During the first half of menstrual cycle LH is administered exogenously, that is, by means of medicines, it causes the following effects:
- It improves the response capacity of follicles to FSH (follicle stimulating hormone) during follicular recruitment and selection.
- The luteinising hormone or LH is necessary, like FSH, to the synthesis of oestrogens.
- It influences the increase of aromatase activity in the granulose cells and androgen production in the theca cells during preovulatory follicular maturation.
Therefore, during the first half of menstrual cycle, LH influences the normal growth or development of follicles.
The follicular development is directly related to oocyte maturation inside them, which will be later released in ovulation. For this reason, it is interesting to administer medicines with LH to women who will undergo a fertility treatment.