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What Are the Side Effects of High-THC Cannabis?

August 4, 2016

Like virtually all medicines, cannabis can induce its own unique set of side effects. Although not everyone’s experience comes with a side of adverse reactions, it’s worth knowing what you may be at risk for, especially if you’re a new user. Keep in mind, these cannabis side effects are caused by its main psychoactive ingredient, THC (we’ll get to the side effects of other cannabinoids in future articles). Although this list doesn’t include all side effects of THC, it cites the most commonly experienced.

How to Avoid the Unappealing Effects of THC

There are a few ways to help you dodge the not-so enjoyable effects of THC:

  • Try a strain that is high in CBD, like ACDC, Cannatonic, Harlequin, or Canna-Tsu. CBD is not psychoactive in the same way as THC, and it can help curb the side effects of THC for a more relaxed, mellow experience.


Which cannabis strains are high in CBD?

  • Start with a very low dose when using high-THC strains. Adverse side effects tend to set in with continued or heavy consumption, so start with just a puff or two and see how you feel. You’d be surprised how much fun you can have with minimal amounts of cannabis.


Less Is More: Why Low-Dose Cannabis Is Important

  • Consider using an oil-filled vape pen if you’re sensitive to smoking or edibles. These allow a great deal of dosing control with mild effects, which has made them incredibly popular choices among newbies and older generations jumping back into cannabis.


Which Type of Vaporizer Best Suits You?

  • Start with a 5 mg dose of edibles if you’re unaccustomed to THC. From there, you can slowly and responsibly work your way up in dosage if the effects are mild.
  • Drink lots of water while using cannabis. Hydration is key to avoiding many unpleasant side effects.

Potential Side Effects of High-THC Cannabis Strains

Here’s a breakdown of the potential side effects associated with high-THC cannabis strains.

Paranoia and Anxiety

potential high-thc marijuana side effects: paranoia and anxiety

One of the worst side effects of THC is anxiety and paranoia. Though small amounts of THC are likely to only induce mild paranoia or social anxiety, edibles and large doses can cause exaggerated side effects (just ask the guy who ate an edible and called 911 because he thought he was dying). THC is known to relieve anxiety in smaller doses and increase it in larger; this is due to its biphasic effects, meaning it can have two opposite effects in high doses. Furthermore, some people are genetically predisposed to experience anxiety with cannabis as a result of brain chemistry.


Can CBD undo the anxious side effects of THC?

If you do find yourself susceptible to cannabis’ anxious effects, definitely give some of the above tips a try – CBD strains are amazing anti-anxiety solutions, even after the fact! It also helps to only consume when you’re in a comfortable place, such as at home or with friends.

Dry Mouth

potential high-thc marijuana side effects: dry mouth

Better known as the dreaded “cottonmouth,” high-THC cannabis can also make your mouth drier than the Sahara Desert. Believe it or not, there are cannabinoid receptors in our saliva glands. THC mirrors a naturally occurring chemical called anandamide, which binds to these receptors to decrease saliva production. THC, with its high affinity toward these receptors, exaggerates that effect much to our dismay.


5 Things That Are Chemically Similar to a Cannabis High

Remember to dose low and keep plenty of water (and maybe some chewing gum) on-hand in the event that cottonmouth strikes.

Dry, Red Eyes

potential high-thc marijuana side effects: red eyes

Not only does THC cause the mouth to dry out, it can also cause dry, red eyes. It’s the classic, telltale giveaway that has made eye drops a natural companion for discreet cannabis consumers. But what causes it, and are eye drops the only cure?

It may be, in part, due to the fact that smoke can irritate the eyes, but other consumption methods can also cause dry, red eyes. THC is known to lower blood pressure and dilate blood vessels in the eyes, leading to redness. Though less likely, an allergy to cannabis can also cause red eyes.


Why Smoking Cannabis Causes Red, Bloodshot Eyes

To counter these side effects, pump the water and stay hydrated. Eye drops can be helpful if your eyes are irritated, but avoid relying on these every time, as some brands can actually cause dryness afterward if used continually.

Hunger and “Munchies”

potential high-thc marijuana side effects: the munchies

Unless you have an underactive appetite, you might consider the munchies a nuisance and side effect of THC. Because it stimulates areas of the brain associated with appetite, THC can jumpstart a fierce hunger that may or may not motivate you to order the entire left side of the Taco Bell menu.

Curb this side effect with high-CBD or high-THCV strains.


The Science of Munchies: Why Does Cannabis Stimulate Your Appetite?

Sleepiness and Lethargy

potential high-thc marijuana side effects: sleepiness and lethargy

Once again, this “side effect” is seen by some as a therapeutic benefit as THC fights insomnia and promotes rest. However, if you’re looking to stay active while using cannabis, bear in mind that some strains can induce naps, lethargy, or an early night’s sleep.

Indica strains have long been associated with sedative effects, so we recommend sativa or high-CBD strains for daytime use. You may also consider trying a cannabis-infused coffee or tea, or pairing them to help lift out the lethargy.


Cannabis and sleep: 9 things to know about your herbal nightcap

Impaired Memory

potential high-thc marijuana side effects: impaired memory

Although memory impairment tends to be less of a problem for those well-accustomed to new consumers, it can be an annoying affliction to many. Luckily, memory impairment associated with cannabis appears to be temporary, but even short-term effects can get in the way of a productive afternoon and cognitive tasks.

Once again, high-CBD strains are a wonderful alternative for anyone looking to keep their memory and cognition intact. Supplements like gingko biloba and B vitamins may be helpful in countering these side effects, but your best bet for maintaining cognition is dosing low and slow.


How Does Cannabis Affect Your Memory?

You may experience a number of other side effects with cannabis such as headaches, dizziness, and respiratory difficulties, although these are less common. It’s always a good idea to communicate your cannabis consumption with your doctor in case it interacts with another medication you are taking. Because its side effects tend to be mild, many patients prefer it to other medications, but familiarizing yourself with any and all risks is the best way to ensure a good experience for yourself and the loved ones you’re enjoying it with.

  • Great Post! I’m a big fan of Jack Herrer for anxiety. Can you do a post on why some Sativas are good for anxiety, when in reality they shouldn’t be.

    • DrAnna Nordin

      Jack Herrer made a patient of mine visualize a sink hole in their bedroom! So many different reactions to the same strain! This concerns me.

  • Marie Clarens

    Good read, I think this post is honest about detailing the side effects of medical marijuana. Although the list is also long I think the side effects of taking regular drugs such as pain killers and anti-depressant is even longer thus I am still in favor of the use of medical marijuana.

    Its all over the news there was a forum last month held in New York and many investors and famous personalities like Eugene Monroe, Steve De Angelo, Troy Dayton, Jean Sullivan and Richard Kimball were in attendance this proves that the marijuana industry will soon thrive despite of diverse opinions regarding its use.

    Full article here:

    • Suzanne Marie Tucker

      This post is not that honest at all about the so called side effects and gate way drug bs, because there is little to none, there is no withdrawal symptoms from cannabis other than lifting up your mood and making you relaxed… It is a no brainier for most people a nd it really does help the people who use it or they would not be smoking the wonderful green plant from mother nature, not synthetic like these big drug companies keep making and knowingly killing us with their poison.

      • Josephine L LaGreco

        Amen to that

      • yeltommo

        Black-and-white thinking much? You’re full of shite if you think cannabis has no negative effects or withdrawal symptoms. I have personal experience with both, and I’ve read scientific studies of both. I’m not against cannabis use in any way, but it’s clear you’re living in an echo chamber.

  • SJHM7Ltl7LiZf2SvhmsTPQkUEWk9jZ

    Has the oil ever been known to cause diarrhea?

    • Suzanne Marie Tucker

      No it does not cause diarrhea…

    • This is library

      It DOES cause diarrhea don’t let the main stream media sway your opinios

  • Suzanne Marie Tucker

    A lot of the information is incorrect listed in this article and most people don’t know any better so they believe the hype?!? above all, I know quit a bit about cannabis after a lot of research and it does not cause anxiety and extremely high doses of THC can cause paranoia for people who have mental health issues; more specifically Schizophrenia! It helps relieve anxiety and depression, that is why people use it, to self medicate because there are no withdrawal effects like with alcohol and opiates… In fact any one who uses alcohol or puts there kids on stuff like add medication that is designed for adults are hypocrites, because alcohol and opiates is what is wrong with this country. Furthermore those things we give our kids today for hyperactivity are far worse and more lethal than cannabis could ever be…That is a fact…Giving a pill for every ailment is an epidemic and does more harm than good…Food for thought…

    • olive42

      I am a user of cannabis oil myself, but I’m starting to see a bit of a problem with the way some people use it. For example, I guy I know has a scrip for 10 g a day, and he says it’s not enough. He also feels it’s safe to drive when he’s using. He’s become really paranoid and flighty, which he never was before.

      . The really odd thing is that he told me how he has social anxiety, and any time he feels anxious, say for example when he’s shopping, he doses himself with the oil beforehand, and in a couple of minutes, he’s fine.
      I don’t claim yo be any sort of authority, but I think he might have bit of the placebo effect going on .

      • alex adam

        No placebo effect going on Taking a hit of oil is like smoking a cigarette You get the lift for awhile then it subsides Its Not a forever effect thing

    • yeltommo

      Agenda much?

  • Nathalie Burnett

    How to sensibly buy LEGAL cbd oil online? Because I got a letter saying customs has confiscated my package two times already and I’m pissed.

    • alex adam

      If your buying CBD oil from a reputable dealer obviously something isnt right here What Customs agency in confiscating your purchases You need to contact them What they are doing appears to be illegal

      • JinxTheMighty

        Federal regulations on cannabis are different from those of states, even states who have legalized the sale and usage of cannabis products. Cannabis is still considered an illegal controlled substance according to Federal regulations.
        The US Postal Service is a Federal institution. Even using private shipping across state/international lines imposes Federal jurisdictional authority. Your best bet is to research and find a suitable, reliable source locally… at least within your own state.

  • olive42

    I’ve used the oil for about a year ( less than the equivalent of a gram a day) for pain. It works well, but I started losing weight, have horrible night sweating, feel sick all the time, etc. My doctor suggested I do a trial run for a month an see if these symptoms go away. If they don’t , it could mean I have cancer or sarcoidosis. I am so tired all the time now, and , if you’ll pardon a four letter word, I feel like crap ll the time, and it sems the il may have been covering up some other symptoms as well.

    • Dmember

      Sure hope you can figure out what’s wrong and get better soon! God bless.

    • alex adam

      Search out Cannabis and introduce it into your life The right strain is out there for you

    • anne0

      Hope your doing well. If you don’t mind, what was the oil you were using that caused you to have “Night Sweats” ?

  • DrAnna Nordin

    THC also lowers testosterone in men. (cite: NIH studies). it appears most commentators are confused. They are equating THC and cannabis as being one and the same, when THC is only 1 of 12 drugs in the cannabis plant. The article is about THC, not cannabis. Before you get judgemental, I am a doctor who certifies people for MMJ cards. I have read over 27,000 studies. High CBD low THC strains have no harmful effect, but high THC strains do. Everyone, please stay on topic and do your homework. I have had patients develop psychosis from long term THC use.

    • Lithe Lassie

      What do you consider long term use? I have a 17 y.o. who secretly used vape pens (2) over a period of 3 1/2 months, nearly daily usage, and then had a portion of one 80 mg brownie and had a very bad reaction. She threw the rest of the brownie away. I have just discovered all this 5 weeks after the fact. She stopped all vape and edible use after the bad reaction to the edible, but has been experiencing bad anxiety, derealization, existential anxiety, and had a couple of panic attacks. We saw a psychiatrist yesterday who said the THC could still be in her system 🙁 🙁 She has been prescribed Lexapro and therapy. I am concerned about long term effects. She is an honors student who got into several very good colleges, her dad and I are so dismayed for her that this is happening.

  • Lisa

    Has anyone encounter a increase in hair loss?

  • DrAnna Nordin

    Over the past year in Arizona, it has been virtually impossible to get low THC/high CBD strains, irregardless whether they are indica or sativa. I was told that due to demand, the growers only supply high THC plants. I don’t use marijuana but the gentleman I live with does and wants to use high CBD/low THC but can’t find it. The dispensaries don’t label the %s of each in the plant, so he is at the mercy of the dispensary as to what they tell him they are giving him, which is high THC/low CBD. I am getting panic attacks from the second hand smoke. This is unacceptable.

    • MJ Brennan

      I need low THC because it effects me badly but need it for the arthritis pain. I found a really good CBD oil from Buddhafarms (Arizona) that helps my fibro pain so I just purchase the THC oil at the dispensary and add 5 – 10 drops for the arthritis pain.

  • DrAnna Nordin

    makes me wonderful why anyone in their right mind would want to use high THC cannabis…..

  • viper643

    TINNITUS. I developed this condition after exposure to high frequency noise in my profession. My brain has taught itself to ignore or push the noise into the background. When my neurologist prescribed Percocet for a cervical neuropathy that caused pain in my neck and shoulder; it had minimal effect and caused sheet soaking night sweats. When my state permitted MMJ for chronic pain ; I began using cannabis a year ago. It surprised me how effective the CBD/THC reduced that neuropathy pain. The side effect was a pronounced increase in the tinnitus amplitude. Maybe my brain cannot combat both problems at the same time; but I’ll gladly take the pain reduction. Honestly believe the pain reducing effects of cannabis are located in the synapse network of the brain. Not a CURE by any means; just an improved quality of life.

  • Lithe Lassie

    Am glad concerns about marijuana’s ability to cause anxiety, paranoia, panic attacks are finally being addressed. It seems with high dose THC this is so much more likely. I do not use cannibis because of this. It’s scary for those people who want to use it for pain or just low dose to relax and find they have taken a high dose cannabinoid that gives them very adverse effects.