"Our advice to consumers would be to spend their money on food, not overpriced supplements."
Aucklander Taryn Crewe said she had been using the patches with a capsule and a shake daily for the past two years and had so much energy she ran a marathon last year.
She was aware of scepticism from nutritionists but said she had done her research and that the results spoke for themselves.
"Yes there is the whole natural route and eating well, but I think it's unrealistic in today's busy life — I leave for work at 7.30am and get home at 7pm.
"It's a long day. Food is not as natural as it used to be and you have to eat so much of it to get the right amount of vitamins."
South Islander Megan Jones said she had "huge amounts of energy" after wearing the patches and was unperturbed by scepticism.
"I'm finding it's not as efficient as it was but it's still great. I kind of took a stab at it after seeing it on Facebook. It really was just to give me energy and it has totally done that," she said.
She no longer drank coffee and was out of bed at 6am, she said.
Auckland University of Technology senior nutrition lecturer Dr Caryn Zinn said the claim people could derive nutrients through a patch was dubious.
"There's not one hint of science that I can see," she said. "My advice would be for people to be very wary ... you don't suddenly get weight loss by taking a pill or putting something through the skin."
Similar products are on the online market, including Vitamin C and Vitamin B patches, and Invigorate consultant dietician Dr Kirsty Fairburn said there had been studies on patches used for skincare.
However, scientific literature databases made no mention of the use of trans-dermal vitamin technology, she said. People worried about their health, weight or energy levels were better off spending the money on seeing a dietician, she said.
A Ministry of Health spokesman said Medsafe was not aware of the product and Medsafe had not assessed it for safety, quality or effectiveness.
Under medicines regulations therapeutic claims could not be made about a medicine unless it has been approved for supply or was otherwise supplied in compliance with the Medicines Act 1981, he said.
Le-Vel's website claims it has amassed nearly half a billion dollars in revenue in 2016 and nearly as many customers.
According to the website, Thrive's premium lifestyle patches start at $90 for a pack of 30 patches, and go up to $128.
Representatives of the company have not responded to approaches for comment.
In 2015 the company was warned by the United Kingdom's Advertising Standards Authority after a complaint was laid about its promotion of a health drink.