There are two main types of appetite stimulants: prescription medications and natural supplements.

Prescription appetite stimulants

Prescription appetite stimulants are medications that are approved by the Food and Drug Administration (FDA) to treat loss of appetite. They work in different ways, but they all increase the level of certain chemicals in the brain that signal hunger.

Some examples of prescription appetite stimulants include Megestrol acetate (Megace): This medication is used to treat loss of appetite and weight loss caused by cancer, HIV/AIDS, and other chronic illnesses.
Dronabinol (Marinol, Syndros): This medication is a synthetic form of THC, the main psychoactive compound in marijuana. It is used to treat nausea and vomiting caused by chemotherapy, as well as loss of appetite and weight loss caused by HIV/AIDS.
Oxandrolone (Oxandrin): This medication is a synthetic steroid that is used to treat muscle wasting and weight loss caused by chronic illnesses.

Natural appetite stimulants

Natural appetite stimulants are supplements or foods that are thought to increase appetite. However, there is not as much scientific evidence to support the use of natural appetite stimulants as there is for prescription medications.

Some examples of natural appetite stimulants include Ginseng: Ginseng is a herb that is thought to increase energy levels and reduce fatigue, which may help improve appetite.

Gherkin: Gherkin is a plant that is thought to stimulate the production of ghrelin, a hormone that signals hunger.
Zinc: Zinc is a mineral that is thought to play a role in appetite regulation.

Risks and side effects

Appetite stimulants can have side effects, including Nausea and vomiting
Headache
Dizziness
Sleep problems
Increased heart rate
Increased blood pressure

It is important to talk to your doctor before taking any appetite stimulant, whether it is a prescription medication or a natural supplement. Your doctor can help you determine if an appetite stimulant is right for you and can monitor you for side effects.

Here are some additional things to keep in mind about appetite stimulants: Appetite stimulants are not a magic bullet for weight gain. They can be helpful, but they should be used in conjunction with a healthy diet and exercise program.
Appetite stimulants can be addictive. If you are concerned about addiction, talk to your doctor.
Appetite stimulants can interact with other medications you are taking. Be sure to tell your doctor about all the medications you are taking before starting an appetite stimulant.