Both caffeine and coffee have been shown to lower estradiol levels in premenopausal women, and low estrogen can lead to loss of bone, the plumpness in your skin going away, and your libido diminishing to just name a few[i].
Caffeine boosts energy temporarily because it raises your cortisol, but as I explain in my program, high cortisol can block progesterone receptors and therefore lower your progesterone, leading to PMS. Whilst caffeine has not been shown to lower progesterone levels in women who are having monthly cycles, two studies have linked caffeine with other PMS symptoms[ii].
If you want to know the signs of low progesterone, check out this blog post here.
Additionally, if you have insulin-resistant PCOS (there are 4 different types of PCOS) then you definitely want to eliminate caffeine until you’ve gotten your insulin levels in check. Even small increases in cortisol from caffeine, can raise blood sugar levels and increase insulin resistance, worsening PCOS[iii].