Megestrol (Megace®, Megace-ES®)

Author: Christina Bach, MBE, LCSW, OSW-C
Last Reviewed: September 11, 2023

Pronounce: meh-JES-trol

Classification: Progestational Agent

About: Megestrol (Megace®, Megace-ES®)

Megestrol is a man-made version of progesterone, which is a type of female hormone. This medication can be used to treat breast and uterine cancers. It is also used as an appetite stimulant for people with cachexia (muscle and weight loss or wasting and anorexia associated with cancer or AIDS).

How to Take Megestrol

Megestrol comes as a tablet, a suspension (liquid), and a concentrated suspension (Megace ES) to be taken by mouth. The dosage and schedule depend on which formulation you are taking and what it is being used to treat. Take megestrol at around the same time(s) every day.

Storage and Handling

Store this medication at room temperature in the original container. If you prefer to use a pillbox, discuss this with your oncology pharmacist. Ask your oncology team where to return any unused medication for disposal. Do not flush down the toilet or throw in the trash.

Where do I get this medication?

Depending on your prescription drug coverage, this medication may be available at a retail pharmacy or through a specialty pharmacy. Your oncology team will work with your prescription drug plan to identify an in-network pharmacy for the distribution of this medication via your local pharmacy or through a mail-order specialty pharmacy.

Insurance Information

This medication may be covered under your prescription drug plan. Patient assistance may be available to qualifying individuals without prescription drug coverage. Your care team can help you access these resources if they are available.

Possible Side Effects of Megestrol

There are a number of things you can do to manage the side effects of megestrol. Talk to your care team about these recommendations. They can help you decide what will work best for you. These are some of the most common or important side effects:

Fluid Retention

Swelling of the hands, feet, and ankles due to fluid retention is a common, but not harmful, side effect. Elevating the feet may help to lessen swelling in the feet and ankles. Avoid restrictive or tight clothing that may make it harder for the fluid to drain from the hands, feet, and ankles.

Weight Gain

Weight gain as a result of an increase in food intake is a common side effect of megestrol acetate, which is why it is sometimes used to treat cachexia (muscle and weight loss or wasting and anorexia associated with cancer). This may be managed through dietary changes and exercise.

Blood Clots and Heart Attack

Megestrol can increase the risk of blood clots and heart attack. If you experience symptoms of these problems, you should contact your healthcare provider immediately or go to an emergency room. Symptoms can include swelling, redness or pain in an extremity, chest pain or pressure, difficulty breathing, pain in your arm, back, neck, or jaw, and shortness of breath.

Vaginal Bleeding

Women may experience light vaginal bleeding or spotting. Most commonly, this occurs when the medication is stopped. However, women who are already post-menopausal at the time they start megestrol acetate should report any vaginal bleeding to their oncologist, primary physician, or gynecologist.

Loss or Thinning of Scalp and Body Hair (Alopecia)

Your hair may become thin, brittle, or may fall out. This typically begins two to three weeks after treatment starts. This hair loss can be all body hair, including pubic, underarm, legs/arms, eyelashes, and nose hairs. The use of scarves, wigs, hats, and hairpieces may help. Hair generally starts to regrow soon after treatment is completed. Remember your hair helps keep you warm in cold weather, so a hat is particularly important in cold weather or to protect you from the sun.

Hot Flashes/ Sweating

There are a few things you can do to help with hot flashes. Several medications have been shown to help with symptoms, including clonidine (a blood pressure medication), low doses of certain antidepressants (such as venlafaxine and fluoxetine), and gabapentin. Talk to your healthcare team about these prescription products to determine if they are right for you.

Non-medical recommendations include:

  • Keep well-hydrated with eight glasses of water daily.
  • Drink ice water or apply an ice pack at the onset of a hot flash.
  • Wear cotton or lightweight, breathable fabrics and dress in layers so you can adjust as needed.
  • Exercise on a regular basis.
  • Try practicing meditation or relaxation exercises to manage stress, which can be a trigger.
  • Avoid triggers such as warm rooms, spicy foods, caffeinated beverages, and alcohol.


Your oncology care team can recommend medications to relieve diarrhea. Also, try eating low-fiber, bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole grain breads, cereals, and seeds. Soluble fiber is found in some foods and absorbs fluid, which can help relieve diarrhea. Foods high in soluble fiber include applesauce, bananas (ripe), canned fruit, orange sections, boiled potatoes, white rice, products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses of non-alcoholic, uncaffeinated fluid a day to prevent dehydration.


Your healthcare provider can recommend medications and other strategies to help relieve pain.

Other Side Effects

Some people may experience nausea. This typically resolves after the first few weeks of therapy. Some people experience heartburn and/or gas. Talk with your care team if this becomes bothersome.

You may experience mood changes. These can include mood swings, anxiousness, restlessness, or trouble sleeping.

If you have diabetes, your blood sugar may be higher than normal while on this medication. You may need to monitor your blood sugar more closely.

If you develop a rash, notify your care team as this can be a sign of a reaction to the medication.

Sexual & Reproductive Concerns

This medication may make you less interested in sex. In men, it may cause erectile dysfunction. Women may experience vaginal dryness.

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control is necessary during treatment, even if your menstrual cycle stops or you believe you are not producing sperm. You may want to consider sperm banking or egg harvesting if you wish to have a child in the future. Talk about these options with your oncology team. You should not breastfeed while on this medication.