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Changes in appetite and weight can be a sign of certain health conditions. If you start to notice a decreased appetite and unintentional weight loss, it’s important that you talk to your health professionals to understand the underlying cause. 

If you are struggling with appetite loss due to a health condition, your doctor may prescribe an appetite stimulant to increase appetite to  promote weight gain. 

Continue reading to learn more about the different types of appetite stimulation medications, how they work, possible side effects, and tips on increasing appetite with non-pharmacological (or non-drug) approaches. 

Overview of Appetite Stimulants

How They Work

If you are experiencing unintentional weight loss due to a decreased appetite, your doctor may prescribe an appetite stimulant. These medications work by targeting the mechanisms involved in hunger and satiety. They can be used in combination with healthy lifestyle changes, such as eating frequent small meals to ensure your body gets enough calories to be well-nourished. 

Common Uses

• Cachexia (extreme weight loss related to a chronic illness such as cancer and its treatment).

• HIV/AIDS-related weight loss.

• Loss of appetite in people with eating disorders.

• Severe weight loss after surgery, trauma, or infections.

Types of Appetite Stimulants: What Drugs Are Used to Increase Appetite?

Types of drugs prescribed for increasing appetite include:

• Prescription appetite stimulant drugs

• Anabolic steroids - this type of appetite stimulant is no longer available in the U.S. as the FDA withdrew its approval in June 2023

• Over-the-counter herbal remedies and nutritional supplements

Appetite stimulant drugs may lead to an increase in the desire for food intake. They improve the overall nutritional status of patients and weight loss issues related to other medical complications. The following medications are commonly prescribed appetite stimulants:

Megestrol Acetate (Megace)

Megestrol acetate (Megace) is an FDA-approved synthetic progesterone for the treatment of advanced uterus and breast cancer. 

However, megestrol is often used off-label to treat anorexia or cachexia, which is chronic illness-related extreme weight loss. For example, megestrol is used as an appetite stimulant to promote weight gain for cancer patients. Megestrol is also prescribed for off-label use in pediatric patients with cachexia due to head and neck cancer. 

Dronabinol (Marinol) 

Dronabinol (Marinol) is a cannabinoid (artificial form of cannabis); it is one of the commonly prescribed appetite-stimulating medications for HIV/AIDS patients experiencing weight loss to help them boost body weight. Dronabinol is also used to alleviate nausea and vomiting in cancer patients undergoing chemotherapy.

Mirtazapine (Remeron)

Mirtazapine (Remeron) is an antidepressant. This drug can be used to stimulate appetite in patients with major depressive disorder and eating disorders, such as anorexia nervosa. 

Keep in mind that using mirtazapine as an appetite stimulant is an off-label use. The dosage of mirtazapine used in clinical studies to stimulate appetite in cancer patients is 7.5 milligrams (mg) to 30 mg orally once daily. 

Cyproheptadine (Periactin)

Cyproheptadine is an antihistamine used to relieve symptoms of seasonal allergies. It is also commonly prescribed to relieve headaches and motion sickness, as well as to increase appetite. Unlike other antihistamines such as cetirizine (Zyrtec) and fexofenadine (Allegra), cyproheptadine is only available by prescription. Talk to your doctor if you have questions about other over-the-counter (OTC) antihistamines that can also be beneficial as an appetite stimulant to help you gain weight. This medication can help your child eat more meals and gain weight. 

You should always consult your doctor or pharmacist before using cyproheptadine. Apetamin, cyproheptadine-containing products that are illegally imported into the U.S. from overseas, can cause liver disease and heart problems. 

Oxandrolone (Oxandrin) 

The FDA has approved the steroidal drug oxandrolone for use in patients who experience unexplained weight loss after surgery, severe infection, and trauma. This drug reduces sarcopenia (muscle wasting), promotes muscle growth, and stimulates appetite. However, this medication is no longer available in the U.S. as the FDA withdrew its approval in June 2023.

Note: The above information is not a substitute for a professional medical consultation. Please review the fact sheet provided by the drug manufacturer and talk to your doctor or pharmacist for further information.

Common Questions

Is It Okay To Take an Appetite Stimulant?

It is normal to experience slight fluctuation in appetite, leading to weight gain or weight loss. However, if you experience loss of appetite over a prolonged period, you should talk to your doctor to determine the underlying cause. 

In many cases of chronic illnesses, your doctor will help you determine if an appetite stimulant will benefit you. Loss of appetite is a sign of an underlying health condition. Therefore, treating the loss of appetite only fixes the symptoms. Addressing the root problem to correct the underlying health condition is essential to improving the appetite in the long run. 

What Is The Best Appetite Stimulant?

The best appetite stimulant depends on the reason for your loss of appetite. Your healthcare team will prescribe the most appropriate medicine for you. For example, loss of appetite in people with an eating disorder may be best treated with antidepressants like Remeron (active ingredient: mirtazapine), which is an antidepressant. Appetite loss related to HIV/AIDS may benefit from Marinol (active ingredient: dronabinol).

Corticosteroids like dexamethasone or prednisone reduce inflammation in various health conditions. While these medications can cause weight gain because they increase hunger and retain fluid weight, they are not generally used as appetite stimulants.

Effectiveness of Appetite Stimulants

Studies examining the effectiveness of appetite stimulant drugs have shown mixed results. The potentially serious side effects of these drugs may, therefore, preclude their use for stimulating appetite.

• A systematic review of more than 1,000 studies found that megestrol acetate increased appetite in approximately 25% of patients and resulted in weight gain in approximately 10% of patients but did not significantly improve quality of life.

• The efficacy of synthetic THC (dronabinol) on appetite and weight maintenance in cancer patients has been mixed. A multicenter randomized, double-blind trial found that it did not significantly improve appetite.

• A randomized clinical trial in patients with advanced lung cancer found no difference in appetite between patients who received mirtazapine and placebo (inactive drug). However, the mirtazapine group had significantly increased energy intake through fat intake which is a critical source of energy. 

• Studies have shown that cyproheptadine is a safe appetite stimulant in patients with poor appetite. This drug is well tolerated without reports of any serious side effects.

Comparison of Different Appetite Stimulants

A retrospective cohort study of hospitalized patients compared dronabinol, megestrol, and mirtazapine effects on appetite in the inpatient setting. Each drug resulted in improved meal intake by about 17%. Almost half of all patients had an improvement in diet after starting these appetite-stimulating medicines. No serious adverse effects were reported. There was no significant difference between dronabinol, megestrol, or mirtazapine in terms of the ability to stimulate appetite.

Safety and Risks

Potential Side Effects of Megestrol Acetate

Megestrol acetate can raise the risk of blood clots. Tell your doctor right away if you notice chest pain, trouble breathing, or swelling of the arms or legs. Megestrol is not recommended for use in pregnant women as it can cause birth defects. Tell your doctor if you are pregnant before taking this medication.  

Potential Side Effects of Dronabinol

Dronabinol can cause unwanted side effects such as worsening mental illness, such as psychosis, paranoia, and depression. Inform your doctor if you experience changes in mood or behaviors, dizziness, rapid heartbeat, headaches, or vision problems while taking dronabinol. Tell your doctor if you have a heart condition, as dronabinol can also affect blood pressure in some older adults.  

Potential Side Effects of Mirtazapine

Common side effects of mirtazapine are drowsiness, dizziness, increased appetite, and weight gain. This medication should not be given to children younger than 18 years old. Tell your doctor if you notice any of the following worsening symptoms:

• Mood or behavior changes, anxiety, worsening depression 

• Sleep problems

• Symptoms of mania such as recklessness, extreme happiness or sadness, decreased need for sleep, racing thoughts

Potential Side Effects of Cyproheptadine

Cyproheptadine can come with side effects, including fatigue, dry mouth, sun sensitivity, dizziness, headache, stomach pain, and diarrhea.

Potential Side Effects of Oxandrolone

Oxandrolone can affect blood cholesterol levels, leading to an increased risk of coronary artery disease. Notably, this medication is no longer available in the U.S. as the FDA withdrew its approval in June 2023. 

Drug Interactions

Taking other drugs at the same time as an appetite-stimulating medicine can affect how the medicines work and increase the risk of severe adverse effects. 

To lower the risk of drug interactions, give your doctor and pharmacist a complete list of your medications, including prescription drugs, over-the-counter medications, dietary supplements, and herbal products before starting an appetite stimulating medicine.

Use of Appetite Stimulants for Specific Populations

Children

Appetite stimulants that are used in adults are also used in children with chronic conditions like cancer and cystic fibrosis. However, there is limited safety and dosing information for this population. 

Elderly

Megestrol acetate is considered potentially inappropriate for use in elderly adults because of its minimal effect on weight gain and the potential for thrombotic events (blood clots) associated with an increased risk of death. 

Dronabinol has not been well studied in older adults. Studies have found that long-term care residents tolerate dronabinol but do not have significant weight gain on this drug.

The use of cyproheptadine in older adults is limited due to its anticholinergic effects.

Cancer Patients

Progestin agents like megestrol acetate are the most studied in cancer patients. Other options include cannabinoids and cyproheptadine. Cannabinoids like dronabinol (Marinol) are preferred in many cases because this medication also helps to alleviate nausea and vomiting in cancer patients. 

Further Reading 

Role of Appetite in Overall Health

Appetite, meaning the motivation to eat to fulfill the body’s energy requirements, is a pivotal element for weight regulation. Appetite and hunger are mainly controlled by a complex system, including a part of the brain called the hypothalamus, in addition to the gastrointestinal system and certain natural hormones in the body. While temporary or situational effects of appetite suppression due to environmental factors or stressors may not immediately result in weight loss, a loss of appetite over an extended period of time can result in weight loss, a lack of necessary nutrients, weakness, malnourishment, and many other health complications. 

Can a Poor Appetite Cause Health Problems?

A poor appetite is characterized by a loss of interest in eating food and can cause health issues over time. Without the proper nutrition and energy from frequent meals, the body cannot function adequately, and this will cause low levels of energy and fatigue. Eventually, it can lead to loss of bone strength and a weakened immune system. So, losing weight does not only result in weakness and fatigue. It also interferes with the body’s ability to fight off infection. 

Poor appetite can also cause digestive issues, making it harder for your body to process food, resulting in gas, bloating, stomach pain, and irregular bowel habits.

Medical Conditions That Can Cause Poor Appetite

A loss of appetite can happen to anyone for a variety of reasons, but sometimes, the reason is an underlying health issue. If you begin to notice your meal intake lessen, consider talking to your doctor to rule out a potential health condition.  

Some common causes of short-term appetite loss can include the common cold or flu, respiratory infections, constipation, acid reflux, food poisoning, food allergies, stress, and medication side effects.  

Undergoing hormonal fluctuations such as menopause and pregnancy can affect appetite and metabolism. During pregnancy, some women may experience a loss of appetite, especially if morning sickness is also present. For menopausal women, a change in appetite may happen. This can be an increase in hunger or an appetite loss. While a loss in appetite during menopause is not common, when it occurs, it is typically due to stress, anxiety, and mood problems. 

However, there are some more serious health conditions that may be responsible for your lack of interest in food. The following are more serious and long-term conditions that can lower your appetite and cause you to lose weight:

• Irritable bowel syndrome (IBS) or Crohn’s disease

• Asthma

• Diabetes

• Chronic liver or kidney disease

• HIV and AIDS

• Underactive thyroid (hypothyroidism)

• Overactive thyroid (hyperthyroidism)

• COPD

• Heart failure

• Stomach cancer

• Mental health conditions such as depression, anxiety, and anorexia nervosa

Loss of appetite may also be a possible side effect of some medications, like antibiotics, CNS (central nervous system) stimulants, chemotherapy, immunotherapy, and radiation therapy drugs. 

How Hormones Affect Appetite and Weight

The body’s response to hunger is determined by various hormones. Hunger, the desire to seek food, is controlled by a hormone called ghrelin (also called the hunger hormone). Satiety, the feeling of fullness, is controlled by certain hormones like leptin, cholecystokinin (CKK), and peptide YY. Peptide YY is produced in the gastrointestinal tract. It reduces appetite and promotes satiety. Neuropeptide Y stimulates food intake, specifically carbohydrate intake, increases motivation to eat, and helps augment meal size by delaying satiety.

Notably, the “hunger hormone” ghrelin also plays many vital roles in the body besides signaling hunger. Ghrelin also:

• Regulates blood sugar and the release of insulin in the body

• Signals the pituitary gland to produce growth hormones

• Promotes muscle health and bone formation

Natural Remedies for Increasing Appetite

Medications are just one method of overcoming poor appetite, especially in those with an underlying health condition. Certain supplements, lifestyle changes, and other factors can improve appetite in people without needing medication.

Vitamins and Supplements

Certain vitamins and minerals, such as zinc and vitamin B, can help increase appetite. Nutritional supplements, such as protein shakes, can also provide extra calories and nutrients to help you eat enough calories to gain weight.

Fish oil supplementation is a rich source of omega-3 fatty acids. These fatty acids are essential fats and may work as appetite stimulants while also improving heart, brain, and eye functions and joint health.  

High doses of fish oil supplements may lead to bleeding. Monitoring of patients using blood thinning medications is essential to ensure their safety. Other side effects may include improper digestion, diarrhea, or a fishy taste.

Herbal Appetite Stimulants

Some herbs and natural compounds, such as ginger, fenugreek, and certain essential oils, are believed to have appetite-stimulating properties. More research is needed, but they may reduce unexplained weight loss and increase appetite in healthy adults. 

It is important to know that herbal and natural supplements are not regulated by the FDA. Talk to your doctor or pharmacist to prevent unwanted side effects and harmful drug interactions. 

Lifestyle Changes: How Can I Stimulate My Appetite?

If you want to increase your appetite and body weight but are unsure about taking medications, you can try to make some healthy diet and lifestyle changes first. 

Some ways you can naturally stimulate appetite include:

• Increase physical activity as tolerated (daily exercise, walking, weight lifting).

• Manage stress and anxiety through activities like meditation and deep breathing.

• Get good sleep, as lack of sleep may result in loss of appetite.

• Avoid smoking, use of tobacco, and alcohol consumption. These habits can suppress appetite, leading to weight loss.

Dietary Adjustments

• Add healthy fats and proteins to your diet to increase calories and avoid further weight loss.

• Eat frequent small meals throughout the day.

• Try grocery delivery services to ensure you have enough healthy foods at mealtime and healthy ingredients while preparing food.

• Eat meals in a communal setting.

• Drink water 30 minutes before eating a meal in order to avoid the feeling of fullness.

• Drink herbal teas before meals to promote appetite and hunger.

• Consult a dietitian.