---
title: "What made the supporting skincare study especially credible"
description: "Learn why this skincare study is credible: double-blind, placebo-controlled design, objective dermatologist testing, and safety bloodwork on estriol."
url: "https://www.myalloy.com/knowledge-base/what-made-the-supporting-skincare-study-especially-credible"
---

# What made the supporting skincare study especially credible

> Learn why this skincare study is credible: double-blind, placebo-controlled design, objective dermatologist testing, and safety bloodwork on estriol.

## What made the supporting skincare study especially credible?

Here at Alloy, what really makes the supporting skincare study feel especially credible is the level of rigor that went into it. Most cosmetic studies rely heavily on participant opinions, but this one was designed much more like a traditional medical clinical trial.

The strongest piece is that it was **double blind and placebo controlled**, with multiple arms comparing estriol, estradiol, and a placebo. Neither the women in the study nor the dermatologist evaluating them knew which cream they were using, so bias was kept out as much as possible. An independent dermatologist investigator ran the study, and it was reviewed by an Institutional Review Board, which adds another layer of oversight.

There was also objective testing. Instead of only asking women how their skin looked or felt, trained experts assessed changes in wrinkles, elasticity, hydration, texture, and overall skin quality. Plus, bloodwork was done through LabCorp to confirm that topical estriol didn't raise systemic estrogen levels, which addresses the safety question so many people understandably have.

If you want to hear a clear breakdown of the study design and safety work, the chapter called *The Clinical Study: Design and Safety* in our YouTube conversation walks through it in an easy way. You can watch it here: [watch the chapter](https://www.youtube.com/watch?v=xHF-GD91RMc&t=778s).

And if you want to explore the details even further, the full clinical reports for both the face cream and the eye cream are available to read on our site:
[M4 Face Cream study](https://assets.ctfassets.net/md0kv0ejg0xf/4gaULAkbHbgNZtNMOgg1PI/91329de08abacf438fb83d99e756ee99/Alloy_M4_Report_063024.pdf)[M4 Eye Cream study](https://downloads.ctfassets.net/md0kv0ejg0xf/73fv7ve0a2qmQlDBUqcn8A/5b8b1232ecac36e7d7d2d9f7c74cade4/2025_Estriol_Eye_Cream_Clinical_Study_Report.pdf)

It’s a rare level of thoroughness for a skincare product, and that’s what sets it apart.

---

This answer was created using the following resources:

- [Unpacking the Latest Research on Topical Facial Estrogen | Caroline Yu & Monica Molenaar - The Clinical Study: Design and Safety](https://www.youtube.com/watch?v=xHF-GD91RMc)
- [Grown Woman Talk | Dr. Sharon Malone & Cait Kiernan - M4 Cream: Study & Results](https://www.youtube.com/watch?v=x_OyLAZeWR4)
- [The Skin Longevity Talk: Hormonal Aging, Prevention, and M4 Skincare | Dr. Aleksandra Brown - Consistency and Advanced Skincare Additions](https://www.youtube.com/watch?v=qVewt-KTeyg)
- [New Clinically-Proven, Estriol Skincare is Here! - Clinical Study Results](https://www.youtube.com/watch?v=LY879Y8_qho)
- [Why Your Skin Changes in Perimenopause and Menopause - Clinical Results of Estriol Skincare](https://www.youtube.com/watch?v=-muvssSSReM)
- [Monica Molenaar's Estriol Skincare Routine - Eye Cream Application](https://www.youtube.com/watch?v=p1S4VYyNo0E)
- [Hormones: They're More Than Just Hot Flashes! | Dr. Darwana Ratleff Todd - M4 Estriol Face Cream Study Results](https://www.youtube.com/watch?v=GQhZJVD6w2o)
- [The First and Only Eye Cream with Estriol | Skincare Innovation](https://www.myalloy.com/blog/the-first-and-only-eye-cream-with-estriol)
- [Skincare Routine | M4](https://www.myalloy.com/blog/why-estrogen-belongs-in-your-skincare-routine-and-not-just-in-your-hormone)
- [The Story Behind M4 from Alloy's Co-Founder Monica Molenaar](https://www.myalloy.com/blog/monicas-skincare-journey-from-discovery-to-results-the-story-behind-m4)
- [Topical Estrogen: Tips from Dr. Ellen Gendler](https://www.myalloy.com/blog/why-topical-estrogen-should-be-part-of-your-skincare)

---

*This is a markdown version of [https://www.myalloy.com/knowledge-base/what-made-the-supporting-skincare-study-especially-credible](https://www.myalloy.com/knowledge-base/what-made-the-supporting-skincare-study-especially-credible) for AI/LLM consumption.*