Josh Hartnett has revealed he was left unable to walk for around 10 days after a bout of food poisoning caused his muscles to seize up while he was filming Verity, the new Colleen Hoover adaptation.

The 48-year-old actor, who stars alongside Anne Hathaway and Dakota Johnson in the psychological erotic thriller, recalled the episode on SiriusXM's Front Row podcast on 1 October. The film, directed by Michael Showalter, was released in cinemas the following day.

'It was food poisoning, but it was a terrible food poisoning,' Hartnett said. 'What it was is that I couldn't walk because my muscles had all seized up.'

He said the worst of the illness lasted 'really only about 10 days' and overlapped with 'only a few days of shooting'. Entertainment website reported that the cramps stemmed from vomiting and dehydration.

Medical guidance explains how such cramps can arise. In their website, Cleveland Clinic explained that frequent vomiting and diarrhoea can drain the body of large amounts of water and electrolytes, adding that severe dehydration is the most common complication of food poisoning.

The clinic lists muscle cramps among the symptoms of dehydration and says they may be due to a shortage of electrolytes, such as sodium and potassium. The guidance is general and does not describe Hartnett's own case.

The account of the illness comes from Hartnett himself, and the reported comments do not say what caused the food poisoning.

Director Lifts Lid on Hartnett's On-Set Health Battle

Showalter, who has traditionally worked in comedy and whose previous films include The Idea of You (2024), described how demanding the production was for Hartnett.

'For most of the movie, when Josh isn't on camera, he's lying down being tended to,' the director said. 'Josh was battling some very, very, very serious thing.'

Hartnett, whose earlier credits include Pearl Harbor (2001) and Oppenheimer (2023), plays Jeremy Crawford. Hathaway, who is also a producer on the film, plays his wife, Verity Crawford, while Johnson plays Lowen Ashleigh.

Based on Hoover's bestselling novel, the story follows Lowen, a struggling writer hired to finish the book series of Verity, a successful author who is unable to write. The film is the latest screen adaptation of Hoover's work, following It Ends With Us (2024) and Regretting You (2025).

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Cast Recall Surprising Mood on 'Verity' Set

Despite the illness, Hartnett has described the shoot as an enjoyable one. He said: 'I didn't have anything to come down from at the end of the day.'

He credited Showalter's comedy background, saying the director had 'a really good sense of how to make' the gothic, horror-tinged story work, but that this 'didn't translate to the set experience'.

Hartnett said the cast's chemistry grew out of friendship and 'enjoying each other's company'. 'In the middle of some of these darker scenes, there were some laughing fits that just didn't stop,' he said.

Hathaway told E! News she arrived on set 'really, really, really pumped every day' to work with Hartnett and Johnson, although she did not know either of them well beforehand.

'It's really cool to work with actors that have such amazing filmographies,' she said. She added that she 'knew what they were capable of as actors' and was keen to see them go to 'a place that you've never even gone before'. In her view, knowing the script and her co-stars' potential helped the cast bond before cameras began rolling.

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