Clinical data
Trade names Cur-men, Ercostrol, Geklimon, Novestrine, Vallestril (also spelled Vallestrol or Vallestryl)
Synonyms Methallenoestril; Methallenestrol; Methallenoestrol; Horeau’s acid; Allenestrol 6-methyl ether; α,α-Dimethyl-β-ethylallenolic acid 6-methyl ether; β-Ethyl-6-methoxy-α,α-dimethyl-2-naphthalenepropionic acid
Routes of
By mouth
Drug class Nonsteroidal estrogen
ATC code
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard 100.007.485 Edit this at Wikidata
Chemical and physical data
Formula C18H22O3
Molar mass 286.365 g/mol g·mol−1
3D model (JSmol)

Methallenestril (INN) (brand names Cur-men, Ercostrol, Geklimon, Novestrine, Vallestril), also known as methallenoestril (BAN) and as methallenestrol, as well as Horeau’s acid,[1][2] is a synthetic nonsteroidal estrogen and a derivative of allenolic acid and allenestrol (specifically, a methyl ether of it) that was formerly used to treat menstrual issues but is now no longer marketed.[3][4][5][6] It is a seco-analogue of bisdehydrodoisynolic acid, and although methallenestril is potently estrogenic in rats, in humans it is only weakly so in comparison.[7] Vallestril was a brand of methallenestril issued by G. D. Searle & Company in the 1950s.[8] Methallenestril is taken by mouth.[9] By the oral route, a dose of 25 mg methallenestril is approximately equivalent to 1 mg diethylstilbestrol, 4 mg dienestrol, 20 mg hexestrol, 25 mg estrone, 2.5 mg conjugated estrogens, and 0.05 mg ethinylestradiol.[9]

See also[edit]


  1. ^ Erich Heftmann (1970). Steroid Biochemistry. Academic Press. p. 144.
  2. ^ Dodds, E. C. (1949). “Synthetic aestrogens”. Journal of Pharmacy and Pharmacology. 1 (1): 137–147. doi:10.1111/j.2042-7158.1949.tb12391.x. ISSN 0022-3573.
  3. ^ C.R. Ganellin; David J. Triggle (21 November 1996). Dictionary of Pharmacological Agents. CRC Press. pp. 1295–. ISBN 978-0-412-46630-4.
  4. ^ I.K. Morton; Judith M. Hall (6 December 2012). Concise Dictionary of Pharmacological Agents: Properties and Synonyms. Springer Science & Business Media. pp. 177–. ISBN 978-94-011-4439-1.
  5. ^ John A. Thomas; Edward J. Keenan (1986). Principles of Endocrine Pharmacology. Springer Science & Business Media. pp. 171–. ISBN 978-1-4684-5036-1.
  6. ^ Herbai G, Ljunghall S (1983). “Normalization of hypercalcaemia of primary hyperparathyroidism by treatment with methallenestril, a synthetic oestrogen with low oestrogenicity”. Urol. Int. 38 (6): 371–3. doi:10.1159/000280925. PMID 6659184.
  7. ^ Raymond Eller Kirk; Donald Frederick Othmer (1980). Encyclopedia of chemical technology. Wiley. p. 670. ISBN 978-0-471-02065-3.
  8. ^ Library of Congress. Copyright Office (1965). Catalog of Copyright Entries. Third Series: 1963: July-December. Copyright Office, Library of Congress. pp. 1984–.
  9. ^ a b Swyer GI (April 1959). “The oestrogens”. Br Med J. 1 (5128): 1029–31. doi:10.1136/bmj.1.5128.1029. PMC 1993181. PMID 13638626.