Calocurb® and Amarasate®: What the Research Shows About Appetite, Cravings and Weight Loss

What Is Calocurb® with Amarasate®?

Calocurb® is a plant-based appetite-support supplement containing Amarasate®, a proprietary extract made from hops grown in New Zealand.

Hops are better known for beer, but their bitter compounds have another biological property. The gastrointestinal tract contains bitter taste receptors, and activating them can influence some of the signaling involved in digestion, appetite, and satiety.

Amarasate® was developed through research originating at New Zealand's Plant & Food Research. The extract is concentrated and placed in a delayed-release capsule so that the bitter compounds can reach the gastrointestinal tract without requiring anyone to actually taste them.

That delivery system is a meaningful part of the product. The goal is not simply to swallow hops. It is to expose gastrointestinal receptors to a defined bitter hop extract at a useful point in digestion.

The Gut Has Bitter Taste Receptors Too

Taste receptors are not confined to the tongue.

Bitter taste receptors are also expressed within the gastrointestinal tract, including on enteroendocrine cells. These cells act as chemical sensors. When nutrients and other compounds arrive in the intestine, they help coordinate the release of hormones involved in digestion, glucose regulation, gastric function, and appetite.

Studies of the Amarasate® hop extract have found changes in several of these hormones, including:

• GLP-1, which participates in satiety, insulin signaling, and regulation of food intake
• CCK, which contributes to meal-related fullness and digestive signaling
• PYY, another gut-derived signal associated with satiety and food intake

This pathway is sometimes described as a "bitter brake": bitter compounds reaching the gastrointestinal tract appear capable of triggering signals that reduce subsequent energy intake.

The biology is more interesting than the marketing shorthand. Calocurb® does not simply "switch on GLP-1." Several gut hormones, neural pathways, meal signals, and digestive responses are involved.

What Have the Human Trials Actually Found?

The early Calocurb research was small, but it produced several useful findings.

A randomized crossover study published in 2019 examined Amarasate® during a 24-hour water-only fast in 30 men. Participants receiving either of two doses experienced more than a 10% reduction in hunger during the later part of the fast compared with placebo.

A 2022 randomized crossover trial took a closer look at the mechanism. Nineteen healthy-weight men received placebo or 500 mg of the bitter hop extract delivered either to the stomach or farther into the gastrointestinal tract.

Food intake at a subsequent lunch and snack was roughly 17% lower after the hop extract than after placebo. Blood testing also showed increases in post-meal GLP-1, CCK, and PYY.

Interestingly, the men did not report a significant subjective reduction in appetite despite eating less. Some also experienced gastrointestinal symptoms including nausea, bloating, and abdominal discomfort.

That is a useful reminder that a statistically significant biological effect is not necessarily the same thing as dramatically "feeling" an appetite suppressant working.

A 2024 randomized crossover study extended the fasting research to 30 healthy adult women. Both tested doses of Amarasate® reduced appetite and food cravings during a 24-hour fast compared with placebo. A small number of participants reported loose stools or heartburn.

The 2026 Study Is the More Interesting One

Short feeding studies can tell us whether a compound changes appetite or food intake for a few hours. They cannot tell us much about weight loss over months.

A study published in 2026 began to address that question.

Researchers enrolled 150 men and women with overweight or obesity in a 24-week randomized, double-blind trial. Everyone participated in a lifestyle program with monthly diet and exercise guidance. Participants were assigned either placebo or 500 mg per day of the bitter hop extract, divided before the two major meals of the day.

One hundred twenty-eight participants completed the study.

At 24 weeks, the hop-extract group had lost 4.3% of baseline body weight and approximately 4.5 kilograms of fat mass. Compared with placebo, the study reported a 3.8% greater reduction in body weight and a 3.9-kilogram greater reduction in fat mass.

The researchers also used bioelectrical impedance analysis to follow body composition. They did not observe a loss of estimated skeletal muscle mass in either group.

That finding is encouraging, particularly because preserving muscle during weight loss is central to healthy aging. It should still be interpreted appropriately. Bioimpedance is not the same as a direct measurement of muscle tissue, and one 24-week study does not establish that Amarasate® protects muscle independently of nutrition and exercise.

The trial also had a commercial connection worth knowing about. The New Zealand public research organization involved in the work licenses the bitter hop extract to Calocurb Ltd and holds a minority interest in the company.

None of that invalidates the findings. It belongs in the interpretation.

Calocurb® Is Not a Natural Ozempic®

The connection to GLP-1 has made products like Calocurb® particularly marketable. It has also created plenty of room for exaggeration.

Prescription GLP-1 receptor agonists such as semaglutide are medications specifically engineered to activate the GLP-1 receptor for prolonged periods. Tirzepatide acts on both GIP and GLP-1 receptors. Their pharmacology, clinical effects, adverse-effect profiles, and weight-loss results are in a completely different category from a dietary supplement.

Amarasate® appears to stimulate the body's own gastrointestinal signaling and increase endogenous GLP-1 along with CCK and PYY. It does not turn Calocurb® into a botanical version of semaglutide.

For appropriate patients, prescription GLP-1 therapy can be part of a much broader GLP-1 Weight Loss for Longevity™ strategy. Calocurb® occupies a different space.

Someone who does not need or want prescription weight-loss medication may find appetite support useful. Someone already taking semaglutide, tirzepatide, or another appetite-modifying medication should discuss additional appetite supplements with the prescribing clinician rather than stacking them casually.

Calocurb®, Fasting, and Cravings

The fasting studies are particularly relevant because hunger is one of the main reasons fasting protocols fall apart.

There is no prize for making fasting unnecessarily difficult.

If a reasonable fasting window works well for someone's metabolism, schedule, and eating behavior, reducing hunger during the final hours may make adherence easier. The male and female Amarasate® trials suggest that bitter-hop signaling can help in that setting.

Fasting is not automatically superior to every other eating pattern, and it can be a poor choice for some people. A person who fasts aggressively and then overeats at night has not necessarily improved anything.

The same is true of cravings. Persistent evening hunger may reflect inadequate daytime protein, excessive calorie restriction, poor sleep, stress, medication effects, glucose instability, or simply a nutrition plan that is too restrictive to sustain.

An appetite supplement can sometimes reduce the friction. It should not prevent us from asking why the friction is there.

How Is Calocurb® Taken?

Calocurb® is generally taken before a meal or during a fasting window, with timing intended to allow the delayed-release capsule to reach the gastrointestinal tract before food arrives.

The manufacturer currently recommends beginning with a lower dose and increasing gradually as tolerated, generally taking the product on an empty stomach about an hour before a meal. The current maximum is four capsules per day.

Because dosing instructions can change with product formulation and labeling, use the directions on the current bottle rather than relying on an old article or social-media post.

Gastrointestinal symptoms have occurred in clinical studies, including nausea, bloating, abdominal discomfort, loose stools, and heartburn. Starting conservatively makes sense.

People who are pregnant or nursing, have significant gastrointestinal disease, have a history of disordered eating, take glucose-lowering or appetite-modifying medication, or are under medical treatment should discuss use with their healthcare professional first.

Where Calocurb® Fits in Longevity Medicine

Weight loss becomes much more useful when we stop treating pounds as the primary outcome.

The real targets are usually excess fat, visceral fat, insulin resistance, cardiovascular risk, mobility, strength, and metabolic health. At the same time, we want to protect muscle and bone.

This is why someone losing weight at HormoneSynergy® may be followed with Hologic® DEXA and body-composition testing rather than relying entirely on a bathroom scale. Two people can lose ten pounds and have very different changes in fat and lean tissue.

It is also why appetite should be considered alongside metabolic physiology. Our guide to insulin resistance and metabolic health explains why glucose, insulin, visceral fat, muscle, sleep, hormones, activity, and nutrition all belong in the same conversation.

Calocurb® can be one tool inside that framework. For someone whose main obstacle is hunger between meals, difficulty maintaining a fasting window, or portion control, the Amarasate® research gives the product a plausible role.*

It is not the foundation of a weight-loss program. Protein, resistance training, dietary quality, sleep, metabolic evaluation, and an eating pattern that can actually be maintained still matter more.

That is how we think about supplements generally: useful when they solve a particular problem, unnecessary when they do not.

Where to Buy Calocurb®

HormoneSynergy® carries Calocurb® with Amarasate® for patients and customers looking for non-stimulant appetite support as part of a broader nutrition or metabolic-health strategy.*

View Calocurb® with Amarasate® →

Frequently Asked Questions

What is Amarasate®?

Amarasate® is a proprietary bitter extract derived from New Zealand hops. It is the active ingredient used in Calocurb® and has been studied for its effects on gastrointestinal satiety signaling, appetite, food intake, and weight management.

Does Calocurb® increase GLP-1?

Human research with the Amarasate® bitter hop extract has reported increased endogenous GLP-1 along with CCK and PYY following gastrointestinal delivery. Calocurb® is not a GLP-1 receptor agonist medication.

Is Calocurb® the same as semaglutide or tirzepatide?

No. Semaglutide and tirzepatide are prescription medications with substantially different pharmacology and clinical effects. Calocurb® is a dietary supplement intended to support the body's own gut-derived satiety signaling.*

Can Calocurb® help with intermittent fasting?

Small randomized studies in both men and women found that Amarasate® reduced hunger or appetite during a 24-hour fast. Whether it is useful depends on the individual and whether fasting is an appropriate eating strategy in the first place.*

Has Calocurb® been studied for actual weight loss?

Yes. A 2026 randomized, double-blind 24-week study in adults with overweight or obesity found greater body-weight and fat-mass reductions with a bitter hop extract alongside lifestyle counseling than with placebo. The study is encouraging but should be considered one part of a still-developing evidence base.

Does Calocurb® preserve muscle during weight loss?

In the 2026 study, bioelectrical impedance measurements did not show a reduction in estimated skeletal muscle mass. That does not establish Calocurb® as a muscle-preservation treatment. Adequate protein, resistance training, and appropriate body-composition monitoring remain the more important strategies.

Can Calocurb® cause side effects?

Gastrointestinal symptoms reported in clinical studies have included nausea, bloating, abdominal discomfort, loose stools, and heartburn. Tolerance varies by person and dose.

Clinical References

• Bitter hop nutraceutical stimulates fat mass loss while preserving muscle mass in a cohort of individuals with overweight or obesity receiving diet and exercise advice. 2026.
• Walker EG, et al. An extract of hops (Humulus lupulus L.) modulates gut peptide hormone secretion and reduces energy intake in healthy-weight men: a randomized, crossover clinical trial. American Journal of Clinical Nutrition. 2022.
• Gastrointestinal delivery of bitter hop extract reduces appetite and food cravings in healthy adult women undergoing acute fasting. 2024.
• New Zealand Bitter Hops Extract Reduces Hunger During a 24 h Water Only Fast. 2019.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This article is for educational purposes and is not a substitute for individualized medical advice. Speak with your physician or qualified healthcare professional before adding an appetite-support supplement if you are taking prescription weight-loss or diabetes medication, have a medical condition, are pregnant or nursing, or have a history of disordered eating.