T Nation

How Cytomel Impacted my Total T, Estradiol, and Thyroid Hormones

So I started TRT March of this year and couldn’t be happier, a life changing experience. I am getting married in a week so on September 15th I started a mild cycle for cutting while maintaining the mass I had built over the last few years.

My cycle was as follows:

Primobolan - 160 mg EOD = 560 mg Weekly Average
Test Cyp - 100 mg EOD = 350 mg Weekly Average
Anavar - 30 mg Daily
T3 - Worked up to 100 mcg Daily
Anastrozole - .2 mg EOD with Injection = .7 mg Weekly Average
HCG - 250 IU EOD = 875 IU Weekly Average

Prior to the aforementioned cycle, I had nailed down my anastrozole dosing; .002 mg of anostrozole for every mg of test cyp would keep my estradiol per the LCMS sensative test within .5 pg/mL of 24 pg/mL. This was confirmed by changes in my weekly test cyp dosing ranging from 175 mg to 245 mg per week; .002 mg of anastrozole per 1 mg of test cyp and my estradiol levels would be 24 pg/ml.

The following blood work was performed right before starting the cycle above at 245 mg test cyp a week, .5 mg anostrozole a week, and 875 IU HCG a week.

One month in, 10/14/16, I had follow up blood work performed while on the protocol identified in the first paragraph less the HCG as I had run out. The blood work results are as follows:

Total testosterone decreased by 401 ng/dL even though I had increased my test cyp by 105 mg a week. However, free testosterone increased and estradiol plummeted to 4.2 pg/mL. I thought that maybe the lack of HCG had caused the estradiol to fall as I have read it can increase intratesticular estrogen and also may have accounted for some of the decrease in total T as my testes stopped producing any testosterone. In addition, TSH levels were down from my baseline but still within range, free T3 was up a bit.

I continued with my protocol and added HCG back into the mix right after the prior bloodwork at 875 IU per week. 11/1/16 I had additional blood work performed with the following results:

Total testosterone was still down, free testosterone saw a slight bump, and estradiol was practically unchanged. Apparently my assumption that the lack of HCG was the culprit for low estradiol was wrong. TSH continued to decrease slightly but is still within range, free T3 is up a bit more.

My guess is that the T3 has increased the rate at which I metabolize testosterone and as such there is not enough time for it to aromatize into estrogen. This also may explain the decrease in total testosterone. I wonder if there are any studies that correlate T3/T4 levels with total testosterone and estradiol at a given dose.

In addition, I have read that T3 can decrease SHBG. Unfortunately SHBG was not part of the blood work I had performed, but a decrease in SHBG could explain the increase in free testosterone while total testosterone decreased.

My questions for anyone with some insight are as follows:

  1. Is it reasonable to assume the T3 is the cause of the supression of estradiol or is it more likely the anavar and primobolan are having an impact?

  2. My TSH levels have fallen but are still within “range” and from what I can tell, my thyroids natural production has not completely stopped. As such, is it likely that my thyroid will quickly return to baseline levels after discontinuing the cytomel?

  3. I have read mixed views on tapering off T3 and my conclusion was that there doesn’t seem to be a need to taper off; tapering may delay the rebound of the thyroid. For those that share that opinion, does the fact that I still have TSH levels in range change the need to taper off?

I have now discontinued the primobolan and anavar but will continue with test cyp at 350 mg a week and T3 at 100 mcg per day until after I get back from my honeymoon; not looking for my metabolism to crash when I need it the most.

interesting. I always thought that t3 t4 increased my estrogen based on how my physique would change (softer look).

FYI, I know its almost a year later but if anyone is interested I was reviewing an excel I keep with my blood work numbers and wanted to share the post cycle results to add to the knowledge pool on this site.

After ending the aforementioned cycle, I continued to cruise on 350 mg Test Cyp / .56 mg Anastrozole per week. Administration was EOD subq injections of the Test Cyp and EOD liquid drops of the anastrozole. 2 months into the cruise my total testosterone was at 1438 ng/dL, free testosterone at 41.2 pg/mL, and estradiol at 18.8 pg/mL.

6 months after the cruise, I cycled Test Cyp at 455 mg per week, Anavar at 40 mg per day and Winstrol oral at 20 mg per day. Total test came in at 1367 ng/dL, free test at 40.3 pg/mL, and estradiol at 27.6 pg/mL.

Make whatever conclusion you want from that information. I believe the combination of increased metabolism with the likely drop in SHBG from the Anavar/Primo caused the decrease in total T.

Of those two factors, I think the SHBG played a bigger role as my free T stayed up after the cycle. If the Test was getting metabolized, I would expect free T to drop as well post cycle. I think with the EOD injections and decreased SHBG there was less bound T (total T) floating around but active (free T) stayed the same due to the frequent administration.

Hope someone finds this information useful.

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You are quite accurate with your conclusions.

Thanks, it may be common knowledge to the veterans but I figured it cant hurt to add to the conversation.