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.