Pints to pills: how New Zealand hops can fight obesity
Calocurb, a New Zealand dietary supplement made from hop flowers, has delivered impressive clinical study results, according to some weight-loss experts
Serena SolomonLifestyle journalist
28 July 2026
9 min read
Serena SolomonLifestyle journalist
28 July 2026
9 min read
Caption:Colin Oldham, a third-generation hop farmer in Motueka, with his two sons Tom (middle) and Hayden (left).Photo credit:NZ Hops
Colin Oldham, 63, is acutely aware that the high-carb content of beer can contribute to weight gain. After all, he farms 60 acres of hop vines in Motueka. Hops are the key ingredient in beer
“I had put on some weight – the middle-age spread – and decided to do something about it.”
What’s ironic is he started taking Calocurb, an appetite-suppressing dietary supplement made from the hop flowers he grows. Since he started taking the pills daily a year ago, he has lost seven kilograms
“When you grow a product and then, as a passionate third-generation hop grower, get in after work and have a cold beer made from your hops, and then also take a pill to keep your weight under control [made] with the same product – I mean, life can’t get better.”
The folks at Calocurb might be singing a similar tune. The supplement, born of a true New Zealand discovery in 2010, recently released the results of a clinical study that shows promising results but with some limitations, according to two New Zealand weight-loss experts. While labelling Calocurb as something of a natural GLP-1 weight loss wonder is a tall exaggeration – the GLP-1 Wegovy achieves an average of 13 percent body weight loss compared to Calocurb’s 4.3 percent– the study hints at a role the supplement could play in the fight against the global obesity epidemic and the middle-aged spread.
How does Calocurb works?
GLP-1 weight loss medications have become a key weapon in the fight against obesity in recent years. Wegovy and Mounjaro, both weekly injectables, are the only two available in New Zealand from this new era of GLP-1s. The drugs are privately funded and cost between $400 and $800 a month
Drugs like Wegovy mimic the gut hormone known as GLP-1 to promote a feeling of fullness while slowing down digestion. Calocurb uses our evolutionary response to bitterness, stimulating the release of those fullness hormones to reduce food cravings and hunger. Less food, fewer calories equals weight loss, similar to Wegovy but with reduced results. The price tag is lower, but it will still cost you around $110 a month if taken as directed
Calocurb was launched in 2018 after New Zealand’s Plant and Food Researchscreened 900 plant extracts to see what might suppress appetite
What does the study say?
The randomised placebo-controlled clinical study, the gold standard of studies, followed 150 overweight and obese adults for six months. Those who took Calocurb – and not the placebo – lost an average of 3.8 kg, which was all fat mass and not lean muscle mass. The speed at which Wegovy users lose weight has caused issues with lean muscle mass loss – between 20 and 40 per cent of total body mass loss. This can negatively impact strength, metabolism and bone density
Calocurb spent $2 million to conduct the study, which sets it apart from similar supplements that often lack the science to back up their marketing claims, says Calocurb CEO Sarah Kennedy
What do weight loss experts say?
Dr Maria Casale, a dietitian at Massey University, called the study’s results “very promising” but added it was one significant study and more research needed to be done to determine Calocurb’s true effectiveness. The company had previously completed three much smaller studies that also had positive results
Muscle mass may have been preserved simply because the weight loss was lower and slower compared to something like Wegovy, she says. Casale disputed the company’s claim that this latest study demonstrated “sustained weight loss over time”
“They’ve done 24 weeks. Let’s see those people in another two years and see where they’re at, who are in this study, and then we would know. And even then, really up to five years, you should be following people.”
Peter Shepherd, an obesity and diabetes professor at the University of Auckland, has followed the company’s progress for several years. He tried it for a week and found it reduced his appetite and “food noise,” the intrusive thoughts about food that GLP-1 users often say are eliminated on the medication
“That’s a proper clinical trial under proper conditions, and it’s achieving real-world weight loss.”
The fact that some US-based companies are trying to mimic the same concept demonstrates Calocurb is onto something, he says
How could Calocurb be used?
Those who are using Wegovy likely have a BMI over 30 and are considered obese. Weight loss can be a matter of life or death given the potential for obesity to lead towards comorbidities like diabetes and heart disease. Calocurb, based on the results of this new study, likely won’t move the dial much for those patients, Casale says
“I think my concern is this will feed into a lot of body dissatisfaction, a lot of body image [issues], the pressure we have to look a certain way, and people will see this as a cheap alternative.”
Kennedy says Calocurb is finding success in the US, where some doctors are using it for patients who stop using medications like Wegovy due to severe side effects. About 15 percent of participants in clinical trials pulled out because of side effects such as nausea and vomiting. One patient in the Calocurb study pulled out due to side effects from taking the supplement
Other doctors are using Calocurb along with weight loss medications to reduce the dose and thus the cost of drugs like Wegovy, says Kennedy. There is also a role for Calocurb as a stepping stone if patients want to come off a GLP-1 medication. Drug makers often describe the drug class as “forever medications” with numerous studies indicating that those stopping a GLP-1 like Wegovy regain much, if not all, of their lost weight because the food noise and appetite can return with a vengeance. Calocurb could temper that response, says Kennedy.
However, two of the weight-loss doctors in New Zealand interviewed previously for GLP-1 stories had heard very little about Calocurb and are yet to recommend it to patients. Kennedy says the reason for that is likely because Calocurb has focused its marketing on the $97 billion US obesity and diabetes market, where more than 10 percent of the population report using a GLP-1 medication
What does this mean for hop growers?
Calocurb sold 250,000 units in 2025, a growth of 300 percent, says Kennedy
Back on the farm, new plants of the unique variety of hop used in Calocurb are going into the ground to meet growing demand, says Blair Stewart, the CEO of NZ Hops, a cooperative of 24 hop farms in the Motueka area. About five percent of Oldham’s land, the hop farmer who is now seven kilograms lighter, is Calocurb’s hop variety
“By far and away, our biggest demand is for beer,” says Stewart
“… but the neat thing about Calocurb is now we have an additional demand or opportunity to grow for a completely new sector, and that’s exciting for us.”
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28 July 2026
