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Quick facts
- How it is given
- oral
- Type
- human prescription drug
- RxNorm ID
- 860225
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
INDICATIONS & USAGE Megestrol acetate oral suspension is indicated for the treatment of anorexia, cachexia, or an unexplained, significant weight loss in patients with a diagnosis of acquired immunodeficiency syndrome (AIDS).
About this medicine
DESCRIPTION Megestrol Acetate Oral Suspension, USP contains megestrol acetate, a synthetic derivative of the steroid hormone, progesterone. Megestrol acetate is a white, crystalline solid chemically designated as 17-Hydroxy-6-methylpregna-4,6-diene-3,20-dione acetate. Solubility at 37°C in water is 2 mcg per mL, solubility in plasma is 24 mcg per mL. Its molecular weight is 384.52. The chemical formula is C 24 H 32 O 4 and the structural formula is represented as follows: Megestrol acetate oral suspension is supplied as an oral suspension containing 40 mg of micronized megestrol acetate per mL. Megestrol acetate oral suspension contains the following inactive ingredients: citric acid, lemon-lime flavor (propylene glycol, ethyl alcohol, natural flavor), propylene glycol, purified water, sodium benzoate, sodium citrate, sucrose and xanthan gum. Image 1
Who should not take it
CONTRAINDICATIONS History of hypersensitivity to megestrol acetate or any component of the formulation. Known or suspected pregnancy.
Warnings
WARNINGS Megestrol acetate may cause fetal harm when administered to a pregnant woman. For animal data on fetal effects, (see PRECAUTIONS: Carcinogenesis, Mutagenesis, and Impairment of Fertility: Impairment of Fertility ). There are no adequate and well-controlled studies in pregnant women. If this drug is used during pregnancy, or if the patient becomes pregnant while taking (receiving) this drug, the patient should be apprised of the potential hazard to the fetus. Women of childbearing potential should be advised to avoid becoming pregnant. Megestrol acetate is not intended for prophylactic use to avoid weight loss. (See also PRECAUTIONS: Carcinogenesis, Mutagenesis, and Impairment of Fertility ) The glucocorticoid activity of megestrol acetate oral suspension has not been fully evaluated. Clinical cases of new onset diabetes mellitus, exacerbation of preexisting diabetes mellitus, and overt Cushing’s Syndrome have been reported in association with the chronic use of megestrol acetate. In addition, clinical cases of adrenal insufficiency have been observed in patients receiving or being withdrawn from chronic megestrol acetate therapy in the stressed and non-stressed state. Furthermore, adrenocorticotropin (ACTH) stimulation testing has revealed the frequent occurrence of asymptomatic pituitary-adrenal suppression in patients treated with chronic megestrol acetate therapy. Therefore, the possibility of adrenal insufficiency should be considered in any patient receiving or being withdrawn from chronic megestrol acetate therapy who presents with symptoms and/or signs suggestive of hypoadrenalism (e.g., hypotension, nausea, vomiting, dizziness, or weakness) in either the stressed or non-stressed state. Laboratory evaluation for adrenal insufficiency and consideration of replacement or stress doses of a rapidly acting glucocorticoid are strongly recommended in such patients. Failure to recognize inhibition of the hypothalamic-pituitary-adrenal axis may result in death. […]
Reported side effects
ADVERSE REACTIONS Clinical Adverse Events Adverse events which occurred in at least 5% of patients in any arm of the two clinical efficacy trials and the open trial are listed below by treatment group. All patients listed had at least one post baseline visit during the 12 study weeks. These adverse events should be considered by the physician when prescribing megestrol acetate oral suspension. ADVERSE EVENTS % of Patients Reporting Megestrol Acetate, mg/day No. of Patients Trial 1 (N=236) Trial 2 (N=87) Open Label Trial Placebo 0 N=34 100 N=68 400 N=69 800 N=65 Placebo 0 N=38 800 N=49 1200 N=176 Diarrhea 15 13 8 15 8 6 10 Impotence 3 4 6 14 0 4 7 Rash 9 9 4 12 3 2 6 Flatulence 9 0 1 9 3 10 6 Hypertension 0 0 0 8 0 0 4 Asthenia 3 2 3 6 8 4 5 Insomnia 0 3 4 6 0 0 1 Nausea 9 4 0 5 3 4 5 Anemia 6 3 3 5 0 0 0 Fever 3 6 4 5 3 2 1 Libido Decreased 3 4 0 5 0 2 1 Dyspepsia 0 0 3 3 5 4 2 Hyperglycemia 3 0 6 3 0 0 3 Headache 6 10 1 3 3 0 3 Pain 6 0 0 2 5 6 4 Vomiting 9 3 0 2 3 6 4 Pneumonia 6 2 0 2 3 0 1 Urinary Frequency 0 0 1 2 5 2 1 Adverse events which occurred in 1% to 3% of all patients enrolled in the two clinical efficacy trials with at least one follow-up visit during the first 12 weeks of the study are listed below by body system. Adverse events occurring less than 1% are not included. There were no significant differences between incidence of these events in patients treated with megestrol acetate and patients treated with placebo. […]
Interactions with other medicines
DRUG INTERACTIONS Pharmacokinetic studies show that there are no significant alterations in pharmacokinetic parameters of zidovudine or rifabutin to warrant dosage adjustment when megestrol acetate is administered with these drugs. The effects of zidovudine or rifabutin on the pharmacokinetics of megestrol acetate were not studied. Megestrol acetate may interact with warfarin and increase International Normalized Ratio (INR). Closely monitor INR in patients taking megestrol acetate and warfarin. Animal Toxicology Long-term treatment with megestrol acetate may increase the risk of respiratory infections. A trend toward increased frequency of respiratory infections, decreased lymphocyte counts, and increased neutrophil counts was observed in a two-year chronic toxicity/carcinogenicity study of megestrol acetate conducted in rats.
If too much is taken
OVERDOSAGE No serious unexpected side effects have resulted from studies involving megestrol acetate oral suspension administered in dosages as high as 1200 mg/day. In post-marketing experience, limited reports of overdose have been received. Signs and symptoms reported in the context of overdose included diarrhea, nausea, abdominal pain, shortness of breath, cough, unsteady gait, listlessness, and chest pain. There is no specific antidote for overdose with megestrol acetate oral suspension. In case of overdose, appropriate supportive measures should be taken. Megestrol acetate has not been tested for dialyzability; however, due to its low solubility, it is postulated that dialysis would not be an effective means of treating overdose.
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This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 5 January 2026. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.