijuana use or quit.

Cannabis use disorder is a diagnosis that describes dependence on cannabis, making it hard to consume less of, or none of, the drug.

But in a study published in July 2o2o, UK researchers found that using CBD pills could wean people off cannabis if they have been diagnosed with cannabis use disorder.

“Unlike THC, CBD does not produce intoxicating or rewarding effects and it shows potential for a treating several other medical disorders,” lead author Dr. Tom Freeman said.

There are still so many questions about how marijuana affects the body and brain that scientists say far more research is needed.

Based on the available evidence and conversations with researchers, there are good reasons to think marijuana has potentially valuable medical uses. At the same time, we know that, as with any substance, not all use is risk-free.

More research is needed to figure out how to best treat the conditions that cannabis can help and how to minimize any risks associated with medical or recreational use.

Staci Gruber, an associate professor of psychiatry at Harvard Medical School and the director of the Marijuana Investigations for Neuroscientific Discovery program at McLean Hospital, told Business Insider that marijuana research is essential in determining “how best we can use it, what are the safest ways, and what are the real risks.”

Kevin Loria contributed to a previous version of this story.

Healthcare Explained:

SEE ALSO: Silicon Valley’s LSD habit is exploding, and now a 27-year old is offering how-to tutorials over Skype

DON’T MISS: A scientist leading the largest marijuana study in history says it’s ‘5x stronger’ than in 1980 — but there’s a catch

  • cannabinoids
  • CBD
  • THC
  • 420 day
  • 4/20
    * Copyright © 2020 Insider Inc. All rights reserved. Registration on or use of this site constitutes acceptance of our
  • Terms of Service , Privacy Policy and Cookies Policy .
  • Sitemap
  • Disclaimer
  • Commerce Policy
  • CA Privacy Rights
  • Coupons
  • Made in NYC
  • Jobs
  • Stock quotes by finanzen.net
  • Reprints & Permissions
    International Editions:
  • United States US
  • International INTL
  • Australia AUS
  • Deutschland DE
  • España ES
  • France FR
  • India IN
  • Italy IT
  • Japan JP
  • México MX
  • Netherlands NL
  • Nordic SE
  • Polska PL
  • South Africa ZA

She’s broken news on a variety of life science and health-tech stories, including:

Before joining BI, Erin worked as a freelance health and science reporter for outlets including Newsweek, Popular Science, and Scientific American.

Erin graduated summa cum laude from the University of California, San Diego and received her master’s from the Newmark Graduate School of Journalism in New York, where she spent an extra semester completing her degree after breaking both wrists in a snowboarding accident.

Julia Naftulin is a health reporter at Insider covering sex, relationships, dating, and recreational drugs including cannabis and psychedelics. She also writes Insider’s relationship advice column Doing It Right.

Julia is here to answer all of your questions about dating, love, and doing it — no question is too weird or taboo. Julia regularly consults a panel of health experts including relationship therapists, gynecologists, and urologists to get science-backed answers to your burning questions, with a personal twist.

Have a question? Fill out this anonymous form. All questions will be published anonymously.

As of Election Day 2020, 1 in 3 Americans live in a state where adults can legally buy cannabis. Here's what we know about the drug.