Ghrelin Hormone: What It Is, Function & Levels

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Ghrelin is a hormone your body produces and releases. It signals your brain when your stomach is empty and it’s time to eat. Ghrelin levels increase between mealtimes and decrease when your stomach is full. People who have obesity often have low ghrelin levels, while people who greatly limit calories have high ghrelin levels.

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Ghrelin is a hormone your stomach makes. Other parts of your body, such as your brain, small intestine and pancreas, also release small amounts of it.

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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Often known as the “hunger hormone,” ghrelin (pronounced “GREL-in”) has several functions in addition to telling your brain you’re hungry.

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Ghrelin levels increase when your stomach is empty. Your body releases it to let your brain (specifically, your hypothalamus) know when it’s time to eat. Then, when you eat, your ghrelin levels decrease.

Ghrelin has several other key functions. The hormone:

• Promotes storage of body fat
• Makes your pituitary gland release growth hormone
• Makes your digestive system move food from your stomach through your small and large intestines
• Helps control insulin release
• Triggers your pancreas to release glucagon

Ghrelin also plays a role in:

• Protecting your cardiovascular health
• Learning and memory
• Stress
• Mood and anxiety
• Sleep-wake cycle (circadian rhythm)

Scientists are actively studying all the ways ghrelin impacts body functions and health.

Your stomach releases ghrelin when it’s empty or mostly empty. Levels are typically highest right before mealtimes.

Ghrelin levels tend to be lower in people who have obesity compared to people who have more muscle mass. Some researchers think this could mean that people who have obesity are naturally more sensitive to the hormone. They may feel much hungrier with lower levels of ghrelin.

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Certain gastrointestinal diseases are also associated with low ghrelin, including:

• Chronic gastritis
• Functional dyspepsia
• H. Pylori infection
• Irritable bowel syndrome (IBS)

People who have gastric bypass surgery may also have lower levels.

You may have increases in ghrelin levels if you limit how many calories you consume. Ghrelin levels increase after you lose weight from restricting calories. This may explain why it’s difficult to keep losing weight from dieting. It’s known as the weight loss plateau.

High ghrelin may also be associated with conditions like:

• Anorexia nervosa
• Cachexia, a condition that causes your muscles to waste away
• Celiac disease
• Inflammatory bowel disease (IBD)
• Prader-Willi syndrome

Ghrelin levels tend to rise and fall with how much you eat. But other factors can affect the amount of this hormone as well.

The following habits may help keep ghrelin and other hormone levels healthier:

• Avoid fad or yo-yo dieting, where you gain and lose weight frequently.
• Eat foods that contain healthy carbohydrates (like whole grains) and lean proteins (like chicken or fish).
• Limit processed foods, especially foods high in sugar, high-fructose corn syrup and salt.
• Sleep at least seven to eight hours nightly.
• Stay hydrated by drinking plenty of water and eating water-filled foods, like fruits and vegetables.
• Manage your stress responses, as stress may increase ghrelin.

No specific food suppresses ghrelin. In general, eating foods high in healthy carbohydrates and protein may lower your ghrelin levels.

If you have obesity or are having difficulty losing weight, talk to a healthcare provider. Countless factors can play into obesity and weight management. Abnormal ghrelin levels could be one of many factors.

Providers don’t test your ghrelin levels when assessing weight wellness progress. But going over your symptoms and weight loss strategies can help them figure out the best treatment plan for you.

If you have persistent hunger that feels extreme or different from your normal, see a provider. It could be a sign of certain health conditions.

Ghrelin is mainly known for that pang of hunger you feel when you haven’t eaten in a while. But ghrelin is a hormone of many functions. It also signals your body to release other hormones and protects your cardiovascular health. Scientists are still learning about all the ways it affects your body. If you’re having issues with hunger cues or weight management, reach out to a healthcare provider.

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Cleveland Clinic’s health articles are based on evidence-backed information and review by medical professionals to ensure accuracy, reliability and up-to-date clinical standards.

Cleveland Clinic’s health articles are based on evidence-backed information and review by medical professionals to ensure accuracy, reliability and up-to-date clinical standards.

• Cheung CK, Che-Yuen Wu J. Role of Ghrelin in the Pathophysiology of Gastrointestinal Disease (https://pubmed.ncbi.nlm.nih.gov/24073306/). Gut Liver. 2013 Sep;7(5):505-512. Accessed 2/18/2026.
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• Kulkarni SS, Singh O, Zigman JM. The intersection between ghrelin, metabolism and circadian rhythms (https://pubmed.ncbi.nlm.nih.gov/38123819/). Nat Rev Endocrinol. 2024;20(4):228-238. Accessed 2/18/2026.
• López M, Nogueiras R. Ghrelin (https://pubmed.ncbi.nlm.nih.gov/37935121/). Curr Biol. 2023;33(21):R1133-R1135. Accessed 2/18/2026.
• Pradhan G, Samson SL, Sun Y. Ghrelin: much more than a hunger hormone (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049314/). Curr Opin Clin Nutr Metab Care. 2013 Nov;16(6):619-624. Accessed 2/18/2026.
• Society for Endocrinology (U.K.). Ghrelin (https://www.yourhormones.info/hormones/ghrelin/). Last reviewed 9/2021. Accessed 2/18/2026.

Hormonal conditions can be tricky to find and complicated to treat. The experts in endocrinology at Cleveland Clinic are here to provide the best care.

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