Hi,
Yes, I've known a few women who felt as though they were experiencing perimenopause before their 40's. Loss of libido, or interest in sex, can be a symptom of perimenopause and also a sign of changing hormone levels among other things. To find out if you're experiencing perimenopause,you could always speak with your doctor about the 3 following tests: FSH test; Estrogen test, or TSH test. Or you could also do your own symptom check by googling "common signs of perimenopause and menopause", to see if you fit the description. Good Luck :)