December 18 2022

An Introduction to Bio-identical Hormone Replacement – Frequently Asked Questions

Most women have some sort of idea as to what bio-identical hormone replacement entails even prior to scheduling an appointment with their doctor or handing me a prescription to be compounded. However, when I ask patients what questions I can answer, I often hear similar questions and concerns. Even years into therapy, the same questions may resurface, take on a different meaning, be more relevant to a patient. And this is great! Voicing these questions, comments, and opinions is crucial. Patients should surround themselves with healthcare providers who can answer these questions and address their concerns. 

Below you’ll find the first of three questions I’ll answer on the topic of bio-identical hormone replacement.  

Question #1 – What exactly is bio-identical hormone replacement therapy?

The best way to answer this question is with a short lesson in pharmacology. In fact, understanding this concept is crucial for understanding what the term “bio-identical” tries to convey. Here it goes! The majority of drugs are small molecules with a carefully designed structure. Whether it be mother nature herself who designed the molecule or a team of brilliant researchers, the structure is what gives the molecule its effect. Drugs with similar structures and effects are grouped together into a class. Sometimes, the slight differences between drugs within the same class have a profound influence on their potency. This is in fact the case with hormones – slight variations in structure can produce drastically different effects.     

Bio-identical simply refers to a group of hormones identical in structure to hormones produced by the body. Though technically not referring to a class of drugs, the phrase was coined as a way of distinguishing it from other forms of hormone replacement therapy available. In particular, the conventional therapy for hormone replacement at the time – conjugated equine estrogen (Premarin) and medroxyprogesterone (Provera). The idea was that using hormones with a chemical structure identical to what the body recognizes, at doses that mimic the body’s natural levels will provide a more patient-specific form of therapy, and that using hormones identical to what the body recognizes would be safer, better tolerated, and possibly more effective. In other words, if we’re trying to replenish estrogen why not use actual estrogens if they’re available? Enter the compounding pharmacist who has access to pharmaceutical-grade hormones and is trained in preparing all sorts of dosage forms with these hormones!

Bio-identical hormone replacement was thought to be an improvement upon the conventional form of therapy at the time - Premarin and Provera. As it would turn out, Premarin and Provera are not as harmless as thought. In fact, today they are NOT routinely prescribed putting bio-identical hormone therapy at the forefront of treatment options for women suffering from symptoms of hormone imbalances. To the determinant of patients, many providers group all hormones into one category and forget that not all hormones are equal in safety and effectiveness.

Bio-identical hormone replacement allows for patient-specific hormone combinations, at patient specific doses, in a dosage form that patients prefer. This personalization is what makes bioidentical hormone replacement a valuable treatment option.

Written by Angelo Maida, PharmD

Angelo Maida is a compounding pharmacist at Maida Pharmacy Compounding and Wellness. He can be reached at or at 781-643-7840

Written by:

Angelo Maida, PharmD