I've been asked a few times about topical Estrogen cream for hair loss prevention.
BiEstro-Care cream and Estrogel in particular.
BiEstro-Care is a is a combination of 1 mg of natural Estriol USP and 0.25 mg of natural Estradiol USP per pump.
I've also tried their Estradiol-only topical, Estradiol Care.
Each full press of the pump provides approximately 0.1 mg of natural Estradiol USP in that topical preparation.
I've also tried pharma grade Estrogel, which is an FDA-approved, bioidentical 17β-estradiol transdermal gel at 0.06% w/w strength.
The hypothesis in the community is that the topical Estrogen cream will bind to Estrogen receptors in the scalp and produce a more conducive environment for hair loss prevention without going systemic as it remains localized on the scalp.
Think of it like topical Minoxidil vs oral Minoxidil.
The topical version doesn't go systemic to the same degree, and still exerts significant pro-circulatory effects.
Localized Estrogen Receptor Activation
On paper, it is easy to extrapolate the potential benefit of being able to topically apply Estradiol or Estriol and get some sort of localized binding with a relative lack of systemic estrogenic activity.
However, it just doesn't seem to work like that in practical application.
I noticed absolutely no difference on my hair growth or hair loss prevention, whatsoever.
It's also not very predictable in terms of pharmacokinetics in the body going through the scalp.
Does Topical Estrogen Cream Promote Hair Growth
I can confirm that topical Estrogen cream on the scalp is very poorly absorbed and has minimal impact on hair growth, or the progression of androgenic alopecia.
I checked my blood work via a high sensitivity assay (LC/MS-MS) and I was actually shocked at how poor the systemic absorption was through the scalp.
If your goal is to try and maintain physiologic amount of systemic estrogen fulfilled via transdermal administration of topical Estrogen cream, you will likely be unsuccessful.
The absorption through the scalp is extremely poor.
I was drenching my head in this stuff to really test it out.
Even when I had several milligrams of Estradiol cream on my head per day, my E2 levels were low.
The hypothesized topical localized effect on Estrogen receptors also doesn't seem to play out as we thought it may.
I noticed no additional growth out of it, and feel that it is an overhyped growth agonist that may just do more harm than good.
The most notable biomarker that changes with topical Estrogen cream on the scalp is Estrone, which goes through the roof.
To date, I have never seen anyone actually get good results from topical E2 to begin with, and any cases of regrowth with its use were in cases where other therapies were used in conjunction with it.
Anybody who deploys this as a form of monotherapy to prevent hair loss will be disappointed with their lack of results in my opinion.
At the end of the day, preventing hair loss at the root of the issue just boils down to managing your overall systemic androgenicity relative to systemic estrogen levels.
My Verdict On Its Efficacy For Hair Loss Prevention
As a growth promoting agent (what it would mainly excel at), I feel that is probably not even worth exploring to be honest.
It certainly doesn't seem to exert any antiandrogen-like effects at the androgen receptor either that would justify its use in my opinion.