Androsterone

[3][4] Androsterone is also known to be an inhibitory androstane neurosteroid,[5][6] acting as a positive allosteric modulator of the GABAA receptor,[7] and possesses anticonvulsant effects.

[8] The unnatural enantiomer of androsterone is more potent as a positive allosteric modulator of GABAA receptors and as an anticonvulsant than the natural form.

[11] Spectrometric studies identify androsterone as the main backdoor androgen in the human male fetus.

Circulating levels are sex dependent, DHT being essentially absent in the female, in which titres of backdoor intermediates also are very low.

Androsterone has been shown to naturally occur in pine pollen, celery, truffles and is well known in many animal species.