---
title: "Estradiol vs Estriol in Topical Products"
description: "Estradiol vs estriol in topical products: learn the key differences, why estriol is often chosen for skin, and how each estrogen works."
url: "https://www.myalloy.com/knowledge-base/estradiol-vs-estriol-in-topical-products"
---

# Estradiol vs Estriol in Topical Products

> Estradiol vs estriol in topical products: learn the key differences, why estriol is often chosen for skin, and how each estrogen works.

## What is the difference between estradiol and estriol in topical products, and why is estriol often chosen?

### The short version

Estradiol and estriol are both forms of estrogen, but estradiol is the stronger one. It’s the main estrogen tied to reproductive function, and in topical medicine it’s often used when you want a stronger local effect, like our vaginal estradiol cream for dryness, itching, urinary symptoms, and painful sex.

Estriol is less potent than estradiol, but it still works well on skin. That’s why it’s often chosen in topical skincare. In low doses, it helps support collagen, moisture, skin thickness, and elasticity, while staying a lower-strength option overall. It’s also much weaker in stimulating breast tissue and uterine lining tissue, which is part of why, here at Alloy, we chose estriol for our M4 skincare line. Our clinical testing found no change in systemic estrogen levels with topical estriol.

If you want a deeper explanation, this [article on estriol and skin health](https://www.myalloy.com/blog/what-is-estriol-and-what-is-estrogens-role-in-skin-health) is useful, and this [video chapter on why estriol is used for skin](https://www.youtube.com/watch?v=sW48U6HSkcc&t=309s) explains the thinking clearly. You can also see how we use it in [M4 skincare](https://www.myalloy.com/solutions/m4?utm_source=blog&utm_medium=blog&utm_campaign=m4&utm_term=blog).

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This answer was created using the following resources:

- [Debunking Myths About Topical Estrogen | Dr. Ellen Gendler & Dr. Corinne Menn](https://www.youtube.com/watch?v=ZPxBSmOkxNI)
- [Topical Estrogen's Role in Healthy, Radiant Skin | Dr. Ellen Gendler & Dr. Corinne Menn - Estradiol vs. Estriol](https://www.youtube.com/watch?v=kOzPrwnwsFA)
- [Dr. Ellen Gendler on the Role of Estrogen in Skincare | Dr. Ellen Gendler & Dr. Corinne Menn - Estradiol vs. Estriol](https://www.youtube.com/watch?v=jtTfgMJbQVU)
- [Skin Deep with Dr. Menn: Let's Talk Skincare & Estrogen | Dr. Corinne Menn - Why Estriol for Skin](https://www.youtube.com/watch?v=sW48U6HSkcc)
- [What is estrogen's role in health?](https://www.myalloy.com/blog/what-is-estriol-and-what-is-estrogens-role-in-skin-health)
- [Topical Estrogen: Tips from Dr. Ellen Gendler](https://www.myalloy.com/blog/why-topical-estrogen-should-be-part-of-your-skincare)

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*This is a markdown version of [https://www.myalloy.com/knowledge-base/estradiol-vs-estriol-in-topical-products](https://www.myalloy.com/knowledge-base/estradiol-vs-estriol-in-topical-products) for AI/LLM consumption.*