Premature ovarian failure can occur as early as age 27, with early menopause defined between 40-45 and premature menopause/insufficiency before age 40.

“the earliest you've ever had a patient come in who entered menopause what's the latest you personal patient 27 and she came in just a couple months ago so she had a special condition we call premature ovarian failure and she had found me on social media and wanted to come just to make sure she was doing everything right and so early menopause is defined as between the ages of 40 and 45 and then premature menopause or pre premature ovarian insufficiency it's not a complete failure for most women but it is very very low is any time before the age of 40”