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Arimidex Timing and Dialing in E2

Been on 120mg test cyp/week. Currently my free test is 1350 and E2 is 60.2
Clinic wants me to get E2 down to around 25. My natty E2 is 30, so even this would probably be fine. Right nipple seems to be swelled so definitely having high E2 sides. Therefore, the clinic increated my dose from .25 2x/week to .50 2x/week.

My question is since I am a high E2 converted should I take my AI the day or night of injection, instead of next day as the clinic recommends? I know test cyp takes some time to raise levels but with the AI taken the same day I feel that it would keep E2 lower right off the bat.

Also, when is the best time to test new E2 levels and how long after changing dosage? I am assuming fasted the morning before injection just like T levels. Obviously I want to test when E2 is potentially the highest but am having a hard time finding a definite answer on this. E2 timing doesn’t seem to have much information online. Thanks!

You dont need an AI on TRT. Please read the forums.

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Yeah I read that many are against AIs. That T:E2 ratio is more important than actual numbers. Unfortunately I am genetically prone to gyno and would rather just avoid the issue.

How long have you been on TRT?

A little over 3 months.

I don’t mean to sound difficult but how do you know you are genetically prone to gynecomastia?

My father has mild gyno (naturally). Also, lost about 20 pounds so far on TRT but have to probably lose another realistic 40 or so. The high bodyfat is also a concern in regards to elevated E2.

I have more questions but I dont want to be disrespectful. I will trust you are predisposed. That being said I dont have an answer for AI timing. There may be others here that do. Good luck brother.

No problem and thanks. I’m not very easily offended so it really doesn’t bother me. About to head out to to train here in a few.

Your clinic is making this ten times harder than it has to be, all you need to do is lower your dosage and/or inject smaller more frequent doses as this will keep testosterone from declining while maintaining estrogen lower.

When I started injecting daily, my estrogen value for the first time was under 30, previously the EOD protocol had my E2 in the high 40’s and Total T value was the same on both protocols while the dosage was 49mg versus 80mg.


Arimidex is not the answer

No evidence of this in your numbers. Nipple sensitivity can happen just from the massive changes in hormones while you’re starting out, and 12 weeks in isn’t really that long, considering.

You current e2 is more than ok, and taking more (or any) AI isn’t going to solve your problems. If it’s a nipple issue that you can’t get over, see if they’ll give you tamoxifen to help while you’re losing weight.


Just because your father has gyno doesn’t mean you’re predisposed to it. What most people think is gyno is really just fat being stored on their chest.

Your E2 isn’t that high. I have actual gynecomastia with fibrous glandular tissue and my E2 is currently sitting at 79 without any issues. I do happen to take AI when I’m on blast, but you should try to avoid it on TRT levels like these guys are saying. Sore nipples doesn’t mean you have or are getting gyno. It’s OK to be vigilant and have AI on hand, though.

Thank you. Yes injecting twice a week seems to be what most people are doing today without the AI. This clinic seems be pretty hardcore about switching protocols, but I will ask about that on my next visit. I would like to drop the AI eventually as I felt very tired for a couple days after taking the new dose (probably crashed E2).

Thanks. That’s why I am here to find out. The simpler the cycle the better personally for me. Going to look into lowering test dose.

Thanks. My trough level day of injection E2 was 60.1 at 7 week bloodtest. Day after injection I can only imagine, probably way higher. That is why I was looking into taking AI day of injection to avoid any E2 spikes after injection. Ideally I would of liked have lost weight then got on TRT but am making good progress. I think my low test was actually making it hard to recomp. This clinic seems to like AI and I have read some nasty things about them that they are basically not safe for many reasons.

That’s not a given, though. Just to be clear. What we have are studies that are inconclusive for practical/clinical purposes. We can’t even really be probabilistic about outcomes in humans. We simply don’t have enough data (or any, really) for even that.

Are you sure you have actual gyno and not pseudo gyno from fat deposits?

I use exemestane which is another version of an AI. I take a quarter of a pill twice a week. AI’s are very strong so I would start low with a quarter of a pill of anastrozole once or twice a week max.

And I know a lot of people on here aren’t fans of AI’s but I personally have tried with and without AI and adding a little AI makes me feel better overall (better mood, libido, etc).

Your clinic would be correct. You should take it the next day once your testosterone is peaking and conversion to E2 is happening at a greater rate.

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I’m with the others. You don’t need AI. I’ve had gyno twice, had it surgically removed and thought i was also “genetically predisposed”. I was wrong. My protocol was fucked, not me. I was told to take 150mg/test weekly in a single injection. Huge peak, huge trough. It did give me gyno. 10k surgery later. All i needed to do was take more frequent smaller doses, and i could even go up and take more than 150mg/week. Throwing AI at the situation is lazy on the clinic’s part because they don’t want to get you dialed in.

I’m currently taking 160mg/week test - injected daily, 80mg/week deka - every other day, 50iu HCG Daily (I painfully atrophy without it). No AI. I’m 3 weeks into the protocol change and no “high e2” symptoms. I was on AI for nearly 3 years. There are HUGE potential health effects from being on AI for a long time. lower bone density, can kill your libido, erections etc. It did mine and that’s why i learned more about it.

Don’t mean to pile on here, but the truth needs to be said. Wish someone told me 2 years ago.
If you’re dead set on taking AI. I’d take it at the time of injection. Anastrazol (arimidex) and test cyp have a similar half life and both peak around 8 hours (i was told this), so theoretically, when you get into the high lvls and could aromitize, the AI is kicked in and preventing it.