This is the 18445th most frequent Russian word.
эстрогенов
The Russian word "эстрогенов" means "of estrogens" in English, referring to the plural genitive form of the hormone estrogen.
In this sentence, 'эстрогенов' is in the genitive plural form, showing possession or relation to the word 'количество' (amount).
Количество эстрогенов может варьироваться в зависимости от возраста человека.
The amount of estrogens may vary depending on a person's age.
Here, 'эстрогенов' is also in the genitive plural form, used with the preposition 'влияние' (effect on), emphasizing the object of influence.
Медик исследовал влияние эстрогенов на организм.
The doctor studied the effect of estrogens on the body.
In this instance, 'эстрогенов' expresses a lack or insufficiency regarding the neutral notion represented by 'недостаток' (deficiency).