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How Long After Starting TRT Does Natural Production Shut Down?

I was wondering how long it would take for the body to shut down its natural production of testosterone after starting TRT. Does anybody know? Does it depend on the dose?

I noticed slight testicular atrophy and my FSH and LH were non-existent at the 6-8 week mark. I can’t give you an exact timeline, but you can expect it to be gone around then, regardless of dose.

Did you get FSH/LH tested prior to the 6-8 week mark and if so, were they close to how they were prior to starting TRT?

I seem to be on too low of a dose. I noticed significant improvements starting at the end of week 1 of treatment, but now in week 4 I am back to baseline and my numbers are as well. So I wonder if my own production stopped pretty much around that time. That would mean that while the external testosterone supplemented my own production things improved but then I shut down and the dose of external testosterone is not sufficient to do more than just replacing my low levels.

Definitely possible you started to shut down after a week. I didn’t get my numbers checked before 6 weeks.

What is your protocol?

I am on a medium dose (2 clicks) of testosterone gel (1.62%). I was on Clomid for over a year but it didn’t resolve all my symptoms. My endocrinologist suggested to try a different options but wanted to go the gel route first to see if I even feel a difference compared to Clomid. I did, starting near the end of week 1 until around week 3, then everything went back to baseline again, symptoms as well as numbers. I am now pretty much where I was before Clomid or testosterone. I am assuming he may raise the dosage after he sees my numbers and hearing my observations. My goal is to then switch to injections at one point in the near future.
I just want to make sure that my theory sounds plausible that I felt symptom relief in week 2 and 3 and then went back to where I were before treatment. I want to tell him that I think I felt good at first because I had both, my own and the external testosterone in my blood and that things changed after my own production shut down. So I am trying to find information on when the shutdown typically occurs after starting TRT.

Yes, it’s pretty common to feel better then have it drop off after a week or two if under dosed.


I was taking 200mg a week split into two doses and after my first 6 weeks, my total testosterone was 1720. Then 6 months later on the same dose my total T was in the 1200’s. That makes me think it took weeks/months for my natural production to go down.

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I don’t have any data here, so consider this speculation. I would expect your production to shut down all but immediately. Within days. Why? The body’s feedback system. It “wants” to be at a certain level. Depending on the reason for your low T, either the signals to produce aren’t being sent / received or your testes aren’t up to the task…either way, your body naturally tries to maintain a certain level (subject to diurnal cycles).

When your T is above that level, the signals will not be sent, and your testes will furlough the factory. It’s not gonna take weeks/months to say “Well, there’s plenty in the bloodstream, you don’t need my $.02 anymore!”

In my opinion.