17 Alpha Estradiol: Use and Dosing Experiences

I’ve been in contact with the authors of this new paper below that just came out, and I’m thinking it might be valuable to talk with them and get some questions about this paper answered. If you’ve had a chance to review the paper and have some questions - please post them here in this thread.

Here is the full Macaque estradiol paper:

Assessing tolerability and physiological responses to 17α-estradiol administration in male rhesus macaques

Stout et al. 2023 (17a Macaques).pdf (915.8 KB)



6 march I got my blood test and on 8 march I started taking 2mg daily. After about a week I had hot feet at night, I normally only get this when it’s very hot, now it’s the end of winter here… Luckily only 1 night. I suspect this was an estrogen effect.

I will get another blood test 9 may because I have to go to my TRT doctor 19 may. I will post updates when I experience something.


Any updates on this?

What was your daily dose of 17a-estradiol and your weight/height?

(I started 17a-estradiol 10 days ago, 30mcg daily with Tanath’s formula applied throughout the day)

I’ll be excited to update the forum in 3 months with my bloodwork. Estrogen levels before 17a: 92.5pmol/l - 25.2ng/dl. not a sensitive test

I sadly didn’t measure IGF1 and GH.


My first test results experimenting with 17a-E2 from Pantostin.

Background : I was already taking Rapacan 20 mg (no GFJ) every 2 weeks (3/3, 3/27 etc). I am 63 years old & diabetic on Metformin (500mg 2x/day), Mounjaro (5mg/week) and Empagliflozin (10mg/day), and Dutasteride (0.5mg/month, DHT suppressor for enlarged prostate).

  1. Pre-E2 on 3/13 : Total Testosterone = 579 ng/dL (Free = 6.7ng/dL), E2= 26.9pg/ml, E2(LC/MS/MS)= 26pg/ml, DHT = 18ng/dL, IGF1= 138 ng/mL, FSH = 51.5 mIU/mL, LH = 16.4 mIU/mL.

Note that my Testosterone has been in the low normal range of 290-300 ng/dL for the last several years, so my starting Rapamycin 2 months previously is my only explanation for the suddenly higher Testosterone values and the very high FSH,LH values.

I started using 1mL of Pantostin 2x/day on my forearms (Using a mix of 2 parts Pantostin with 1 part transcutol), with an expected dosage for 17A-E2 of 0.50 mg/day with expected absorption of 50ug/day.

  1. First retest on 3/24 : Total Testosterone = 614 ng/dL (Free= 10.3ng/dL), E2 = 23.6 pg/mL, E2(LC/MS/MS)=Sample Rejected(Unknown interfering substance), IGF1= 150 ng/mL, FSH = 55.3 mIU/mL, Insulin= 7.9 mIU/mL, CRP(hs)= 1.68 mg/L.

This is not what I was hoping for : regular E2 (according to Baldi that should include both 17b-E2 + 17a-E2) actually dropped! Not sure why the E2(LC/MS/MS high sensitivity) test failed : perhaps Lapcorp sees the line on the chromatograph for 17a-E2 (very near the 17b-E2 line) as an interfering substance ?

I will increase the amount of transcutol to 1 part for every 1 part Pantostin to maximize absorption (so 1mL Pantostin + 1 ml Trancutol applied 2x/day) and retest on April 10, to see if I can at least observe the increase in total E2 observed by Baldi. If the E2(LC/MS/MS) is rejected again I will retry next time with Quest instead of Labcorp.


There is an article Falsely Elevated Steroid Hormones about labs reporting false positive highs for Estradiol which can result in unnecessary treatment for breast or ovarian cancer, including surgery… As a result labs err on the side of not reporting high E2 results without retesting, and then only report results if the retest confirms the original value. My result had a footnote stating the LC/MS/MS test was repeated but failed again. The article states that the superior LC/MS/MS method don’t normally suffer from the problem with interference, so it is not clear why my test is only having problems with the LC/MS/MS E2 test.

  1. Second retest on 4/10 : Total Testosterone= 409 ng/dL (Free= 1.2ng/dL), E2= 26.1 pg/mL, E2(LC/MS/MS) = 54 pg/mL (reported 17 days after blood draw and Labcorp has refused to post the result on the patient portal like they normally do!), Insulin= 7.1 mIU/mL, CRP(hs)= 1.26 mg/L (IGF1, DHT & FSH tests were accidentally not performed by Labcorp, they said not enough blood was drawn and I could redo them at no charge). So good news is the E2(LC/MS/MS) test was finally reported by Labcorp and seems to reflect the 17a-E2 + 17b-E2 and is already at the upper end of range (8-58) for post-menopausal women: the upper end presumably reflects women on HRT.

I will double the Pantostin application to 4x per day, estimated absorption of 100ug/day and retest on May 15 (using Quest for the E2(LC/MS/MS) test).


Bryan Johnson is finally talking about his 17aE use:


Your experiment is very informative, I have bought Pantostin but have thinning hair so will probably use it for that too, I have ordered some transcutal. My question to you is: do you know the composition of the Pantostin - in particular, I want to know how many mg of 17 Alpha Estradiol are in a set amount (e.g. 1ml or 30ml)? What is the absorption rate? So for instance, if there is 10mg of 17 Alpha Estradiol per 30ml of Pantostin and 10% is absorbed, then an effective dose of 1mg would be achieved. You seem to have done the research, so thank you. I would be grateful if you would share your knowledge.

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1ml of Pantostin has 0.25mg of 17alpha-E2 and 10% of that is expected to be absorbed through the skin if you apply it with transcutol. I am currently using a 50:50 mix, and apply 2ml of this mix 4x/day which should include 1mg of 17alpha-E2 and expect around 0.10 mg per day to be absorbed. That is the upper end of the range for female HRT (for 17beta-E2), so I would be cautious about going any higher than that without close medical monitoring.


Has the price of 17 Alpha Estradiol decreased this year? Chinese suppliers are currently offering it at about 5 times cheaper than last year’s price. The price I found on the Chinese supplier ‘Aladdin’ is $314 USD for 5g.

I doubt it - its only being sold as a hair growth topical formulation in Europe right now and its not particularly effective in that role from the research I’ve seen. And I still think the China option is a poor one as quality is likely to be an issue.


Hello RapAdmin, You said it’s not particularly effective. Can you share the most recent paper regarding this conclusion? I’ve been busy lately and haven’t been keeping up with related papers.

The hair research with 17alpha estradiol was done a long time ago, and the products that resulted from it started being sold many years ago. Nothing new has come out on 17alpha estradiol since the NIA ITP research.


I saw Bryan Johnson say that he’s been using alpha estradiol lately. I’m not sure if I remember correctly?

Yes - his doctor, Oliver Zolman, helped him get it from the sounds of things (and they mention that it was very hard even for them to get). They made a topical cream from the 17alpha estradiol powder - and that is what he’s using.

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Yes. 4mg wk, transdermal, see post from RapAdmin above:

I think he also discusses it in one of the videos on the blueprint web page


Sorry for the late update, been very busy with work and training;
my results from 6 march: Estrogen levels 32.9ng/L. 3 weeks later I got it tested again ( so after taking 2mg/ day of 17-a-estradiol for 3 weeks) it had risen to 48,8 ng/L. I got it tested because I experienced acne on my back and shoulders. I stopped taking 17-a-e. and got my blood tested again on 2 may, levels were still 47,9 ng/L. (reference range max 43,2 ng/L). Acne gradually went away after discontinuing the 17-a-e. , were normal 1 month after discontinuing. I think that because I am already taking testosteron, I am more sensitive to acne and starting with a high dose of 2mg/ day also isn’t a good strategy. I am going to do another experiment in october, most probably with a weekly dose of 4 mg transdermal inspired by the Bryan Johnson blueprint dosage. Any thoughts / suggestions are welcome!

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An update today from another user of 17-alpha estradiol (topical):


I think if you’re not on TRT, you get a suppression of your testosteron and as a consequence a loss of libido

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there’s another comment on this threat saying it should increase testostrone, because of the hpa axis.

it is hard to gauge whether it increases libido or decreases it based on this thread.


If it acts as a 5ari it can indirectly increase estradiol which could lead to a lower libido.

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Bryan Johnson’s latest report on his use:

from here: https://twitter.com/bryan_johnson/status/1696944026015117793?s=20