Alvin Pettle, M.D. – Toronto Bioidentical Doctor

Natural bio-identical hormone therapy is the present and growing future of hormone replacement therapy. Patients and doctors do not have to wait 50 years for medicine to change and catch up. Physicians throughout the world are now beginning to realize that you cannot fool mother nature, and if you try to do so, there are frequently negative consequences. Use of synthetic hormones has now been shown by many studies and by much experience to have adverse side effects, leading to dangerous complications such as breast cancer, heart stress and other clinical problems.

The Women’s Health Study of 2002 has shown that use of synthetic hormones is not the healthiest way to replace women’s hormones. Human female bodies do need natural bio-identical hormones, which can be used for optimal health. The lock and key effect of natural treatment works perfectly with the body and within a 12 hour period, 50% of the hormone has been dissipated naturally by the body.

Natural bio-identical hormone treatment therefore appears to me to be the desirable future of hormone replacement therapy.

How can bio-identical hormones help fight the symptoms of aging?

Bio-identical natural hormones are anti-inflammatory and therefore anti-aging by their nature of action. Bio-identical hormones fit into receptor sites like a lock and key mechanism. The effect of the hormones is specific to the dose required by the bio-identical hormones. In nature, more is not necessarily better. In fact, even natural hormones if prescribed in too high a dosage can cause adverse side effects, such as sedation.

In our clinic, we do carefully monitor most hormone levels with blood tests, although they are not as reliable as saliva tests. Unfortunately, saliva tests are not at this time covered by OHIP. It is the free hormone level that is inside the body which is measured by the more accurate and useful saliva test rather than the bound hormone level measured by blood tests. Test results from blood can change considerably from hour to hour, whereas saliva test results are more consistently stable over time, and therefore more reliable indicators. We do use blood tests to measure free testosterone levels, for which they are quite accurate. We also record symptoms reported by patients as complementary indicators to assess the status of each patient.

Will bio-identical hormones help with hot flashes, sleepless nights and memory problems?

Natural progesterone is very effective in the treatment of hot flashes. We find that half of our patients with hot flashes respond positively to progesterone treatment alone, and do not require any estrogen, even bio-identical estrogen. The other half do receive relief with further supplementation of natural transdermal estrogen. Some time ago, I would have prescribed oral estrogen in the bio-identical form, but I now believe it is preferable to advise transdermal estrogen. If a patient swallows estrogen, the estrogen must be synthesized by the liver as a first pass and that can have adverse consequences such as increased coagulation of the blood and increased blood pressure and adverse changes in the CRP reading. Oral estrogen also reduces efficiency of the thyroid as it produces an increased level of thyroid bonding globulin which in turn often results in patients having subclinical hypothryoid and resulting weight gains and retention.

Bio-identical hormones especially help insomnia. The progesterone transdermal cream used in the evening has a mild sedative effect, but the oral form of progesterone passes through the liver and has an even greater degree of sedation. Oral progesterone is therefore used specifically as a treatment for insomnia and is prescribed to be used at night before sleep for this reason. Natural transdermal progesterone, absorbed through the skin only, can be used both morning and evening without any prohibitive sedative effects.

We have found that patients report improved memory with the use of bio-identical hormones as lubrication of brain synapses seems to allow quicker cognition, alleviating this common symptom of hormone balance occurring with menopause and simple aging.


A gradual process that happens when a woman’s ovaries make less estrogen and progesterone and her lifetime supply of eggs is depleted. A woman is considered to have reached menopause when she hasn’t menstruated for 12 months. Natural menopause typically occurs between ages 41-59. Symptoms of Menopause Include: Hot flashes, flushes, night sweats and/or cold flashes, clammy feeling, irritability, mood swings, sudden tears, trouble sleeping through the night, loss of libido, crashing fatigue, anxiety, depression and more.


The period of transition to natural menopause during which the body undergoes endocrinologic and biologic changes resulting from declining ovarian hormone production; Symptoms of perimenopause can include irregular menstrual periods, hot flashes, vaginal dryness, insomnia, and mood swings. Perimenopause can last over six years (four years is average) and usually ends after twelve months of amenorrhea.

More and more physicians are now beginning to research, assimilate and practice natural bio-identical hormone therapy. I believe that within the next 25 years this will be the ideal medical standard for hormone replacement therapy and will be taught to new doctors in our medical schools. Current graduates of medical schools are not being given the current information and updates on this emerging hormone replacement therapy alternative to synthetic treatment. Some doctors are still confusing natural progesterone with synthetic progesterone.

Questions? Please call Toronto Bioidentical Doctor, Alvin Pettle, M.D. directly at 800-775-4902 Ext. 423 to discuss your health concerns and schedule a Bioidentical Hormones Replacement Therapy appointment.