The owner of a canned oxygen business says her product can help infected people fight coronavirus, but a medical professor has called the claims "risky" and says oxygen should only be used in "extreme circumstances".
Auckland business Oxygen Please started selling canned "recreational" oxygen in 2017.
The cans contain "95 per cent pure, enriched oxygen" which can be inhaled through a mouthpiece. Information on the company's website said people used the oxygen to provide an "invigorating boost".
It claims the oxygen may help improve energy, stress levels, mental clarity, and may help combat altitude problems, among other things.
But an online advert spotted by a concerned citizen on Facebook showed Oxygen Please was also claiming the product would "help fight Covid-19", and that it was "perfect for the medically frail and health compromised".
But a medical professional said the situation was the opposite, and that oxygen should only be used in "extreme circumstances".
"Oxygen in the wrong circumstances can actually damage the lungs and make for a really unfortunate future," said director of the Malaghan Institute of Medical Research Professor Graham Le Gros.
Oxygen Please owner Leslie Crawford said she has removed the ad, but in comments to the Herald stood by her claims the oxygen was helpful in fighting the virus.
She said this was because Covid-19 was a respiratory illness and it was helpful to the lungs to have more oxygen.
Le Gros said this was not the case and if oxygen was needed, it should be administered by professionals along with other treatments.
Crawford said her elderly mother used oxygen after contracting coronavirus, and found it an "immense relief".
She said criticism of her product came from "trolls" and said there were other things to be focusing on in the current crisis rather than "going around getting little people like me".
"I have changed the ad because we of course do not want to be seen as misleading people, and if that was how it was interpreted it should be changed."
When asked what medical basis she had for the claim the product helped fight the virus, she pointed to her mother's experience with it.
Crawford said she did not need a doctor to tell her it was beneficial, because her mother had already found it useful.
"What other evidence do I need?"
She said she was not in the business to make a profit off the virus, and actually sent out free oxygen cans to people who couldn't afford them.
Le Gros said it was a "scientific fact" that oxygen use could be dangerous, including inhaling 95 per cent oxygen.
Crawford said her product was not "medical grade oxygen".
"This is 95 per cent recreational oxygen. You would need to breathe eight continuous hours of what we sell and that would cost you a small fortune."
Le Gros said Oxygen Please's claims were "very risky".
"People who need oxygen when they're in serious strife with Covid-19 need specialist medical care," he said.
People should not be using oxygen for medical reasons at home, he said, adding it was "unlikely to have any benefit". He also said there was no medical evidence to show there were health benefits to inhaling concentrated oxygen.
He wanted to warn the public to "be very careful about people making claims off the back of Covid-19 issues", and to take medical advice only from their GP and official Ministry of Health information.
A Ministry spokesman said there were now "many companies touting their products as ways of avoiding or treating Covid-19".
"This is unacceptable behaviour and if it occurs in circumstances where it is illegal under the Medicines Act, Medsafe will take action.
"In some cases products are being marketed online from overseas and are beyond the reach of our laws so it is very important for consumers to remain vigilant and sceptical in regard to claims being made."
He said there is currently no specific treatment for the virus, but medical care can manage most symptoms.