Clinical data
Trade namesYambolap
Other namesFLI13; 7-Isopropoxyisoflavone[1]
AHFS/Drugs.comInternational Drug Names
ATC code
Legal status
Legal status
  • US: Not FDA approved
  • Rx-only in Japan
  • 7-Isopropoxy-3-phenyl-4H-chromen-4-one
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.125.854 Edit this at Wikidata
Chemical and physical data
Molar mass280.323 g·mol−1
3D model (JSmol)
  • CC(C)OC1=CC2=C(C=C1)C(=O)C(=CO2)C3=CC=CC=C3
  • InChI=1S/C18H16O3/c1-12(2)21-14-8-9-15-17(10-14)20-11-16(18(15)19)13-6-4-3-5-7-13/h3-12H,1-2H3 ☒N
 ☒NcheckY (what is this?)  (verify)

Ipriflavone (INN, JAN; brand name Yambolap) is a synthetic isoflavone which may be used to inhibit bone resorption,[2] maintain bone density and to prevent osteoporosis in postmenopausal women.[1] It is not used to treat osteoporosis. It slows down the action of the osteoclasts (bone-eroding cells), possibly allowing the osteoblasts (bone-building cells) to build up bone mass.

A clinical trial reported in 2001 that it was not effective in prevention or treatment of osteoporosis.[3]

A double-blind study reveals that ipriflavone might be effective on reducing tinnitus on otosclerosis sufferers.[4]

Ipriflavone has been described as a phytoestrogen.[5] However, this is incorrect, as the drug does not bind to or activate the estrogen receptor and shows no estrogenic effects in postmenopausal women.[6][7] The drug prevents bone loss via mechanisms that are distinct from those of estrogens.[5]


  1. ^ a b Elks J (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 651–. ISBN 978-1-4757-2085-3.
  2. ^ Civitelli R (1997). "In vitro and in vivo effects of ipriflavone on bone formation and bone biomechanics". Calcified Tissue International. 61 Suppl 1: S12-4. doi:10.1007/s002239900378. PMID 9263610. S2CID 21565791.
  3. ^ Alexandersen P, Toussaint A, Christiansen C, Devogelaer JP, Roux C, Fechtenbaum J, et al. (Ipriflavone Multicenter European Fracture Study) (March 2001). "Ipriflavone in the treatment of postmenopausal osteoporosis: a randomized controlled trial". JAMA. 285 (11): 1482–8. doi:10.1001/jama.285.11.1482. PMID 11255425.
  4. ^ Sziklai I, Komora V, Ribári O (1992). "Double-blind study on the effectiveness of a bioflavonoid in the control of tinnitus in otosclerosis". Acta Chirurgica Hungarica. 33 (1–2): 101–7. PMID 1343452.
  5. ^ a b Arjmandi BH, Birnbaum RS, Juma S, Barengolts E, Kukreja SC (January 2000). "The synthetic phytoestrogen, ipriflavone, and estrogen prevent bone loss by different mechanisms". Calcified Tissue International. 66 (1): 61–5. doi:10.1007/s002230050012. PMID 10602847. S2CID 31022310.
  6. ^ Petilli M, Fiorelli G, Benvenuti S, Frediani U, Gori F, Brandi ML (February 1995). "Interactions between ipriflavone and the estrogen receptor". Calcified Tissue International. 56 (2): 160–5. doi:10.1007/BF00296349. PMID 7736326. S2CID 24212438.
  7. ^ Melis GB, Paoletti AM, Cagnacci A, Bufalino L, Spinetti A, Gambacciani M, Fioretti P (November 1992). "Lack of any estrogenic effect of ipriflavone in postmenopausal women". Journal of Endocrinological Investigation. 15 (10): 755–61. doi:10.1007/BF03347647. PMID 1491124. S2CID 32186052.