Hormone therapy (HT) is the general term used to describe the various hormonal treatments commonly used to manage and relieve menopause-related symptoms such as hot flashes, night sweats, headaches, sleep disturbance, vaginal dryness, mood swings and irritability, among others [1–6].   During the menopause transition (a.k.a. perimenopause), these symptoms occur as a result of low estrogen and progesterone levels in the body [1–6]. Hormone therapy may be described as MHT (menopausal hormone therapy) when it is prescribed as a supplemental form of estrogen and/or progesterone hormones for women experienceing a normal perimenopause transition, or during the post-menopause year. Hormone Replacement Therapy (HRT) is the medical term for when hormone therapy is prescribed as a replacement of the natural hormone levels of estrogen and/or progesterone that decreased to very low or insufficient levels for women in the pre-menopause stage (below age 40), or early perimenopause stage (below age 45), or for women who have had a hysterectomy or oophorectomy (removal of one or both ovaries, but not the uterus). 

HT is often prescribed as the first line treatment of vasomotor symptoms such as hot flashes and night sweats in menopausal women who have no history of other medical conditions [1,2,7].  However HT might not be recommended if you have had one or more of the following health conditions [1,2,7]:

• Breast cancer

• Coronary artery disease

• Thromboembolic disease (Deep vein thrombosis)

• Stroke

• Undiagnosed vaginal bleeding

• Endometrial cancer

• Endometriosis

Estrogen deficiency due to menopause can cause significant loss of bone mass, resulting in osteoporosis [1,8,9]. Osteoporosis is a systemic skeletal condition seen by low bone density, deterioration of the bone tissue and decreased bone strength which leads to bone fragility and increased risk of fractures [1,8,9]. HT is normally used as a secondary line of treatment for the prevention of osteoporosis in menopaused women [1,8,9]. However a recent article published in the Canadian Medical Association Journal reported that HT is the treatment of choice for peri-menopausal women who are in their 40s and 50s experiencing vasomotor symptoms (i.e., hot flashes and night sweats) within 10 years of their final menstrual period [1]. The duration and dosage of treatment is dependent on the individual's needs and is no longer recommended to be limited to the first 5 years of taking HT [1].

How does Hormone  Therapy (HT) Work?

The main purpose of HT during menopause is to restore estrogen and progesterone hormones in females to normal levels [10]. Usually, HT treatments are delivered as a combination of estrogen and a progestin – which is the term used for the synthetic version of the natural hormone progesterone [1,6,11]. Estrogen is prescribed to manage menopause symptoms, while progestins work primarily to protect the tissue lining of the uterus from becoming enlarged or inflamed, or to prevent endometrial cancer, and also in managing menopause symptoms [1,6,11]. The types of estrogen hormone used in HT can include estradiol (most prescribed), ethinylestradiol, mestranol, esterified estrogens (estradiol valerate), estropipate, and conjugated equine estrogens (CEE) [11]. The types of progesterone hormone used in HT can include a progestin (synthetic progesterone) such as medroxyprogesterone acetate (MPA), levonorgestrel, norethindrone, desogestrel, micronized progesterone and others [13,14]. 

For those who are scientifically curious, here is a visual representation of the structural differences between naturally occurring estrogens and progesterone and their synthetic counterparts. 

Figure 1. Chemical structures of natural and synthetic estrogens and progesterone.

Please consult with your medical doctor or naturopathic doctor to discuss the benefits and risks of taking Hormone Therapy for managing your menopause hormonal health.

Types of Hormone Therapy and Delivery Formats [1,3,15]: 

1. Estrogen-Progestin Combination – for individuals that have a uterus

   • Oral pills

   • Transdermal patch (applied outside of upper arm, lower stomach, or top of the buttocks)

2. Estrogen Only – for individuals who have had a total hysterectomy [1]​

   • Oral pills

   • Transdermal patch (applied to outside upper arm, lower stomach, or top of the buttocks)

   • Transdermal gel (applied to the forearm)

   • Transdermal spray (applied to the forearm)

   • Vaginal creams, tablets, or rings

     
     

3. Progestin Only – for individuals with an adverse reaction to estrogen [16]

   • Oral pills

   • Intrauterine device (IUD) (e.g., Levonorgestrel , commercially sold as Mirena®) [1,17,18]

​For individuals that are recommended to take progesterone but are not interested in taking synthetically made progestin, there is the option of taking oral micronized progesterone that is extracted from a species of yams (Prometrium®) [19].

Benefits of Hormone Therapy [1,2,6]

• ​Improves up to 90% of vasomotor symptoms in patients with moderate to severe hot flashes [1].

• Improves sleep quality by lowering mood disturbances and reducing night sweats

• Relieves vaginal dryness (a.k.a. vaginal atrophy) and increases libido (sexual drive)

• Lowers the risk of osteoporosis-related fractures such as hip fractures (up to 34% decreased risk), vertebral fractures (up to 23% decreased risk) [1]

• Improves insulin sensitivity and reduces the risk of type II diabetes

• Reduces the risk of coronary artery disease in women who start HRT before their 60’s.

• Improves overall quality of life, sleep, and relationships with family, spouse/partners, friends [1,2,20]

Risks of Hormone Therapy

Over the past two decades, HT has been the subject of many medical debates and controversies because of the flawed conclusions that were reported as outcomes from a large USA population health research study published in 2002 known as the Women’s Health Initiative (WHI) study [1,21–23].  The authors of the WHI study reported that HT could lead to detrimental health risks, and specifically higher risk of breast cancer, than health benefits for women aged 65 years or older, who were the subject of the study [1,21–23]. These negative results were widely publicized among the medical community and popular media, which ensued panic among women patients, and triggered lawsuits [1–3,7,11,22]. 

However, by 2006 the conclusions of the WHI study had been debunked because of new clinical studies which proved that the use of HT by younger women entering perimenopause or in the early post-menopause years, led to a reduced risk of coronary disease, osteoporosis, endometrial cancer, and a lowered risk of poor cognitive health [1–3,7,11,22]. Unfortunately a huge generation of ‘babyboom’ and ‘GenX’ women, many of whom are currently in their 50s to 80s, were negatively impacted by the false outcomes originally reported from the WHI study, since many physicians in the Western medicine fields were advised by their professional medical associations to avoid prescribing HT to women who could have greatly benefited from this therapy during their menopausal journey [1–3,7,11,22]. In the 10-15 years subsequent to the poorly-studied conclusions of the WHI trial, a generation of physicians and obstetrician-gynecologists had unfortunately received an inadequate level of training about hormone therapies for treating pre-menopause, perimenopause and post-menopause symptoms.

It is important to note that from both the 2002 WHI study and new clinical studies, it remains true that for women over the age of 60, HT can present a greater risk of health complications rather than benefit, so it is usually not recommended to women in this older age group [1–3,6,7,11,20,22,24]. 

There has also been research that has associated estrogen-progestin combination HT with an increased risk of dementia and Alzheimer’s disease even in women aged 55 and younger although more research needs to be done in order to determine if the increased risk comes from HT or from a natural predisposition to these diseases [25]. 

Hormone Therapy and Cancer

A review of all clinical studies looking at HT and cancer patients and survivors published in the Cancer Journal in 2022, found that out of 25 studies published between 1980 and 2013, only 1 study (the hormonal replacement therapy after breast cancer (HABITS) trial) demonstrated an increased risk of cancer recurrence (colorectal and local cancer but not breast cancer) [24,26].  However, that study was prematurely stopped in 2003 and so its results were misinterpreted and misrepresented to mean that HT should not be recommended to cancer survivors [24].

Despite the above stated research, according to the North American Menopause Society (NAMS), for breast cancer survivors, the use of systemic estrogen HT (i.e., estrogen that is delivered orally or transdermally and which circulates in the bloodstream) is not recommended for relief of vasomotor symptoms [27]. 

However, both the NAMS and the Canadian Menopause Society acknowledge that estrogen HT is associated with little impact on breast cancer risk and that with prolonged use, there is a slight increase in risk [28,29]. In order to minimize risk, the NAMS recommends starting with the lowest effective dose of estrogen for the shortest time period possible [28]. 

Side effects of Hormone Therapy

​Common side effects of HT may include, but are not limited to [1,2,6]:

• Headache

• Vaginal bleeding (or breakthrough bleeding)

• Premenstrual-like symptoms such as breast-tenderness, bloating, mood swings can persist within the first few months of starting HRT [13]

• Breast pain (Mastalgia)

• Weight change

• Cholecystitis (inflammation of the gallbladder)

• Blood clots in the legs and lungs [20]

The duration of hormone therapy as well as the format will vary depending on the symptoms and personal preferences, along with the risk profile of the woman [6].

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Please consult with your doctor to determine if any form of Hormone Therapy is right for you.