Title: Dydrogesterone
CAS Registry Number: 152-62-5
CAS Name: (9b,10a)-Pregna-4,6-diene-3,20-dione
Additional Names: 10a-pregna-4,6-diene-3,20-dione; 6-dehydro-retro-progesterone; 10a-isopregnenone
Trademarks: Dufaston (ISM); Duphaston (Roxane); Gynorest (Mead Johnson); Prodel; Retrone
Molecular Formula: C21H28O2
Molecular Weight: 312.45
Percent Composition: C 80.72%, H 9.03%, O 10.24%
Literature References: Prepn: Westerhof, Reerink, Rec. Trav. Chim. 79, 771 (1960); Rappoldt, Westerhof, ibid. 80, 43 (1961).
Properties: Crystals from acetone + hexane, mp 169-170°. [a]D25 -484.5° (chloroform). uv max: 286.5 nm (e 26400).
Melting point: mp 169-170°
Optical Rotation: [a]D25 -484.5° (chloroform)
Absorption maximum: uv max: 286.5 nm (e 26400)
Therap-Cat: Progestogen.
Keywords: Progestogen.
Dymanthine Dymixal? Dynamin Dynel Dynorphin

Dydrogesterone ball-and-stick.png
Systematic (IUPAC) name
Clinical data
AHFS/Drugs.com International Drug Names
Legal status  ?
Pharmacokinetic data
Bioavailability 28%
Metabolism complete, 20-dihydrodydrogesterone (DHD) metabolite
Half-life dydrogesterone (5-7 hours) & DHD (14-17 hours)
CAS number 152-62-5 YesY
ATC code G03DB01
PubChem CID 9051
DrugBank DB00378
ChemSpider 8699 YesY
Chemical data
Formula C21H28O2 
Mol. mass 312.446 g/mol
Physical data
Melt. point 144 °C (291 °F)
Boiling point 463 °C (865 °F)
Solubility in water insoluble mg/mL (20 °C)
 N (what is this?)  (verify)

Dydrogesterone (INN, USAN, BAN), also known as 9β,10α-pregna-4,6-diene-3,20-dione, is a steroidal progestin. It is sold under the brand name Duphaston, which is manufactured by Abbott (formerly Solvay Pharmaceuticals).

Dydrogesterone was first introduced to the market in 1961, and is currently approved in over 100 countries worldwide. It has an estimated cumulative exposure of more than 10 million pregnancies.

Dydrogesterone is a potent, orally active progestogen indicated in a wide variety of gynaecological conditions related to progesterone deficiency. Although similar in molecular structure and pharmacological effects to endogenous progesterone. It is orally active at far lower doses. Its freedom from estrogenic, androgenic, anabolic, corticoid and other undesirable hormonal effects gives it additional benefits over most other synthetic progestogens.

The therapeutic use of dydrogesterone is closely related to its physiological action on the neuro-endocrine control of ovarian function, as well as on the endometrium. As such, it is indicated in all cases of relative or absolute endogeneous progesterone deficiency.

Dydrogesterone is to be withdrawn from the UK market from March 2008 for commercial reasons. Dydrogesterone was licensed for use in several indications,including threatened or recurrent miscarriage, dysfunctional uterine bleeding, and hormone replacement therapy.

Dydrogesterone has proven effective in the following conditions associated with progesterone deficiency:[citation needed]

  • menstrual disorders
  • infertility due to luteal insufficiency
  • threatened and habitual abortion. Dydrogesterone is not approved for this indication by any regulatory body in US, Canada or Australia.
  • endometriosis
  • premenstrual syndrome

Dydrogesterone has also been registered as hormone replacement therapy (HRT) to counteract the negative effects of unopposed estrogen on the endometrium in women with an intact uterus. Dydrogesterone is relatively safe and well tolerated, and does not exhibit the androgenic side effects that are common with some other progestins, like medroxyprogesterone.