Estriol vs. USP Estriol

Attribute	Estriol	USP Estriol
Chemical Structure	3-hydroxyestra-1,3,5(10)-triene-16α,17β-diol	Same as Estriol
Pharmacological Action	Estrogen hormone	Same as Estriol
Uses	Used in hormone replacement therapy	Same as Estriol
Regulatory Status	Not regulated by USP	Regulated by USP

Introduction

Estriol and USP Estriol are two forms of the hormone estrogen that are commonly used in hormone replacement therapy. While they have similar names, there are some key differences between the two that are important to understand when considering which one may be the best option for you.

Chemical Structure

Estriol is a naturally occurring estrogen hormone that is produced by the ovaries during pregnancy. It is a weak estrogen compared to other forms of estrogen such as estradiol. USP Estriol, on the other hand, is a synthetic form of estriol that is made in a laboratory. While both forms of estriol have the same basic chemical structure, there may be slight differences in how they are metabolized in the body.

Biological Activity

Estriol is known for its weak estrogenic activity, which makes it a popular choice for women who are looking for a milder form of estrogen therapy. USP Estriol, on the other hand, may have a slightly different biological activity due to its synthetic nature. Some studies have suggested that USP Estriol may have a stronger estrogenic effect compared to natural estriol, although more research is needed to fully understand these differences.

Regulation

Estriol is not approved by the FDA for use in hormone replacement therapy in the United States. However, some compounding pharmacies may still offer estriol as a treatment option. USP Estriol, on the other hand, is regulated by the United States Pharmacopeia (USP) and is considered a pharmaceutical-grade form of estriol. This means that USP Estriol has undergone testing to ensure its purity and potency.

Effectiveness

Estriol has been shown to be effective in relieving symptoms of menopause such as hot flashes, vaginal dryness, and mood swings. USP Estriol may also be effective in treating these symptoms, although more research is needed to determine its exact efficacy. Some women may find that one form of estriol works better for them than the other, so it may be a matter of trial and error to find the most effective treatment.

Side Effects

Estriol is generally considered to be a safe form of estrogen therapy with fewer side effects compared to other forms of estrogen. Common side effects of estriol may include breast tenderness, bloating, and headaches. USP Estriol may have similar side effects, although some women may experience more severe side effects due to its synthetic nature. It is important to discuss any potential side effects with your healthcare provider before starting estriol therapy.

Conclusion

Estriol and USP Estriol are two forms of estrogen therapy that have similar benefits but some key differences. While estriol is a natural form of estrogen that is not FDA-approved, USP Estriol is a synthetic form that is regulated by the USP. Both forms of estriol may be effective in treating symptoms of menopause, although more research is needed to fully understand their differences in biological activity. It is important to discuss the pros and cons of each form of estriol with your healthcare provider to determine which one may be the best option for you.