Menstruum as a noun is any solvent used for extracting medicinal compounds from plants etc. while Menstruation as a noun is the periodic discharging of the menses, the flow of blood and cells from the lining of the uterus in females of humans and other primates.
Part of speech: noun
Definition: Any solvent used for extracting medicinal compounds from plants etc.
Part of speech: noun
Definition: The periodic discharging of the menses, the flow of blood and cells from the lining of the uterus in females of humans and other primates.
We hope you now know whether to use Menstruum or Menstruation in your sentence.