Actor David Krumholtz had a very serious reaction to a very popular drug: marijuana. 

The Numb3rs star, 46, started using marijuana again after ‘a long break’ and soon became ‘a daily smoker.’

He then developed a rare condition called cannabinoid hyperemesis syndrome (CHS).

‘It’s rare, [but] it’s becoming more and more prevalent yearly — like, numbers are doubling every year,’ he shared with Page Six at a screening of Riff Raff. 

He said there are ‘a lot of theories’ as to what has caused a spike in CHS, which only affects ‘daily long-term users of marijuana,’  but he thinks cannabis companies are to blame.

‘Essentially, they messed up weed,’ Krumholtz said. ‘They made it too strong, and they don’t know why it’s happening.’

In the United States, cannabis is legal in 39 of 50 states for medical use and 24 states for recreational use. 

Actor David Krumholtz had a very serious reaction to a very popular drug: marijuana. Seen here in February

Krumholtz won critical acclaim for his role in Oppenheimer

The Oppenheimer actor said the brain has, ‘cannabinoid receptors’ and ‘you can blow out the receptors, like blowing out an engine, making it that every time you smoke pot — not every time, but if you smoke it enough — you get wildly, dangerously nauseous.’

CHS ‘leads to repeated and severe bouts of vomiting, which ‘only occurs in daily long-term users of marijuana,’ according to Cedars-Sinai.

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Krumholtz said he experienced the side effect of ‘hyper-nausea.’

‘I wouldn’t wish it on my worst enemy. I almost died a couple of times,’ he said, adding that he was ‘serious.’

‘I have unpaid emergency room bills up the wazoo. It’s really bad, It’s really dangerous. It’s as serious as a heart attack. It’s horrifying for those that suffer from it.’

He said he thinks ‘no one talks about’ the dangers of weed ‘because it’s the friendly drug, it’s the drug that doesn’t kill you.’

But, he very solemnly added, ‘It’s a very addictive drug … and now that it’s super strong, it’s really addictive.’

Ideally, Krumholtz would like the public to be more aware of the sometimes fatal CHS. 

The Numb3rs star, 46, started using marijuana again after ‘a long break’ and soon became ‘a daily smoker.’ Seen here in 2025

Krumholtz played mathematical genius and college professor Charlie Eppes for six seasons on Numb3rs

Krumholtz also appeared alongside Julia Stiles, Heath Ledger and Joseph Gordon-Leviitt in 10 Things I Hate About You

Krumholtz no longer smokes pot as a result of his experiences with CHS.

‘I would love to see every legal cannabis store be required to have a pamphlet,’ he said. 

‘An optional pamphlet that says, “Hey, if you start feeling nauseous, stop because there is nothing that works except stopping.”‘

Last fall, the 10 Things I Hate About You actor told The New York Times that he’d spend 10 hours a day in H๏τ baths in an attempt to relieve the symptoms of CHS. 

‘I had numbness in my extremities, pain in my chest and my blood pressure skyrocketed,’ he said.

He believes weed would have eventually killed him if his dream role in Oppenheimer hadn’t come along.

The role in the Oscar winning film inspired him to quit smoking weed for good. 

Now Krumholtz is waiting for his next big role and is trying not to lose hope as ‘no one’ is ‘banging on the door.’

Seen on the poster for the film You Stupid Man

‘The hardest part of being in the film that won everything and made $1 billion is that you go into this place of expectation,’ he told The Hollywood Reporter.

‘It’s righteous expectation, but the problem is when it doesn’t pan out or it isn’t panning out, you start to really lose your sнιт and fall into resentment.’

Krumholtz added: ‘So I can’t let that happen because, ultimately, it hurts me and it hurts my acting and it hurts my family.   

‘So I am trying to be as patient as possible, but there’s no one banging at the door, currently.”