Who Cares About Marijuana Side Effects, Right?

Marijuana Side Effects

Let’s be honest — the use of cannabis is peaking. Recreational puffs thrive in popularity, medical use is blooming, and marijuana stocks recorded the highest year-over-year revenue growth. Considering that this is a plant with strong psychoactive properties, are marijuana side effects on the rise as well?

After almost forty years of illicit drug stigma, marijuana use is going through a new renaissance. Drug decriminalization, legalization, and its medical potential have put it back on the media pedestal.

This article will help you gain a much better understanding of what the true downsides of smoking marijuana are, how often they occur, and how long they last.

So, let’s dive right in!

Quick Stats and Facts on Marijuana Use

Since the introduction of the many health benefits of marijuana to the public, the illegality of the plant has been heavily debated. Today, consuming cannabis products is medically decriminalized and even legal in some countries. Due to its growing recreational and medical use, the side effects of marijuana are getting more common too.

Historical Statistics on Marijuana Use and Its Incline

  • 263 million people are said to use marijuana annually (2.5% of the world population).
  • A NIDA survey from 2018 states that 47.8% of Americans older than 26 have smoked weed at least once in their lifetime.
  • 13.3% of US adults used it at least once in 2017.
  • According to a recent study, cannabis-related emergency room interventions, between 2004 and 2011, increased by 43.1% nationwide. Here, the authors clearly accent the rising incidence of cannabis side effects.
  • In the state of Colorado alone, between 2011 and 2015, emergency room visits regarding cannabis increased by 130%.
  • In 2007, 2.1% of adults reported using marijuana for the first time. In 2018, this number increased to 10.1%.
  • In 2010, 21% of high school seniors used marijuana during the last month, which increased to 22.1% in 2018.
  • According to the DEA, about 40% of arrested males in 2017 tested positive for marijuana. The agency referred to this as the criminal side effects of cannabis.
  • According to the 2013 NSDUH data, the number of daily marijuana users in the US has climbed from 5.1 million in 2005 to 8.1 million in 2013.
  •  Research shows that the number of monthly marijuana users in the US increased from 14.5 million in 2007, through 19.8 million in 2013, all the way to 20.4 million users in 2015. Moreover, this number skyrocketed to 55 million in 2019 alone.
  • According to the poll from 2013, 76% of doctors were in favor of prescribing marijuana for medical purposes, with the emphasis on the proper designation of medical marijuana side effects.
  • WHO clarified that after tobacco and alcohol, cannabis is the third most used harmful substance on the planet.

Key Facts on Marijuana

There are three main types of marijuana plants. The most prevalent varieties are Cannabis Sativa (which includes industrial cannabis called hemp), Cannabis Indica, and less common Cannabis Ruderalis. There are many strains derived from the main two, including hybrids.

Here are some interesting facts:

  • The effects of weed are felt primarily by the central nervous system (CNS). All strains can produce a certain amount of psychoactive and neuroregulatory effects. In the long-term, there can be both physiological and psychological consequences. The potency of marijuana’s effects depends on the content of cannabinoids within the marijuana leaves and flowers.
  • The whole plant is considered non-toxic on its own and could be ingested. However, due to its low nutrition and digestive potential, it is mainly consumed through smoking. In this case, cannabis is preferably referred to as weed or pot.
  • Certain cannabis extracts, such as in butter or in oil, are used for culinary purposes. Today, cannabis dispensaries around the world have an assortment of cookies, brownies, butter, and chocolates that have marijuana extracts within.
  • The effects of getting high through vapor or ingestion depend on the level of absorbed cannabinoids. And here’s the tricky part — it can vary significantly. The main physiologically active compound in weed smoke is a phytochemical called THC (Δ⁹-tetrahydrocannabinol). The varieties of the plant contain different amounts of THC and related compounds.
  • CBD oil is a purified marijuana extract that contains mostly cannabidiol (CBD), a cannabinoid that has no psychoactive properties and is mostly used for medical purposes.

The originality and the duration of a marijuana high will depend on the final cannabinoid mixture within the consumed product. Some offer brief relaxation and tranquility, whereas others promise clarity, focus, and energy.

Negative effects of weed can vary depending on the amount of THC that is absorbed in the bloodstream, and on the frequency of consumption.

General Effects of Weed

Differing both on their botanical and agricultural preferences, marijuana plants can have diverse compositions, and produce a variety of symptoms. However, the main physiological and psychological effects of weed smoke are common for all strains yet can vary in intensity from one product to another.

Physiological Effects of Marijuana

When cannabinoids reach the bloodstream, it’s easy for them to cross the blood-brain barrier and influence cannabinoid receptors in the CNS. Weed’s effect on the brain and spine is the primary physiological event, which causes other, secondary organ system reactions.

Cannabinoid receptors alter neurotransmission within the CNS by influencing the activity of noradrenaline, dopamine, and acetylcholine. Depending on the primary cannabinoid binding site within the brain, marijuana can affect:

  • Coordination (cerebellum)
  • Learning and memory (hippocampus)
  • High cognitive functions (cerebral cortex)
  • Sleep onset and sleep quality (brain stem)
  • Senses (peripheral neurotransmission)
  • Sexual arousal (pituitary and limbic system)

Cannabis also impacts the Autonomic Nervous System (sympathetic and parasympathetic) that regulate automated functions, such as breathing, heart rate, and gland activity.

Most side effects of marijuana use develop as a consequence of this neural dysregulation.

Other typical effects of marijuana include:

  • Smooth and skeletal muscle relaxation — according to research, cannabinoids bind to spinal receptors and downregulate the muscle neurotransmission.
  • Cardiovascular depression — smooth muscles in blood vessels relax, thus lowering the blood pressure, and increasing heart rate (tachycardia).
  • Endocrine activity — dry mouth usually develops as an altered glandular activity.
  • Redness of the eyes and lowering of the eye pressure — result of both vascular and neural depressant effects.
  • Respiratory activity — versatile compounds in weed tend to onset a variety of lung reactions, which are also considered marijuana side effects.

Psychological Effects of Weed

They are the marijuana-user experience and are a combination of psychological background, emotional involvement, and neural dysregulation. Most common effects include:

  • Sense of euphoria, general well-being, and stress reduction
  • Increased appreciation of music and visual arts
  • Increased sensuality
  • Augmentation of tastes and aromas
  • Increased sense of awareness and creativity

Health Benefits of Marijuana

Marijuana uses go beyond recreational enjoyment. Today, purified strains are being developed and cultivated with the purpose of lowering the side effects of medical marijuana. Best CBD oil is also utilized for medical purposes.

Recognized Medical Effects of Weed:

  • Chronic pain relief (study)
  • Increment of lung capacity (study)
  • Insulin level regulation (study), used in diabetes and obesity treatments
  • Cancer therapy aid (study)
  • Appetite regulation, and anti-nausea remedy (study)
  • Treatment of mild depression (study)
  • Seizure control in epilepsy (study)
  • Glaucoma treatment (study)
  • Treatment of ADHD (study)
  • Mild anxiety and PTSD treatments (study)
  • Symptom relief and treatment of disease progression in neurodegenerative diseases, such as Alzheimer’s Disease (study), Multiple Sclerosis (study), and Parkinson’s Disease (study)
  • Digestive problems, such as IBS (study), or appetite disorders
  • Antirheumatic effects (study)

Regarding Side Effects of Cannabis

As mentioned before, both Cannabis Sativa and Indica have a multitude of strains, which can adversely impact the human organism. Their production is not always completely regulated, therefore the composition of one product may trigger a different reaction than that of another.

Medical marijuana, on the other hand, has a closely monitored production. Its strains are cultivated to produce an effect within the defined medical constraints.

CBD has a different receptor affinity and produces mostly positive effects. CBD oil side effects are less intensive than the ones that faithful pot consumers experience.

Whether natural or synthetic, marijuana side effects are tightly connected to their physiological and psychological activity. The intensity of these effects depends on the potency of the consumed product, including the frequency of use.

Recreational users usually focus on the lovely effects of weed smoke, thus neglecting the harmful effects that it carries. Medical users tend to stick to general compliance in the majority of cases, thus minimizing the incidence of adverse effects.

Development of Negative Effects

Acute use of marijuana is considered an isolated case, without repetition. It usually induces the main physiological side effects of weed, which can last up to 48 hours. In acute cases, the psychological component is mainly perceived as the “experience.”

In the case of chronic use, the body’s physiological response starts to change, and the augmented perception of reality influences the onset of deep psychological developments. Chronic users are defined as:

  • “Light” (one to four doses per week)
  • “Intermediate” (five to six doses per week)
  • “Heavy” (seven or more doses per week)

Depending on the frequency of use, marijuana can stay in the body anywhere between 3 days to 3 months.

Some side effects develop in the short-term and usually wither away during the following week of abstinence. Others, however, can create a long-lasting impairment.

The Most Prevalent Marijuana Side Effects

Cognitive Impairment

Smoking marijuana can significantly impact focus, memory, and learning, by interfering with associative processes in the hippocampus.

Acute cognitive impairment is mainly experienced as intellectual bluntness. It is expressed as the difficulty to recall things and perform problem-solving tasks, often referred to as “being stoned.” It seldom leaves any lasting consequences, other than a bit of amnesia regarding the event.

Chronic use, however, can lead to lasting or even permanent changes. According to the research, Cannabis Sativa effects on cognition were not associated with “light” and “intermediate” users.

On the other hand, “heavy” marijuana use is associated with deficits in mathematical skills, verbal expressions, and poor memory recall.

Long-Term Effects of Marijuana’s Continued Use on Cognition

Smoking pot in the pre-teenage period may seem cool, yet if it persists, it can produce a measurable impairment.

A study from 2012, which followed more than 1,000 participants for a period of 20 years, conducted a battery of tests on them, including neuroimaging and psychological tests.

The study found out that people who started using marijuana in their teens, and from then on maintained a relationship with weed, had a notable intellectual decline. Their average intellectual loss was about 8 IQ units. However, among “heavy” adolescent marijuana users there were no signs of significant cognitive decline.

According to the authors, these long-term side effects of marijuana’s enjoyment occurred due to the heavy impact of weed on the brain’s overall development during adolescence. It impaired their ability to learn, intellectually developed, and emotionally mature within this period.

On the other hand, a study on 789 pairs of adolescent twins showed that both the abstinent and the user twin had the same memory decline over time regardless of marijuana use.

Impaired Psychomotor Performance

One should not drive while high on pot!

There is a considerable number of effects of weed on physical coordination. According to research, human performance can be impaired up to 24 hours after smoking weed, with as little as 24mg of THC.

In acute users, this is mainly perceived as clumsiness or slow coordination. This happens due to marijuana’s effects as a muscle relaxant, contributed by divided attention and slower reflexes. Acute cannabis consumption is often associated with higher incidents of motor vehicle crashes.

Compulsive Vomiting

This is known as Cannabis Hyperemesis Syndrome, and it is common with “heavy” marijuana users. It is described as a state of cyclic episodes of intensive nausea and vomiting.

In lighter doses, cannabis has been proven to increase appetite and stimulate digestion. However, in chronic use, the brain receptors become saturated and can onset an adverse reaction. Some studies claim that these marijuana side effects are caused by the liver being overload with metabolites of weed.

Respiratory Problems

Breathe in, hold it, that’s the key.

It’s worth pointing out that smoking marijuana is an event concentrated in the lungs. Regardless of its unique aroma, cannabis can seriously irritate the lung tissue.

Phytochemical constituents of weed smoke act aggressively on the bronchiole. Acute use can result in cough, and chronic use is consistent with daily phlegm overload.

The evidence states that “heavy” consumption is associated with a higher prevalence of both acute and chronic bronchitis, compared to non-smokers. Other studies claim that side effects of synthetic weed include respiratory depression, which can be deadly.

The causes of the main respiratory side effects lie not only in natural marijuana compounds but also in their incineration products. These are ammonia, carbon monoxide, chlorine, polycyclic aromatic compounds, etc. “Heavy” marijuana use is also associated with the condition known as popcorn lungs (bronchiolitis obliterans).

Increased Heart Rate

This is an acute event. Marijuana can increase the heart rate for 20 to 50 beats per minute in mere seconds after inhaling, and these effects can last up to three hours after consumption.

People with heart conditions need to reconsider smoking weed as side effects can intensify arrhythmia, thus producing an unpleasant and potentially deadly experience.


The relationship between depression and marijuana is complex. It is known that underlying depression can cause an increment in marijuana use as a superficial remedy. However, there is evidence that positions recreational marijuana use as the cause of various depressive disorders.

“Light” use can be linked to depressive episodes, such as suicidal ideations, or short-term withdrawal depression.

Hard depressiveness is associated with “heavy” and “intermediate” marijuana use. Frequent neurostimulation can deplete the deposits of happiness hormones within the synapses. This usually causes hard abstinence symptoms and can lead to dependence.


This is one of the most common side effects of smoking weed. According to research, chronic marijuana use can influence the onset of mild to moderate anxiety disorder, without any connection to a preexisting individual or family background.

Chronic users often experience the relaxing effects of weed, which is followed by neural excitation. This is expressed as increased irritability, nervousness, agitation, limb restlessness, and sound hypersensitivity. It leads to amplified emotional experience and could result in allusions of fear.


Research shows that marijuana users have higher chances of developing temporary paranoia than the rest of the population. Although considered merely a “bad trip,” paranoia is one of the most common psychological weed side effects.

It is usually accompanied by feelings of anxiety and endangerment, often followed by changes in perception. Paranoia is fueled by negative thoughts and worry. It lasts until THC effects wear off, and is common both in acute and chronic use.

Psychotic Symptoms

It has been historically known that cannabis causes psychosis.

Acute use alters cognitive reasoning and can produce temporary hallucinations. Furthermore, a single dose of marijuana can induce a psychotic episode in predisposed people.

Epidemiological studies have proven beyond doubt that long-term effects of marijuana’s continued use include schizophrenia even in individuals with no previous history of the illness.

Behavioral Problems

When consumed consistently, weed causes deep psychological changes, which relate to the aforementioned psychogenic side effects.

Due to enhanced sensory experience and impaired cognition, “heavy” users tend to live with altered perceptions. Withdrawal anxiety makes it hard to flourish in social circles, which leads to psychological internalization and social withdrawal.

Chronic users often have relationship problems, mood swings, and in severe cases express antisocial behavior, such as vandalism and criminal problems.

Tolerance, Dependence, and Addiction

According to research, 9% of adults, and 17% of teens that use marijuana become addicted. This makes addiction one of the most serious marijuana side effects. Nevertheless, there is a difference between addiction and dependence, yet a lot of studies use the terms interchangeably.

“Heavy” users quickly develop tolerance. It is experienced as the rapidly fading effects of the common dose, which intensifies the cravings for repeated use. The brain mechanisms for tolerance include the internal downregulation of cannabinoid receptors.

Studies show that it takes several weeks of chronic marijuana use to build up clinical tolerance. Tolerance levels tend to decrease significantly after a week of abstinence.

Cannabis dependence syndrome develops in highly tolerant users. It is characterized by the presence of withdrawal symptoms during the period of abstinence.

The most common withdrawal symptoms include irritability, sleep disorders, and physical discomfort. Withdrawal peaks in the first week of abstinence, and usually passes after the second week.

Is marijuana addiction real? It is considered one of the most negative side effects of weed. Addiction per se is a severe state, and the user is considered an addict when they cannot control the consumption, and cannot stop taking it regardless of the consequences. Addiction is defined as a psychological state, not physical.

Addiction is more common in people with underlying psychopathologies, such as depression, anxiety, or psychosis. Behavioral psychology states that insecure personality types are more predisposed to addiction.

When it comes to the negative side effects of marijuana, addiction is better defined as cannabis use disorder (CUD). We prefer this term to marijuana, unfortunately, it is regarded as other Schedule I drugs, such as heroin, but it is far from it.

Sexual Impact

Throughout history, marijuana has been referred to as an aphrodisiac and the sexual experience enhancer. A recent study confirms these claims by stating that cannabis users have a higher coital frequency compared to non-users. Users describe marijuana as an orgasm-quality booster and an intimacy enhancer.

However, the side effects of weed can sexually impair a partner as well. The psychological effects of marijuana can lower a person’s libido by enhancing internalization and partner detachment. In men, this can often result in erectile dysfunction.

Side Effects of Laced Weed

Laced marijuana is enhanced with some other chemical, medication, or drug. There are several ways that one can combine weed with other substances, but the ones that are visually undetectable include spraying liquid forms.

Marijuana is mostly laced with LSD, PCP, coke, ketamine, fentanyl, heroin, opium, or crack. Laced weed side effects include a variety of physiological effects, which is a trait of the additional substance.

Additionally, the common experience is much stronger than that of regular weed. Depending on the mixture, the side effects include visual and auditory hallucinations, involuntary muscle spasms, excessive sweating, heart palpitations, distorted body feelings, etc.

Side Effects of Medical Weed

Medical cannabis is considered purer than its recreational counterpart and causes fewer side effects. However, the side effects mentioned in this article may apply to the medical strains as well.

According to research, side effects of medical marijuana’s use are red eyes, dry mouth, thirst, hunger, anxiety, paranoia, altered sensory perceptions, cognitive impairment, fatigue, diarrhea, constipation, respiratory issues, increased heart rate, hallucinations, slurred speech, tolerance, and dependency.

In the case of aerosol-borne infections, one may never be too careful as to refrain from sharing blunts or vaporizers. Infectious droplets, such as in the case of Coronavirus, linger on the mouth mucosa and could be transmitted this way.


Weed makes the time pass slower and deepens our focus. It empowers the feelings of love and relaxation. Marijuana makes music wonderful, and food a lot more enjoyable (and tasty).

Again, let’s be honest — it can help you sleep, but it can also bring out your worst nightmares. Long-term side effects of marijuana’s frequent use include behavioral and physiological consequences, and as such is a thing users should be very much aware of.

The best way to avoid negative effects is to control the procurement and use of marijuana products.

Recreational cannabis should be acquired through legitimate channels. This way, a weed consumer gets the product of defined quality, with appropriate THC levels. A variety of cultivated strains guarantee both effects and side effects.

Marijuana users should not only seek controlled products but should also stick to the compliance advice. Using more than what is prescribed often leads to dependency and various marijuana side effects, which can lead to the onset of other affiliate conditions.


Why is marijuana illegal?

The Controlled Substance Act of 1970 classified marijuana as a Schedule I drug, production, possession, and distribution of this plant in the US have been treated as a criminal act.

In the past few decades, however, many countries worldwide have decriminalized or legalized the use of cannabis. The reasons for criminalization were rationalized on the strong side effects of marijuana.

Does marijuana kill brain cells?

There seems to be no evidence that marijuana influences brain cell count in adults.

Nevertheless, some studies show that smoking marijuana in childhood and teenhood can permanently impair brain and personality development.

Still, more data is needed to fully assess the long-term effects of marijuana on the brain.

Does smoking weed cause cancer?

Weed smoke contains carcinogens similar to tobacco smoke. These components can cause lung tissue inflammation. Nevertheless, the cumulative effects of pure cannabis smoke on the lungs have been proven less harmful than when mixed with tobacco.

Components of marijuana smoke inhibit carcinogenic pathways that are essential in the development of lung cancer. In general, the side effects of marijuana use do not include lung or any other type of cancer.

What is a THC overdose?

It is possible to overdose on cannabis, yet there are no death records. The effects of high doses can produce an unpleasant experience, which includes: respiratory depression, headaches, uncontrollable shaking, vivid hallucinations, severe panic and paranoia, and in rare cases coma.

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