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  • Writer's pictureMarianne Trevorrow ND

Hormones at sea - Part 1: peri-menopause, heavy bleeding and fibroids

Updated: May 31, 2022

As an naturopathic doctor who focuses on women’s health, it is not uncommon for me to see patients in their late 30s or early 40s complaining of heavy, frequent periods. Often these are accompanied by other frustrating symptoms such as painful cramping, breast tenderness, headaches, insomnia, and irritability. As annoying as these symptoms are, however, heavy bleeding is the one most likely to cause serious problems with anemia or blood loss, and potentially lead to recommendations for uterine ablation or hysterectomy. In the meantime, women may be prescribed hormone replacement therapies such as hormone based IUDs, the 'pill' or HRT, which can themselves cause other adverse effects.

While there are certainly situations where surgical interventions become necessary, I believe a better understanding of the hormonal shifts of early perimenopause can lead to equally effective, but much less invasive treatments.

Classically, menopause has been considered a phase in women's reproductive lives where symptoms appear due to declining levels of estrogens, female hormones produced in the ovaries and also in our fatty tissues. Over the past two decades, however, women’s health researchers including Dr. Jerilynn Prior, endocrinologist and director at UBC’s Centre for Menstrual Cycle and Ovulation Research (CeMCOR) have observed both both high and erratic increases in estradiol (an ovarian form of estrogen) in thousands of menstruating women in the decade prior to menopause, resulting in many problematic symptoms including heavy bleeding.

To explain, in regularly cycling women estradiol is normally secreted from within the ovary primarily in the first part of the menstrual cycle, after menstruation occurs. . Increasing levels of estradiol during this phase helps set a chain of hormonal events in motion that leads to an ovum (egg) being secreted from a follicle within the ovary, an event known as ovulation. After that occurs, the follicle transitions to high levels of progesterone production, which prepares the uterine lining for implantation of a fertilized ovum (also known as an embryo). If implantation is not successful within a set period of time (usually between 9 and 17 days after ovulation), progesterone production in the ovary will slow down and eventually stop, which is the signal for menstruation to occur. Regular monthly bleeding resets the cycle.

All of these patterns are normally established in the 2-3 years after first menses (known as menarche), in adolescent girls and remain more or less stable through a women’s 20s and 30s, stopping only during pregnancy or breastfeeding, or if a woman is taking oral contraceptives or has a hormonal IUD. There are other problems which can disrupt regular menstrual cycling (polycystic ovarian syndrome, diabetes or thyroid problems to name a few), but with good health, most women will have more or less regular menstrual cycles until ages 37-40.

In a woman’s late 30s, however, the number of ovum-producing ovarian follicles starts to diminish, and the pituitary (brain)-ovarian hormone feedback loops involving estradiol and progesterone as well as the pituitary hormones FSH and LH start to be disrupted. Higher levels of FSH cause estradiol levels in the ovary to rise erratically--both pre- and post-ovulation--and lead to increased build up of tissue in the uterine lining. At the same time, circulating ovarian progesterone levels are also starting to fall; as the individual follicles are less likely to carry out ovulation, they also produce less progesterone, which normally balances the effects of estradiol. Low progesterone levels in themselves (even without high levels of estradiol) can also result in prolonged bleeding, especially ‘spotting’ at the beginning or end of the menstrual flow or between periods. Further complicating the picture, menstrual cycles usually become shorter, with the length from one period to the next shifting from 27-30 days to 21-24 days, on average.

The bottom line of all these hormonal changes is that women with heavy or prolonged bleeding may have high or erratically high estradiol, low progesterone or a combination of both. Fibroids may also be present, but they are the result of excess estradiol stimulating the uterine wall to produce benign growths, seldom the cause themselves of the bleeding, according to Prior's work. Fibroids can however, cause pelvic or back pain, digestive or bladder issues which can range in severity from mildly frustrating to quite debilitating. That is in addition to the problems caused by the bleeding itself.

The erratic nature of perimenopausal menstrual cycles can make it quite difficult to establish what a 'normal' or 'optimal' level of female hormone levels should be for any individual patient. This is why I routinely don't recommend 'baseline' testing, but rely instead on clinical signs including a detailed menstrual history, recent cycle length, approximate amount of flow per cycle, and other specific signs and symptoms. On the other hand, I do routinely recommend more general blood testing for anemia, thyroid or blood sugar problems, and that we review pelvic ultrasound findings (if available), as these will influence our discussion of appropriate levels of treatment and whether referrals are necessary.

Once we discuss the most likely causes and contributing factors for heavy bleeding or fibroids, we can then talk about patient preferences and decide together what interventions to use. When the question comes to use or not use hormone therapy such as natural or 'bio-identical' progesterone, we discuss patient preferences and concerns, what studies have shown, and what formulas I can prescribe here in Ontario. There are botanical medicines such as Chaste Tree, Peony or Shepherd’s Purse, or nutrient therapies such as DIM (from broccoli) that have been studied for heavy menses. In my clinical experience, these often work well individually or in blended formulas for mild to moderate excess bleeding with little or no adverse effects.

For heavier bleeding, and especially if the patient is already anemic, I’ve found bio-identical or natural progesterone given after ovulation or continuously can have dramatic effects over 2 to 3 cycles, especially when given in conjunction with ibuprofen or high dose Shepherd’s Purse every 4-6 hours on heavy bleeding days. In previous practice locations where I've had oral progesterone in my scope (WA State and BC), I've often started with that. Here in Ontario, prescribing NDs are limited to topical formulas; while I've had some success with natural compounded progesterone at 100mg-200mg a day, (cycled or continuous) I'm clear when discussing this option with patients that CeMCOR and similar studies have used the oral form. Compared with synthetic progestins however, (commonly known as Provera), natural progesterone has very few adverse effects other than occasional excess sleepiness, and very good long-term evidence of safe use.

I do want to address briefly the use of hormonal IUDs such as the Mirena or Kyleena, for heavy bleeding in perimenopause. They are also an effective option for heavy bleeding, although they also require placement by a physician (usually an OBGYN or an NP who inserts them regularly). They can last 5 years or more per placement. I have seen them work well for some women; however, clinically I have also seen pelvic, bowel and back pain issues arise from these devices, and some adverse effects from the artificial progestins including nausea, headaches, vaginal discharge and mood changes. Once inserted, they also require another visit to remove if issues arise.

Additionally to these discussions about botanical medicines and/or natural progesterone for heavy bleeding or fibroids of perimenopause, there are related hormone or deficiency issues that often need to be addressed. For example, iron supplementation is crucial to treat anemia if present and often can result in dramatic improvements in energy. Similarly, hypothyroid problems should be treated with either levothyroxine (commonly known as synthroid, also not currently in Ontario ND scope) or desiccated thyroid. For iron, I prefer the food based formulas blended with Vitamin C or plant compounds as less constipating and often equally effective than the standard ferrous gluconate formulas. Thyroid support is a longer discussion, and I will only touch on it briefly here to say that my experience is that compounded thyroid (also known as 'desiccated thyroid') is often not the best solution for hypothyroid issues, for many reasons. In those cases, I will refer patients to their prescribing family physician as needed. That being said, one very interesting recent study showed a synergistic effect of supplemented natural progesterone on serum thyroid levels, so I caution patients that it is often best to manage progesterone first, then wait to re-test thyroid levels, as they may have changed for the better.

As a follow up, I often ask patients to chart their perimenopausal cycles and symptoms on paper (CeMCOR has a great template) or with an electronic app, which allows both of us to see how both are changing over time, and whether other issues have arisen (for example, hot flashes) that also need to be addressed.

To summarize, we know that 1 in 4 women will experience symptoms such as heavy or prolonged during the perimenopausal transition, and that this can cause a lot of unnecessary misery. There is also evidence that these problems can be resolved safely and effectively with natural progesterone and/or botanical medicines, especially if the problems are identified early. All of these options can be discussed in a way that considers patient preferences and concerns in shared, informed decision making as part of a collaborative health care network. When coupled with lifestyle interventions such as plant-based diets, stress, exercise and sleep management, I believe that we can effectively support women through the entire menopausal transition and prevent many unneeded uterine ablations or hysterectomies, and their associated disabilities and costs to our health care system. And most importantly, give mid-life women back their quality of life.


For more information on progesterone or other menopausal hormone therapies, including perimenopausal symptom diaries and safety info on natural progesterone, I recommend women to the UBC CeMCOR website at:

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