Update August 2026. Calocurb is promoted as a natural GLP-1 supplement that can reduce hunger, control cravings and help people lose weight without injections or a prescription. Unlike many weight-loss supplements, its main ingredient has been tested in four published human studies, including a six-month weight-loss trial. However, the results are not quite as simple as the advertising makes them sound, and all four studies have connections to the organization that developed the ingredient. Disclosure: I did not receive compensation from Calocurb for this review. I did not purchase it or use it. This unbiased Calocurb review is based on the clinical trials and what could be discovered from the company website.
Quick Answer: Does Calocurb Work?
Calocurb may help some people eat less and lose a modest amount of weight. In a six-month study, people taking 500 mg of its bitter hops extract lost an average of 8.3 pounds, compared with 0.9 pounds in the placebo group. Both groups also received monthly diet and exercise advice.
Calocurb may increase the body’s natural release of GLP-1 and other appetite hormones, but it is not a natural version of Ozempic or Wegovy. All four published human studies came from the research group that helped develop the ingredient.
What Is Calocurb?
Calocurb is an appetite-control supplement. Its primary ingredient is Amarasate, a patented extract made from New Zealand hops.
Hops are best known for giving beer its bitter flavor. Calocurb does not contain alcohol.
The supplement uses delayed-release capsules designed to pass through the stomach and release the hops extract farther down the digestive tract.
The current label lists approximately 125 mg of Amarasate per capsule.
In two capsules, there are
- 250 mg of Amarasate New Zealand hops flower extract
Other ingredients are
- Canola oil
- Rosemary leaf extract
- Delayed-release vegetable capsule (hypromellose)
The rosemary extract appears to be included mainly to help protect the hops extract from oxidation. It is not the ingredient investigated for appetite control in the Calocurb clinical studies.
What Is Amarasate?
Amarasate is a standardized extract made from hops grown in New Zealand. Researchers developed it while studying how bitter plant compounds interact with receptors in the digestive tract.
The extract is delivered in delayed-release capsules so it reaches the small intestine. There, it may stimulate hormones involved in hunger and fullness, including GLP-1, CCK and PYY.
Amarasate is the name of the patented ingredient. Calocurb is the dietary supplement that contains it.
The technology was developed by Plant & Food Research, which is now part of the New Zealand Institute for Bioeconomy Science. The institute licensed the ingredient for commercial use, and it is now sold internationally in Calocurb.
How Is Calocurb Supposed to Work?
The digestive tract contains receptors that can detect bitter compounds.
When Amarasate reaches the small intestine, it may activate these bitter receptors and stimulate the release of several digestive hormones.
These include:
- GLP-1: Glucagon-like peptide-1
- CCK: Cholecystokinin
- PYY: Peptide YY
These hormones help communicate that food has reached the digestive system. They can influence appetite, fullness, digestion, and how much a person eats.
A small human study found that bitter hops extract increased several of these hormones and reduced the number of calories eaten during a test lunch and snack.
However, the participants did not report feeling less hungry
A supplement can change hormone levels or reduce food intake during one laboratory visit without producing long-term weight loss.
Is Calocurb Really a Natural GLP-1?
Calling Calocurb a “natural GLP-1” is mostly marketing. It may increase the body’s natural release of GLP-1, but it does not work like Ozempic, Wegovy or other GLP-1 medications.
Calocurb does not work like a GLP-1 receptor agonist medication
The supplement attempts to stimulate a temporary release of the body’s own GLP-1 and other digestive hormones by activating bitter receptors in the intestine.
Prescription GLP-1 drugs are designed to activate GLP-1 receptors for a longer period.
Most importantly, no published study has directly compared Calocurb with a prescription GLP-1 medication.
Who Developed Amarasate?
Amarasate was developed by scientists working for New Zealand’s Plant & Food Research.
Plant & Food Research was a government-owned Crown Research Institute. In July 2025, it became part of a larger government-owned research organization called the New Zealand Institute for Bioeconomy Science, also known as the Bioeconomy Science Institute, or BSI.
The institute brought together four former Crown Research Institutes:
- Plant & Food Research
- AgResearch
- Scion
- Manaaki Whenua–Landcare Research
The Bioeconomy Science Institute is government-owned and overseen by an independent board. Its work includes food science, agriculture, forestry, biotechnology and commercialization of research discoveries.
To be fair, government ownership should not be interpreted as government endorsement of Calocurb.
What Is the Bioeconomy Science Institute’s Relationship With Calocurb?
The relationship is more than simply performing research for an unrelated supplement company.
Plant & Food Research created Amarasate and later licensed it to Calocurb, which markets and sells the ingredient in its Calocurb supplement.
Published disclosures have also stated that the institute holds a minor shareholding in Calocurb. This means the institute may benefit financially if Amarasate and Calocurb are commercially successful.
However, this does not prove the results of clinical trials are invalid. Commercial relationships are common when publicly funded research institutes develop something that is later sold.
Calocurb Human Clinical Study Summary
| Year | Participants | Dose | Study Length | Main Finding | Funding & Relationship |
| 2019 | 30 healthy-weight men | 200 mg or 500 mg | Three separate 24-hour fasts | Both doses reduced some hunger ratings during fasting | Plant & Food Research conducted the study and had a licensing agreement with Calocurb |
| 2022 | 20 healthy-weight men | 500 mg | One day per treatment | The bitter hops extract reduced calorie intake during a test lunch and snack by about 17% to 18%; participants did not report feeling less hungry | Conducted by Plant & Food Research employees with New Zealand government funding; Plant & Food Research had a royalty agreement involving Amarasate sales |
| 2024 | 30 healthy-weight women | 250 mg or 500 mg | Three separate 24-hour fasts | The 500 mg dose reduced food intake after fasting by 14.3%; the 250 mg reduction was not statistically significant | Funded by Calocurb; Plant & Food Research licensed the extract to Calocurb and held a minor shareholding in the company |
| 2026 | 150 overweight/obese adults. 128 completed the study | Up to 500 mg daily | 24 weeks | Average weight loss was about 8.3 pounds with bitter hops extract versus 0.9 pounds with placebo | Jointly funded by Calocurb and the Bioeconomy Science Institute; the institute licensed the extract to Calocurb and held a minor shareholding |
Here is a closer look at the studies.
2019 Calocurb Fasting Study
In this study, researchers recruited 30 healthy men in their 20s who were not overweight.
Each man performed three 24-hour fasts. Here's what that looked like
- placebo capsules
- 200 mg of Amarasate
- 500 mg of Amarasate
Results:
- Compared with the placebo, both doses significantly reduced hunger during the final hours of the fast.
- The 500 mg dose also significantly increased fullness during the eight-hour observation period
- Neither dose significantly improved satisfaction or reduced thoughts about food.
- Three men reported loose stools after the 500 mg dose, while one reported loose stools after the 200 mg dose.
Key Takeaways
This was not a weight loss study. Weight loss was not measured.
The study showed that Amarasate reduced hunger and, at the 500 mg dose, increased fullness in healthy men during the final eight hours of a 24-hour water-only fast.
2022 Calocurb Study: Did It Reduce Calorie Intake?
Researchers enrolled 20 healthy-weight men in their 20s. They were not overweight.
On three separate days, they received:
- Placebo capsules
- 500 mg of Amarasate in quick-release capsules designed to release in the stomach
- 500 mg of Amarasate in delayed-release capsules designed to release in the small intestine
Results
Compared with the placebo, the men ate approximately:
- 218 fewer calories after the quick-release treatment
- 226 fewer calories after the delayed-release treatment
This amounted to about a 17% reduction in calories eaten at lunch and during the afternoon snack.
Both versions of the bitter hops extract increased the overall release of GLP-1, CCK and PYY. These hormones are involved in appetite, digestion and fullness.
Key Takeaways
500 mg dose of Amarasate reduced the combined calories eaten by about 17%. The reduction came mainly from eating less during the afternoon snack.
This was not a weight loss study. Weight loss was not measured.
The study did not show that the men felt less hungry
2024 Calocurb Study in Women: Hunger, Cravings and Food Intake
Researchers recruited 30 healthy, normal-weight women. Their average age was 21. They were not overweight.
Each woman completed three separate 24-hour water-only fasts. During the final eight hours of each fast, they received:
- Placebo capsules
- 125 mg of Amarasate twice daily, for a total of 250 mg
- 250 mg twice daily, for a total of 500 mg
At the end of each fast, the women were given a rice-based meal and told to eat until comfortably full.
Results
- During the final eight hours of the fast, women taking either dose of Amarasate reported lower hunger ratings than when they took the placebo.
- They were still hungry, but their hunger did not rise as much.
- The women ate 14.3% fewer calories after taking 500 mg of Amarasate.
- They ate 8.1% fewer calories after taking 250 mg.
- The 500 mg dose also produced a significant overall improvement in fullness and satisfaction.
- The supplement did not appear to reduce cravings for sugary, spicy or fatty foods.
Key Takeaways
This was not a weight loss study.
The women were young and did not need to lose weight
The study lasted only one day per treatment and was combined with fasting for 24 hours
The 500 mg dose appears to work better than 250 mg
2026 Calocurb Study: How Much Weight Did People Lose?
This was the first Calocurb study to measure weight loss over several months.
Researchers recruited 150 men and women who were overweight or obese. Their average age was 35. About 75% were women.
The people were divided into two groups:
- 75 received Calocurb
- 75 received placebo capsules
The study was randomized and double-blind. Neither the participants nor the researchers working with them knew who was receiving Calocurb.
Participants gradually increased their dosage by 125 mg per week until they reached 500 mg per day. This was divided into four capsules. Half the daily dose was taken at least one hour before each of the two largest meals of the day.
Both groups attended weekly weight loss advice from a dietitian
Results
- People taking Calocurb reported eating an average of 130-180 fewer calories daily compared to placebo takers.
- Those taking Calocurb lost an average of about 4.3% of their starting weight (about 8.3 lbs or 3.8 kg)
- Not everyone taking Calocurb lost weight
- Calocurb promoted the loss of about 9.9 pounds of body fat (4.5 kg)
- The supplement appeared to reduce hunger but not improve feelings of fullness, thoughts about food or satisfaction
- Calocurb did not reduce cravings for sugary foods.
Key Takeaways
People taking 500 mg of Calocurb lost about 8.3 pounds after 6 months compared to about 1 pound in placebo takers.
Weight loss probably due to people eating fewer calories
Levels of GLP-1 and other hunger hormones were not measured
Of the 150 people who started the study, 128 completed (85% completed the study)
The people were basically young and healthy
What Does “9 Times More Weight Loss” Mean?
Calocurb promotes “9 times more weight loss than willpower alone.”
This claim comes from the 2026 study:
- Bitter hops extract group lost approximately 8.3 pounds
- Placebo group lost approximately 0.9 pounds
Dividing 8.3 by 0.9 produces a number slightly greater than nine.
While the math is reasonable, the way it is presented can still be misleading.
The number sounds dramatic because the placebo group lost less than one pound.
The actual difference between the groups was about: 8.3 pounds minus 0.9 pounds = 7.4 pounds
Remember, this occurred over the course of 6 months.
Also, this didn't compare Calocurb to willpower alone because the placebo takers also
- Attended weight loss classes conducted by a dietitian
- were advised to eat more protein and eat better overall
- Encouraged to exercise
Does Calocurb Reduce Hunger by 30%?
Calocurb promotes claims involving approximately:
- 30% less hunger
- 40% fewer cravings
- 18% less food intake
These numbers come from different studies, involving different groups and testing conditions.
The hunger and craving numbers were largely based on subjective rating scales during 24-hour water-only fasts.
This does not mean every person taking Calocurb will feel exactly 30% less hungry during normal daily life.
The 18% food-intake claim comes from the 2022 study in which healthy-weight men consumed less food during one lunch and snack.
Does Calocurb Burn Fat?
There is no convincing evidence that Calocurb directly increases fat burning.
The most likely explanation for the weight loss is that the bitter hops extract helps some people consume fewer calories.
How Do You Take Calocurb?
The company recommends gradually increasing the dosage.
- Day 1 and 2: One capsule daily
- Days 3 and 4: One capsule twice daily
- Day 5 and after: Two capsules, 2x a day
Take no more than 4 capsules a day
The capsules are generally taken on a relatively empty stomach about one hour before a meal.
Four capsules supply approximately 500 mg of Amarasate. This matches the daily dose used in the six-month weight-loss study.
The gradual increase is sensible because diarrhea and nausea occurred more often at max dose.
Does One Bottle Last One Month?
A bottle contains 90 capsules.
At four capsules per day:
90 capsules ÷ 4 capsules daily = 22.5 days
One bottle therefore does not last a full 30 days at the dose used in the six-month study.
At two capsules per day, a bottle lasts 45 days. However, that provides only 250 mg per day.
The Calocurb website has described 90 capsules as approximately a one-month supply. That may reflect the fact that some people use fewer than four capsules daily.
People comparing the price with the clinical research should calculate the cost based on four capsules per day.
How Much Does Calocurb Cost?
At the time this review was updated, one bottle containing 90 capsules cost approximately $89.99 before discounts.
At the full 500 mg study dose:
- One bottle lasts 22.5 days.
- Thirty days costs approximately $120.
- Six months costs approximately $720.
- One year costs approximately $1,460.
Subscription and multi-bottle discounts may reduce the price.
Calocurb Side Effects
The most common side effects reported in the human studies included:
- Diarrhea
- Loose stools
- Nausea
- Abdominal discomfort
- Bloating
- Heartburn
The six-month trial suggests that gradual dosage increases are appropriate. Even with gradual increases, approximately 10% of those taking the bitter hops extract needed to reduce the dose because of digestive symptoms.
Anyone who develops persistent diarrhea, vomiting or severe abdominal pain should stop taking the product and contact a healthcare provider.
Calocurb and Allergic Reactions
In 2018, New Zealand’s Medsafe published a safety communication after receiving a report of a serious allergic reaction associated with Calocurb.
The person reportedly developed:
- Abdominal discomfort
- Red and itchy hands
- Worsening symptoms
- Loss of consciousness
Hospital treatment was required, and anaphylaxis was diagnosed.
At the time, the product contained Amarasate, rosemary leaf extract and canola oil. Medsafe could not determine which ingredient may have caused the reaction.
This was one spontaneous report. However, the report is serious enough that customers should know about it.
Who Should Not Take Calocurb?
The manufacturer says Calocurb has not been tested in:
- People younger than 18
- Pregnant women
- Breastfeeding women
The company also advises against its use by people with gastrointestinal inflammation or inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis.
Calocurb is not been proven effective for people with type 1 diabetes or type 2 diabetes.
Can You Take Calocurb With Ozempic, Wegovy or Zepbound?
No published clinical trial has tested Calocurb in combination with a GLP-1 or GIP/GLP-1 medication.
The six-month Calocurb study excluded people taking GLP-1 drugs and other weight-loss medications.
The company has suggested that Calocurb might:
- Complement injectable medications
- Help people use a lower drug dosage
- Help maintain weight after stopping a GLP-1 medication
Those possible uses have not been proven in the published Calocurb studies.
No one should reduce or stop a prescription medication based on a supplement company’s claim.
Is Calocurb FDA Approved?
No. The FDA does not approve dietary supplements for effectiveness before they are sold to customers.
Calocurb being legally sold as a supplement does not mean the FDA has reviewed or confirmed its weight-loss claims.
What I Like About Calocurb
- Several published human studies
- Has a 6-month-long randomized trial
- Active dose is disclosed
- No proprietary blends
- Study funding/disclosures are published
What I Don't Like About Calocurb
- Company claims about “Natural GLP-1”
- Claims about preserving muscle (it's marketing spin)
- Several studies involve 24-hour water fasts (most people won't do that)
- No independent replication of studies
- A bottle might not last a month
Calocurb Review: My Thoughts
Calocurb is one of the more interesting appetite-control supplements I have reviewed.
Its main ingredient has been tested in four published human studies, including a six-month randomized trial. That is more evidence than exists for many supplements marketed as natural GLP-1 products.
The best study found that people taking 500 mg of bitter hops extract daily lost an average of approximately 8.3 pounds over six months. Based on the existing evidence, Calocurb may help some people eat less and lose a modest amount of weight.
That said, its marketing sometimes goes beyond what the studies firmly establish as fact. This supplement is expensive, so do the math first to see if the price fits your budget.
Calocurb Frequently Asked Questions
How much weight can you lose with Calocurb?
In one six-month study, participants taking 500 mg of bitter hops extract daily lost an average of approximately 8.3 pounds. Those taking a placebo lost about 0.9 pounds. Both groups received monthly lifestyle instruction.
How long does Calocurb take to work?
The short-term studies detected changes in appetite hormones, food intake, or hunger ratings within several hours. However, it may take 6 months to see a noticeable difference.
Does Calocurb increase GLP-1?
A small short-term study found that bitter hops extract increased natural GLP-1 secretion. Calocurb does not contain GLP-1, and the increase should not be considered equivalent to taking a GLP-1 medication.
Does Calocurb reduce cravings?
A fasting study in healthy women found improvements in some food-craving ratings. The study lasted only 24 hours, so it does not establish long-term craving control.
Does Calocurb reduce food noise?
Calocurb may reduce certain hunger or craving sensations in some people. No study has shown that it treats “food noise” as a diagnosed condition.
Does Calocurb burn fat?
Calocurb has not been shown to directly increase fat burning. Its likely benefit comes from helping some people consume fewer calories.
Does Calocurb preserve muscle?
In the six-month study, neither the Calocurb group nor the placebo group lost skeletal muscle. This means the weight loss was not accompanied by detectable muscle loss. It does not prove Calocurb directly protects muscle.
Does Calocurb contain caffeine?
Caffeine is not listed among the current ingredients. It appears to be stimulant-free.
Is Calocurb safe?
Most reported side effects were digestive, including diarrhea, nausea and abdominal discomfort.
A serious allergic reaction was also reported to New Zealand health authorities in 2018. The long-term safety database remains relatively small.
Can Calocurb replace Ozempic?
No. Calocurb is a dietary supplement. It is not a GLP-1 medication and has not produced medication-level weight loss in clinical trials.
Can Calocurb be taken with a GLP-1 medication?
No published study has tested this combination. Speak with the healthcare professional prescribing the medication before adding Calocurb or another appetite suppressant.
Does Calocurb work without diet and exercise?
The six-month study combined the hops extract with monthly diet and exercise instruction.
The study does not tell us how much weight people would lose if they made no lifestyle changes.
Are the Calocurb studies independent?
Not completely.
All four published human studies were conducted by the same research group that developed the ingredient. The research institute licenses the ingredient to Calocurb, holds a minor shareholding and helped fund the newest trial. The studies remain useful, but independent replication would strengthen the evidence.
Did Calocurb reduce your hunger or help you lose weight? Share your experience in the comments below.
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