Birth Control Pills are synthetic hormones, and are actually much more potent compared to what is used in Hormone replacement therapy. This is necessary so they provide contraceptive effect, while HRT does not prevent ovulation or pregnancy.
Many women in their 40's use low dose birth control pills for inexpensive option to control perimenopausal symptoms and regulate cycles, and this is actually a form of rather high potency HRT in my opinion- which may not be necessary!
If there is no need for contraception, I would rather suggest women in their 40's consider nutritional and herbal remedies as their first approach to manage symptoms. Then if needed, low dose natural hormone therapy may be all that is required, rather than the potency of the synthetic Birth control pill.
We use full range of nutritional support and herbal options at our Women To Women Health Care center clinic. Our Website also offers exceptional comprehensive programs for Hormone Imbalance and more at womentowomen.com
If wish to read my full article on The Pill in Perimenopause, look further here;