Ghrelin is a hormone your stomach 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 significantly restrict their calorie intake have high ghrelin levels.
Often known as the “hunger hormone,” ghrelin has numerous functions in addition to telling your brain you’re hungry. For example, ghrelin:
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
Ghrelin and leptin are two of many hormones that control your appetite and fullness. They’re involved in the vast network of pathways that regulate your body weight. Leptin decreases your appetite, while ghrelin increases it.
Ghrelin is made in your stomach and signals your brain when you’re hungry. Your fat cells produce leptin. Leptin lets your brain know when you have enough energy stored and feel “full.”
Ghrelin plays a role in the short-term control of appetite while leptin controls long-term weight control.
Ghrelin has several key functions. The hormone:
Your stomach releases ghrelin when it’s empty or mostly empty. Ghrelin levels are typically highest right before mealtimes.
Ghrelin levels increase when your stomach is empty. Your body releases ghrelin to let your brain know when it’s time to eat. Then, when you eat, your ghrelin levels decrease.
Some conditions can lead to chronically low or high ghrelin:
Ghrelin levels are usually lower in people who have obesity. Some researchers think this connection could mean that people who have obesity have bodies that are naturally more sensitive to ghrelin. The theory is that these individuals may feel much hungrier with lower levels of ghrelin.
Certain gastrointestinal diseases are also associated with low ghrelin, including:
People may have increases in ghrelin levels if they restrict their caloric intake, such as while on a restrictive diet. High ghrelin may also be associated with biological and genetic conditions such as:
Gastric bypass surgery and sleeve gastrectomy are two of the surgical therapies for severe obesity. People have sustained lower levels of ghrelin after these operations which are thought to be responsible for long-term weight control. A reduced stomach size is thought to be one of the causes of weight loss after bariatric surgery and is responsible for the lower ghrelin levels.
You can keep ghrelin and other hormone levels healthier by practicing good lifestyle habits, such as:
No specific food suppresses ghrelin. In general, eating foods high in healthy carbohydrates (such as whole grains) and protein can lower your ghrelin levels.
Ghrelin levels tend to rise and fall with how much you eat. Ghrelin may decrease when you are hydrated and increase when you’re dehydrated.
The types of foods you eat affect ghrelin. For example, eating foods high in protein or healthy carbs lower ghrelin levels more than eating foods high in fat.
A note from Cleveland Clinic
Ghrelin is a hormone produced in your stomach. Your stomach releases ghrelin when it’s empty to signal your brain that it’s time to eat. Ghrelin is often called the hunger hormone, but it does more than control hunger. It also signals your pituitary gland to release growth hormones, plays a role in insulin release and protects your cardiovascular health.
Last reviewed by a Cleveland Clinic medical professional on 04/21/2022.
Learn more about our editorial process.