Systematic (IUPAC) name
17-acetyl-17-hydroxy-6,10, 13-trimethyl-2,8,9,11,12,14,15,16- octahydro-1H-cyclopenta[ a] phenanthren-3-one
Clinical data
Trade names Megace
AHFS/ monograph
MedlinePlus a682003
Pregnancy cat. contraindicated
Legal status  ?
Pharmacokinetic data
Half-life 34 hours
CAS number 3562-63-8 YesY
ATC code G03AC05 G03DB02, L02AB01
PubChem CID 19090
DrugBank APRD01092
ChemSpider 18023 YesY
KEGG D08167 YesY
Chemical data
Formula C22H30O3 
Mol. mass 342.472 g/mol
SMILES eMolecules & PubChem
 N(what is this?)  (verify)

Megestrol is a progesterone derivative with antineoplastic properties used in the treatment of advanced carcinoma of the breast and endometrium. When given in relatively high doses, Megestrol can substantially increase appetite in most individuals, even those with advanced cancer. It is also used to boost appetite in individuals with other cancers or HIV/AIDS.

Megestrol acetate oral suspension (a form of Megestrol) is used primarily as an appetite enhancer. The method of appetite enhancement is not known, but it can cause high blood sugar.[1]

Currently, it is manufactured under the trade name Megace.[2]

Little is known about the drug's chemical interactions. Doses range from 40 mg three times a day, 30 minutes before meals, to 800 mg once a day. Side effects may include diarrhea, rash, and impotence. Males may have some feminizing effects such as gynecomastia (breast development). It is a category X U.S. Food and Drug Administration drug, which means cannot be used in pregnancy as it crosses the placenta and malignantly affects the fetus.[3]. Natural alternatives to Megace although not quite as effective are found in natural herbs such as gentian, ginger, and others [4]

It may cause adrenal insufficiency.[5]


Medroxyprogesterone acetate is on the left. Megestrol acetate is on the right.[6]

Megestrol acetate.png



  • Raney MS, Anding R, Fay V, Polk G (2000). "A pilot study to assess the use of megesterol acetate to promote weight gain in frail elderly persons residing in long-term care". J Am Med Dir Assoc 1 (4): 154–8. PMID 12816553. 
  • Deutsch J, Kolhouse JF (July 2004). "Assessment of gastrointestinal function and response to megesterol acetate in subjects with gastrointestinal cancers and weight loss". Support Care Cancer 12 (7): 503–10. doi:10.1007/s00520-004-0615-4. PMID 15064933.