As I understand it, “functional medicine” includes:
1] EDUCATED PATIENTS: The high school curriculum includes hormonal, metabolic and microbiome health as a formal subject, so that all understand health maintainance.
2] HEALTH CARE PRACTITIONER: The healthcare professional is an MD, trained in the application of the principles of standard medicine and in the art of metabolic and hormonal maintenance. *

3] FIRST ASSESSMENT: Preferably, the first assessment should be at age 15; it can be done earlier if puberty begins before age 11 or if the child is obese, anorexic, depressed or subject to PTSD for any reason.
The patient’s physical, psychological, metabolic and hormonal status is assessed by history, physical examination and standard “checkup” tests, plus testing for neurosteroid hormone balance, microbiome status, adrenal function, vitamin D level, toxic load, thyroid function (including T3 and rT3, so as to exclude functional hypothyroidism) and other investigations as may seem necessary. **
4] INITIAL CARE: Investigation results are compared with those expected of a healthy, functionally euthyroid 15-25 year old of the same gender and the physician endeavours to correct such metabolic, or hormonal, deviations as may be discovered so as to maintain metabolic and hormonal health at youthful (age 15-25 years) levels ***.
5] HEALTH SURVEILLANCE: If all parameters are within normal limits, or when aberrations have been corrected, the assessment is repeated every five years.
Routine immunisations and “preventions” such as PAP smears, mammography, colon cancer tests, PSA etc. are provided according to accepted routine.
6] ONGOING CARE: Following each 5-yearly reassessment, deviation from normal hormonal, microbiome and metabolic balance is regarded as prodromal to illness and is managed proactively by supplementation of hormones, minerals, vitamins, antioxidants, probiotics etc, ad hoc.
7] INCIDENTAL ILLNESS: Illness presenting in spite of functional maintenance is investigated and treated as it currently is, without discontinuing supplementation.
8] ELDERCARE: At menopause or symptomatic andropause, hormone restoration tailored to the individual is provided as it is currently, utilising bioidentical preparations.

* Currently, functional, antiaging and hormone restoration medicine associations, mostly in the USA, offer training courses which culminate in formal examinations and granting of certificates of competence.
These organisations do accept non-medical candidates.
My certification acronym is ABAARM, from the American Academy for Aging and Metabolic Medicine, which is owned and operated by the TARSUS group.

** “Hormone balance tests”, done on both men and women, include DHEA, Testosterone, IGF-1 ****, Oestradiol, Progesterone, Thyroid function (TSH, T4, T3 and reverse T3), Cortisol and Allopregnanolone (when it becomes available).

*** 1] Normal hormone production rates are not a given: children subject to PTSD, severe illness, trauma or major surgery often fail to achieve normal rates in early adulthood and for example, 60-y-o DHEA levels can be found in many “20-somethings”.
2] At age 26 we all, both men and women, begin to reduce our neurosteroid hormone production, from whatever level we acheive at 25, by 1-2% per annum. Thyroid hormone, Growth hormone, Melatonin etc also decline.
3] Because of this “slide”, we should reassess all our “normal” test ranges, accepting only healthy, functionally euthyroid individuals between the ages of 20 and 25 years.
4] “Age-adjusted normal” is a misnomer: a better term would be “Age-related deficiency”.
**** 5] IGF-1 is a marker for human growth hormone (HGH), which promotes growth and maturation in youth and functions as an “anabolic” (muscle and organ maintenance) hormone throughout life.
As with most of the other hormones, HGH production falls as we age and HGH deficiency is one of the factors which lead to loss of muscle mass and progressive frailty as we age.
Please see my blog regarding HGH.

Keeping the internal millieu of the human body at youthful levels assists maintenance and repair processes, including apoptosis of new cancer cells, repair of brain tissue, optimisation of glucose and cholesterol management, fat control, (heart and skeletal) muscle maintenance, cognition and just about everything else.
Therefore hormone balance should be maintained via supplementation of deficient hormones or hormone precursors, along with vitamin and mineral balance, whether the individual remains healthy or develops some pathology, so as to ensure that the body’s repair tools are always available.

I am a Toronto-trained Urologist. I practiced in downtown Toronto, from 1977 to 1997, when I went to Saudi Arabia as chief of Urology at the Armed Forces (teaching) hospital in Tabuk. Returning to Toronto in Y2000, I switched to family practice. In 2007, began to prescribe Hormone Restoration Therapy and in 2012, I became a member of the American Academy of Antiaging Medicine [A4M]. I successfully wrote the A4M's written examination in December, 2013 and In May, 2016 I passed the oral examination, for accreditation as a BHRT consultant. In 2014 I began BHRT practice in Collingwood, Ontario and in January, 2017, joined the Stone Tree Naturopathic Clinic. Now I am 82 and have retired, but it seems wasteful to jettison my learning and experience: the medical establishment knows nothing of BHRT / Functonal medicine and I feel obliged to offer my knowledge in the interest of those who are willing to think outside the box. MY QUALIFICATIONS: MB, BS, (from UWI), 1964. LMCC 1969. FRCSC (Urology), 1974. ECFMG 1984. Florida license 1998 [inactive], ABAARM Certification [A4M], 2016. I am a Member of CSAMM [the Canadian Society for Aging and Metabolic Medicine], the OMA&CMA, SUSO, CUA, RCP&S/C. PRACTICE TO DATE: Consultation in Functional Medicine, including assessment of Chronic Fatigue Syndrome, Fibromyalgia, Andropause, Menopause, Teenage and Postpartum Depression/Panic Attacks, Thyroid Hormone malfunction, Infertility, Sexual Dysfunction and “the Undiagnosable”. ALL ARE WELCOME to read, comment or question!