Medically reviewed by: Dr. Robert D. Rubin, MD. Last reviewed November 2026
While synthetic or animal-derived Hormone Replacement Therapy (HRT) has held its position as the medical industry standard for decades, patients are increasingly gravitating toward bioidentical hormone replacement therapy (BHRT) options due to their chemical similarity to human hormones. The desire for customized dosing plans and an ever-increasing cultural shift toward holistic wellness are also driving this trend. In this blog, we examine the differences between HRT and BHRT, their history, how the hormones are sourced and produced, and how they compare in terms of side effects, delivery methods and tolerability.
While synthetic or animal-derived Hormone Replacement Therapy (HRT) has held its position as the medical industry standard for decades, patients are increasingly gravitating toward bioidentical hormone replacement therapy (BHRT) options due to their chemical similarity to human hormones.1 The desire for customized dosing plans and an ever-increasing cultural shift toward holistic wellness are also driving this trend.
Hormone Replacement Therapy is a medical treatment that adds or replaces hormones when the body stops producing enough of them. Both Bioidentical Hormone Replacement Therapy (BHRT) and synthetic or animal-derived Hormone Replacement Therapy (HRT) are most commonly used to relieve symptoms like bone loss, hot flashes and night sweats caused by declining or fluctuating hormone levels during perimenopause and menopause - or andropause in men.
Both BHRT and conventional HRT can be delivered via pills, patches, gels, creams or subcutaneous pellets. Clinical data on subcutaneous pellet therapy (available as either BHRT or HRT) shows strong symptom relief.
HRT, which uses either synthetic and animal-derived hormones, has been in mass medical production and practice longer than the modern version of bioidentical hormones we call BHRT. Both trace their origins to the 1930s, but bioidentical hormones were harder to deliver effectively back then. Early on, the use of bioidentical hormones often involved painful injections.
Synthetic and equine-derived HRT, on the other hand, quickly catapulted to dominance in the industry with mass-marketed preparations that became widely prescribed and standard in medical practice.
BHRT did not gain widespread mainstream popularity until much later, largely via alternative and anti-aging medicine in the late 1990s and 2000s after micronization and new combination formulations (like FDA-approved BHRT options in later years) began to emerge.
Bioidentical Hormone Replacement Therapy uses hormones that have precisely the same molecular and chemical structure as the hormones naturally produced inside the human body (e.g., estrogen, progesterone and testosterone).
Where bioidentical hormones are sourced: Many bioidentical hormones are initially derived from plant sources like soybeans or wild yams and then processed in a laboratory.
FDA-Approved vs. Compounded: Some bioidentical hormones are mass-produced and approved by the FDA, such as micronized progesterone or some estradiol patches and pills. Others are compounded by special pharmacies to fit an individual prescription and are not monitored by the FDA.
Traditional HRT typically uses synthetic or animal-derived hormones (such as conjugated equine estrogens or synthetic progestins like medroxyprogesterone acetate), whereas BHRT uses plant-derived hormones that share an identical chemical and molecular structure to the hormones naturally produced by the human body (such as estradiol, micronized progesterone and testosterone).
Some women are sensitive to synthetic progestins: Patients who experience mood swings, bloating, or adverse side effects from synthetic progestogen drugs often tolerate micronized progesterone (a body-identical form used in BHRT) much better.
BHRT methods are preferred by patients concerned about blood clots or cardiovascular risks. Transdermal bioidentical estradiol and micronized progesterone have a more neutral effect on blood coagulation, carrying a lower risk of stroke and blood clots synthetic options.
Some patients report higher satisfaction or better symptom control using transdermal patches, gels, or specific prescribed bioidentical formulations that match human molecular structure.
Dr. Rubin's program begins with a comprehensive functional evaluation before recommending any medication. That evaluation looks at metabolic markers, hormone levels, body composition, and lifestyle factors that influence how well each drug works for a given patient. The goal is to match the right tool to the individual's physiology.
At Improving Your Health, located in Naples and Tampa, we take a Functional Medicine approach to balancing and replacing hormones that are designed to correct underlying cause(s) of chronic conditions or symptoms. Discover the difference BHRT can make in your overall health and wellbeing.
For patients in Tampa, learn more about bioidentical hormone replacement therapy in Tampa. If you are in Naples, explore our Naples BHRT Clinic in that area.
Dr. Robert D. Rubin specializes in functional medicine, bioidentical hormones, weight loss therapy, and sexual health treatments. Dr. Rubin is a widely respected functional medicine practitioner in Florida with offices in Naples and Tampa, as well as a convenient telemedicine treatment program. He has extensive experience treating patients who are struggling with longevity and health concerns.
As an Advanced Fellow in the American Academy of Anti-Aging Medicine, who is also AMA Board Certified in Internal Medicine and Geriatrics Medicine, Dr. Rubin is a dedicated medical professional with an exceptional track record. He spent the first 25 years of his medical career working in internal and geriatric medicine, successfully becoming one of Palm Beach County’s top-rated physicians. For four years, Castle Connolly Medical, Ltd. recognized him as one of the “Top Doctors” in South Florida.
After further specialized training, he shifted his practice to a functional medicine approach to better serve the needs of his patients. Over the last 15 years, Dr. Rubin has honed his focus, creating a practice rooted in evidence-based healthcare that addresses the root causes of your symptoms.
Combining this with his expertise in Internal Medicine and Geriatrics, he provides a comprehensive approach to your health. Dr. Rubin always takes an individualized approach to treatment, recognizing that each patient has a different medical history, symptoms, and underlying issues. Listening attentively to your concerns, Dr. Rubin personalizes a treatment protocol to meet your needs, guiding you confidently on your lifelong health journey.
To balance or replace essential hormones and revolutionize your health and wellness with BHRT, book online or call either of our offices today for in-person or telemedicine options.
Tampa Clinic: (813) 499-1440
Naples Clinic: (239) 977-9220
Stuenkel CA, Manson JE. Compounded Bioidentical Hormone Therapy: The National Academies Weigh In. JAMA Intern Med. 2021;181(3):370–371. doi:10.1001/jamainternmed.2020.7232↩︎
