5α Dihydroprogesterone

5α-Dihydroprogesterone (5α-DHP), also known as allopregnanedione, as well as 5α-pregnane-3,20-dione, is an endogenous progestogen and neurosteroid that is synthesized from progesterone. It is also an intermediate in the synthesis of allopregnanolone and isopregnanolone from progesterone. 5α-DHP is an agonist of the progesterone receptor and a positive allosteric modulator of the GABA_A receptor (albeit with an affinity for this receptor that is regarded as relatively low (in comparison to 3α-hydroxylated progesterone metabolites such as allopregnanolone and pregnanolone)). It has also been found to act as a negative allosteric modulator of the GABA_A-rho receptor. In addition, it is a weak agonist of the pregnane X receptor (PXR) (EC₅₀ >10,000 µM)), with approximately six-fold lower potency relative to its 5β-isomer, 5β-dihydroprogesterone.