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Health

Is Neem Oil Causing Cannabinoid Hyperemesis Syndrome?

June 24, 2019

Cannabinoid hyperemesis syndrome (CHS), a rare cyclical vomiting condition, is said to be triggered by too much cannabis. But many believe this isn’t true—and instead say the painful bouts of vomiting come from other factors, such as pesticide contamination.

Recently, the idea that neem oil (a very common pesticide) could be responsible for CHS has become a popular theory.

But is this theory plausible? While plenty of rare allergies and sensitivities to cannabis certainly exist—and some say that neem oil is the most likely cause—medical experts and CHS sufferers have concluded the theory simply doesn’t hold water. So what is the cause of CHS?

Cannabinoid Hyperemesis Syndrome Defined

Doctors first identified cannabinoid hyperemesis syndrome in 2004 when a new set of symptoms starting showing up for some cannabis users.

These patients came to emergency rooms complaining of recurrent episodes of intense nausea, vomiting for hours, and unusual body temperature shifts. Prolonged vomiting dehydrates the body, and in rare cases can lead to death from kidney failure.

Strangely, for all of these patients, the symptoms could be relieved by taking hot baths or showers.

Blood toxicology showed no drugs in these patients’ systems, other than cannabis. Most sufferers used large amounts of cannabis daily—grams of extract per day, or several ounces of flower per month. So doctors suspected heavy use might play a role, and recommended stopping use entirely to see if that helped. Most of these patients stopped their use and had their symptoms subside. But those who continued using cannabis, continued to be ill.

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Real or Not, Cannabinoid Hyperemesis Syndrome Is a Costly Diagnosis

Suddenly CHS was a thing. Even if the mechanism wasn’t fully understood, there was a clear profile of symptoms that was unlike anything else.

By 2012, more cases of CHS began to appear in the medical literature. While it is considered extremely rare, the exact numbers are hard to pinpoint. Some experts like Dr. Ethan Russo note there are around 200 identified cases of CHS in the world, “but it is much more common than that.” For example, there are online message boards and Facebook groups dedicated to CHS with thousands of members who believe they may have this condition.

A Neem Oil Theory of CHS Emerges

Despite the association between stopping cannabis and CHS symptoms going away, many remain unconvinced CHS can be a reaction to cannabis overuse. Some argue that the condition is actually the result of pesticide poisoning—specifically from neem oil, a pesticide commonly used by commercial and home gardeners.

Neem oil is deemed an “organic pesticide” as it comes from the vegetable oil of seed kernels from the neem tree (Azadirachta indica). Neem oil contains active ingredients like azadirachtin, nimbin, picrin, and sialin.

This theory gained prominence through CHS patients like Taeia Kaley-Dolan, who started doing her own research on the syndrome and noticed similarities between the symptoms of CHS and poisoning from azadirachtin, one of the chemicals in neem oil. Both CHS and azadirachtin poisoning can cause severe vomiting and nausea. However, azadirachtin poisonings are rare and symptoms also include not just vomiting, but seizures, acidic blood, and deadly nervous system swelling.

Kaley-Dolan shared her theory to help others with her condition understand that it might not be from cannabis, and many in the cannabis space echo the theory that CHS might really just be pesticide poisoning, or something—anything—other than cannabis.

Related

Should You Fear Pesticides on Your Cannabis?

Cannabinoid hyperemesis syndrome is sort of like the boogie man for cannabis consumers. It comes without warning and turns your ideal medicine into your worst nightmare, but it’s also rare, so many have never met someone with the condition. It’s no wonder that the cannabis community pushed back on this theory, saying it must be misdiagnosed or totally made up.

Russ Hudson, a Barcelona, Spain-based cannabis consultant who has been working in the space for 27 years agrees. “I would posit that most veterans in the cannabis industry—people with 20-plus years of experience—think that cannabis hyperemesis is a made-up or severely ‘misunderstood’ (read; misdiagnosed) condition,” he shares. Hudson says that he’s never met anyone with this condition in his entire time working in the space, and isn’t sure it’s real.

According to Hudson, “Azadirachtin poisoning seems a likely culprit, as well as other types of contamination,” such as bacteria or other pesticides. He also points to allergic reactions to terpenes or an uncomfortable reaction to being too high as potential causes.

Registered nurse Doug Rhodes is a wellness educator who has seen two cases of CHS first-hand agrees with Hudson and Kaley-Dolan, saying, “I’m a firm believer that hyperemesis syndrome is from contamination, be that neem, pyrethrum, or other products.”

So could it be that CHS isn’t a real thing? Could it be that we are just seeing pesticide poisoning and there are no cases of true CHS—cyclical vomiting actually caused by cannabinoids?

Unfortunately, this theory doesn’t line up with the evidence.

Neem Poisoning Differs From CHS

While we’d all love to hear the news that CHS could be solved by avoiding neem oil, the medical experts we talked to say this theory doesn’t make much sense. The effects of these two conditions are just too different from each other.

“As much as I decry the use of pesticides on cannabis, their toxicity profile does not match the symptom complex or time course of CHS.”
Dr. Ethan Russo, cannabis researcher

“As much as I decry the use of pesticides on cannabis, their toxicity profile does not match the symptom complex or time course of CHS,” explains leading cannabis researcher and neurologist Dr. Ethan Russo. “Neem oil and azadirachtin generally have limited human toxicity, but can rarely produce vomiting (the only symptom in common with CHS).”

Dr. Russo points to the other symptoms of azadirachtin overdose like increased salivation, diarrhea, liver toxicity, and convulsions. “The latter symptoms do not match CHS at all,” he says. “This is someone’s wishful thinking, or just another conspiracy theory.”

Furthermore, neem oil poisoning cannot be treated with hot showers, a core feature of CHS.

Jeff Raber, PhD, a cannabis researcher and organic chemist, agrees that neem oil isn’t likely to be the culprit.

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“Someone sent the neem oil link to me a while ago and I was just like, ‘It doesn’t make that much sense,’” he recalls. “A lot of people use neem oil on that and on a lot of other products. We don’t see neem oil hyperemesis syndrome. I think we’d see a lot more cases because of the prevalence that neem has been used.”

These experts say that the CHS cases they’ve encountered and studied seemed to consistently respond to one major factor: cannabis use. They both believe that an overabundance of cannabinoids is causing nerve cell signalling dysfunction. The theory comports with what’s known about cannabis, based on cell, animal, and human trials. Take vomiting, for example. At low doses, cannabis can treat nausea. But at high doses—the opposite occurs.

“Phytocannabinoids such as THC are noted to produce biphasic effects, i.e., they may produce one effect at a low dose and an opposite effect at a much higher dose,” explains Dr. Russo. “THC is normally antiemetic, but perhaps in CHS this reverses after heavy chronic usage.”

Scientists know THC stimulates the body’s CB1 receptor—found in the brain and the gut. The body responds by decreasing the number of CB1 receptors on nerve cells. That’s how tolerance to THC develops. If the number of CB1 receptors falls below a certain threshold, boom, hyperemesis, scientists think.

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Another factor is the TRPV1 receptor, also known as the capsaicin receptor or the vanilloid receptor 1. This receptor seems to be involved in CHS, and is activated by cannabinoids. Issues with TRPV1 could explain why hot baths help, since they are also known to activate that receptor.

Still, what’s not clear is why this condition affects only a small subset of cannabis consumers.

While both doctors said more research should be done to understand this rare condition and the exact mechanisms driving it, both were also convinced that pesticides could not account for the symptoms seen in CHS.

Patients Get CHS From Clean Cannabis

Perhaps the biggest nail in the coffin for the ‘CHS is just pesticide poisoning’ theory is the fact that some patients have gotten CHS from cannabis that was grown without pesticides, including neem oil.

“You can have too much water. So why are we trying to pretend that you can't have too much cannabis?”
Alice Moon, CHS sufferer, Los Angeles

Take Jared Panks for example. The 39 year-old is a co-owner for Home Grown ORegonicX, a company in Oregon that teaches deaf individuals how to cultivate cannabis. He sources cannabis from his own organic garden, which is pesticide-free (including neem). So when he was diagnosed with CHS, he knew that pesticides couldn’t be the reason.

“I have all this documentation with all the genetics that I’ve grown, all the mold tests, all the pesticide tests, all that stuff, and I’m still getting sick,” he explains.

Panks’ symptoms line up perfectly with classic CHS—cyclical vomiting that increases with more cannabis use, and is relieved by hot baths and cannabis cessation. Panks’ worst attack left him unable to hold down food or water for 14 days. He needed to be hooked up to IV’s to survive the severe dehydration.

“For me, I think it’s an overload on cannabinoids,” he explains, adding that he’s tried cannabinoids other than THC, like CBD and CBN, and still had bad reactions. The only thing that has helped is lessening his intake of cannabinoids. “They can’t clinically say that anybody’s ever overdosed from it,” he adds. “I can say that I’ve overloaded. And that’s the truth.”

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Alice Moon, a 29 year-old from Los Angeles with CHS, says she is also convinced that pesticides are not the problem. She put her body through the ringer hoping that pesticides might be.

The cannabis public relations person was once a cannabis edible reviewer, but had to shift her career focus when she discovered her recurrent vomiting would only stop when she ceased cannabis use. After quitting, her symptoms subsided and Moon decided to try again.

“I started smoking pesticide-free weed because so many people say CHS is pesticides,” she explains. “But I smoked pesticide-free weed and my symptoms came back after a few months.”

Her last attempt was to use hemp-derived CBD from a source she knew used no pesticides including neem. But one day, a larger than normal CBD dose sent her back to the hospital with her worst CHS bout yet—16 days of non-stop vomiting.

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“I had so many moments where I was wondering if I was going to die because it was so severe,” she recalls. By the end of her stay she had three ulcers, a hernia, and a bacterial infection from the experience.

“Now, I will not be a guinea pig at all,” she explains. “I can’t do it. My body can’t do it.”

Since her own failed experiments getting rid of CHS without stopping cannabis, Moon has been outspoken about CHS and her belief that it is truly related to cannabinoid intake. “I 1,000% believe it’s not neem,” she says, adding that she even had a blood test that came back negative for any pesticides.

“I do believe people can have pesticide poisoning. I am not denying that that’s real,” Moon says. “But I do think that this isn’t that.”

Moon says that since going public with her thoughts on CHS, she’s gotten a lot of negative responses from the cannabis community.

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“I get so much online hate in regards to this,” she explains. “Every other day, people are telling me, ‘You made this up. You work for the government. You work for Big Pharma.’ I’m like, ‘No dude, I just want to be able to smoke weed again.’”

Moon says she believes in the medical benefits of cannabis but wants to educate people about CHS so they’ll stop as soon as they exhibit symptoms and not risk their lives thinking pesticide-free cannabis will help. But Moon says, “People don’t want to believe it’s real.”

“You can have too much water,” she points out simply “So why are we trying to pretend that you can’t have too much cannabis?”

Are Sub-Populations Sensitive to Pesticides?

While the bulk of CHS sufferers must reduce their cannabis intake to be cured, some rare sub-groups most certainly have CHS-like symptoms related to cannabis’ many added ingredients. One such person is Leafly’s own Natalie Bernstein, a performance improvement analyst.

“It’s really difficult to say that any one answer is going to apply to everybody.”
Natalie Bernstein, neem allergy sufferer, Seattle

Bernstein moved to Washington in 2014 to use cannabis to manage her chronic migraines. In the spring of 2017, she switched from a pesticide-free, illicit market source of cannabis to store-bought cannabis. By summer of 2017, she developed what she thought might be CHS—nausea and intense vomiting following cannabis use.

While she worried she had CHS, her symptoms didn’t line up. She wasn’t a heavy smoker. And hot showers didn’t stop the vomiting. Rather, the antihistamine Benadryl controlled her nausea, she discovered by accident.

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Bernstein has many allergies, and new ones can pop up seemingly out of nowhere. Suspecting a rare type of cannabis contaminant allergy, Bernstein started tracking her intake. To source neem-free cannabis, she used Washington state’s cannabis industry pesticide application data, and called growers directly.

She found a strong correlation between inhaling flowers treated with neem oil, and her nausea and vomiting. “My doctor told me that I was wrong, that it was THC, so I stopped seeing that doctor,” she said. “People say neem is ‘organic,’ but poison ivy is organic.”

By winter of 2017, she determined she could control her nausea through edibles, or inhaling neem-free cannabis.

Bernstein believes not all CHS cases are caused by heavy cannabis use. There’s probably a spectrum of CHS causes, where maybe 70% of CHS sufferers might have classic CHS, she believes, while maybe 20% have a reaction to pesticide toxicity, and 10% have rare allergies to even trace amounts of pesticides, like her.

“It’s really difficult to say that any one answer is going to apply to everybody,” Bernstein said. “I think what I have is more prevalent that what people know.”

Related

Allergies Buggin’ Out? Cannabis Can Help, or Hurt

Neem Oil Generally Not Causing CHS

So is neem oil the cause of CHS? Generally not. The bulk of early evidence points to overactivation of the CB1 receptor. The old adage “moderation in all things” holds true.

There is a long way to go in understanding CHS, and why it only affects a segment of heavy cannabis consumers. More research is needed to fully understand what factors are at play in this mysterious condition.

Still, while we’d all love to hear that CHS is just a made up condition or a misdiagnosis of something we can easily fix, the pesticide theory doesn’t match most case studies. Patients like Moon and Panks are suffering from a very real condition, one that can’t be explained by pesticides.

When pesticides are taken out of the equation, CHS remains.


Lead image: calvindexter/iStock

Emily Earlenbaugh's Bio Image

Emily Earlenbaugh

Dr. Emily Earlenbaugh is a cannabis writer and educator. She is the Director of Education for Mindful Cannabis Consulting, where she teaches patients how to find the cannabis options that work best for them. She regularly writes about cannabis science and culture for publications like Cannabis Now Magazine, SF Chronicle’s GreenState, HelloMD, and Big Buds Magazine. Emily has a doctorate in philosophy of science from UC Davis.

View Emily Earlenbaugh's articles

  • James Lake Rackstraw

    I would give anything to be able to smoke again. I just can’t take the pain… I think that my next joint would be my last.

    • Mark Rauser

      I have chronic pain and it works…..so I have been told. And the MM Dr. Said if anything it helped lung cancer per 15 year 2x blind study at UCLA

  • Christine Leary

    Good article but didn’t mention that symptoms of neem poisoning only resemble those of CHS when SWALLOWED. Symptoms of inhaled neem poisoning are limited to lung irritation.

    • E.L. Bl/Du

      I politely disagree with your theory and heres why. Lungs are VERY vascular, and whatever you inhale absorbs into the blood stream very quickly from the lungs. Quicker than from the stomach. Thats why it takes longer when you take edibles rather than smoking. Gets into the bloodstream faster actually. Not as fast as IV or Intrmuscular injection, but faster than via stomach. I hope that makes sense.

      • Christine Leary

        It’s not a “theory.” If you obtain your data on the subject from a pesticide publication instead of one of the many weed publications that adopted this theory you would understand.

  • Ted Hundley

    I smoke no more then 1 .gr of flower a day. Sometimes with dabs added. I have never thrown up after using any cannabis product. But I do feel sick to my stomach a lot. Have had my gall bladder out. But my mom did to in her cannabis free life. I guess I’m still hoping….

  • Michael McCallum

    after seeing someone close hospitalized numerous times due to CHS, its infruriating to see the doubters and supposed experts discredit it. we also believed it could be a contaminant, but it was usuaoly high quality concentrates so pesticides carrying over and surviving extraction seemed highly unlikey. stopping was the only thing to stop her week, sometimes 2wk, of vomitting.

    • MyNameIsTaken

      Some people on here posted about hot peppers stopping the symptoms.

  • Mark Rauser

    Trysophate is the reason enough to make all crops organic. It’s used to spray most all food. It’s poisoning us . Tell Congress to ban this chemical Now

    • E.L. Bl/Du

      ????? What are you referring to, this “Trysophate” doesnt exist in google

      • Mark Rauser

        I maybe spelling it wrong but it’s very real.

      • Mark Rauser

        Glosophate, not sure on spelling but people are trying to get the poison that is sprayed on most crops that are not organic

      • Mark Rauser

        Glosophate sorry fat fingers

  • Richard Morris

    Smoked 43 years everyday. Never got stomach unless mix booze with it. Grow your own n know what is used on it. Organic is my way I go

  • P.J. Rafter

    I find it strange that there is no mention of CHS in the literature?

    And cannabis-smoking’s been around long enough to spot something like that…

    Something else is going on, I think?

  • Ed Joyner,Jr

    Thank you for an insightful article about CHS! Sadly from my experience it is definitely not a made up syndrome! I had the early symptoms and couldn’t understand what could possibly be the cause? Incredible abdominal pain with nausea and vomiting was a powerful motivation to try and figure out the cause! I accidently stumbled on an article about CHS and the facts all fit what I was experiencing! I was intrigued to read about the apparent connection with the TRPV1 protein and the relief provided by hot showers and the application of capsaicin( from hot peppers) applied topically to the skin! However, it seemed like a no brainer to me to put it more directly on the problem! I took 3 tablespoonsfuls of the hottest pepper sauce I had available and the relief was almost immediate(3- 5 minutes!) and it prevented any symptoms for about 24 hours! Since then any time I have a flare up a few tablespoons of hot sauce cures all the CHS symptoms! It is a cheap and highly effective way to knock out CHS and allow me to continue smoking cannabis for my chronic pain and anxiety! The only side effects of the hot sauce is sweating profusely and mouth/lips burning for a brief period of time! Try it and I think you will be amazed and pleased about how well it works!

    • James Lake Rackstraw

      I found the same thing, I believe taking capsaicin internally to be more effective than topically.

    • 1st World Problems SOLVED

      It’s real regardless of the root cause (thc/terpene overdose or neem oil contamination) and this hot pepper sauce remedy works for me as well…I came to the same conclusion as well…this assumption derived after reading about the TRVP1 v. receptor in med papers and the use of capsaicin in the ER by that one Dr. as well…That being said, dehydrated raw pepper bits, black peppercorns (slow breakdown), Habanero sauce or Jelly (if you need sugar also) all work excellent and seeming provides quick and long term relief; liquids can be loaded into a syringe to bypass most taste buds if desired. I use the El Yucateco brand green personally. Also increasing H20 intake (add some lemons/limes helps, if you don’t enjoy drinking straight water) as well as get some healthy sugars if you have low blood sugar; being dehydrated and low on blood sugar seem to amplify/induce the more extreme effects. My theory; A genetic defect exists that even allows this to be a possibility for certain people, seeing even suffering CHS is rare, this could likely same gene that allows familial pancreatic cancers as that also is alleviated through TRVP1 stimulation (med papers).

  • Jim Trebowski

    I’m currently taking a month long break after four bouts that occurred every six months. Hoping to be able to resume using lower doses after, but if it happens one more time, I guess that’s it.

  • Capt.Steve Thompson

    NEEM is not a culprit. I grow in Vermont to a 100% Organic Standard and use neem and soap as my only insecticide. The rule of thumb is not to apply NEEM 2 weeks before harvest–other than that no issues. People need to thoroughly test their soil as hemp/cannabis is a great phytoremediator.

  • Serai 1

    And in ride the internet doctorates to pooh-pooh the information. Denial, denial, denial. Damn, true believers are ridiculous – AND dangerous.

  • Mcozy333

    adipose tissue , leptin , Grhelin = all of those are effected by cannabis… most likely any upchuck issues could involve how phytocannabinoids effect those hunger responses

  • Matt kovarsky

    Dr. Ethan Russo says that it’s the biphasic effects of THC. in low doses THC can be anti-emetic, when you take WAYYYYY tooo much it can be pro-emetic. i wanted it to be Neem, but what Dr. Russo says goes

  • elbldu

    I read your attachment. This discusses inhaling the mist of the spray. NOT SMOKING it after a plant has been sprayed. Neem is very unstable and dissipates in 3-4 days to an Inert substance. There are chemical co;s who put synthetic pyrethin in their neem products, which does NOT breakdown like neem. I think your issue may be due to something else. Commercial growers are under more pressure than private growers to use sprays, and not sure what the limit is on testing. Ive NEVER had any residual on my canna plants and dont spray within 2 weeks of harvest. Organic products are not necessarily SAFE….After all, snake venom is organic, but you dont want to ingest that right? Im retired from healthcare after 35yrs and a master gardener and grower for 20, organic gardening 28yrs. Im so sorry you are feeling sick, but I dont think neem is the culprit unless your grower is spraying day of harvest. It hangs for at least a week, long enough for the substrate to disipate.

  • JWebb

    Why are some people allergic to peanuts? Back in the ’60’s, I’d never heard of it or new anyone that had peanut allergy, or any nut allergy, for that matter. And all the kids ate peanut butter it seemed. Hell, it was a staple for school=provided lunches. My point is, in general, that maybe, just maybe, not everyone is sensitive to CHS.

  • kelly johnson

    I’m sure CHS is real, but much rarer and currently overdiagnosed in place of its sister disease cyclic vomiting syndrome (CVS). I also want more information regarding how they came to the conclusion that high cannabis was the cause. From the article all they mentioned was a positive correlation between level of use and symptoms. However, correlation doesn’t equal causation and increased use could be in response to nausea rather than vice versa. Also… CHS SYMPTOMS AND CYCLIC VOMITING SYNDROME SYMPTOMS ARE ALMOST THE SAME!! CVS can occur in both children and adults and hot showers can relieve CVS symptoms too. CVS may have some connection to migraines. For something so ridiculously similar (with more scientific literature I might add) I’m surprised they didn’t mention CVS in the article. I guess it’s more convenient to ignore any explanation that doesn’t fit their narrative.

  • MyNameIsTaken

    Personally, I would not use need oil anytime close to harvest because I do not want it to get into my flavors. I also grow organic.

  • Michael Halliwell

    It’s really sad that a cannabis form has been overrun by fake ass “science”.