T Nation

On TRT, Low Progesterone, Low Libido



I would really appreciate some help if anyone could give it.

Just to give some quick info:

  • 22 y/o
  • Been on trt for a year and it resolved the issues that I was having to a great extent (low libido, constant tiredness, brain fog, generally poor sense of wellbeing).
  • My dosing protocol is 150mg Test Cyp per week (injections twice per week), 0.25mg Adex EOD and 500 IU HCG twice per week
  • I chose to run trenbolone acetate at 275mg/wk for 2 weeks in order to gauge side effects as I had planned to run it in the future (I have aspirations of making something of myself in the fitness industry). The tren seemed legitimate as I experienced the usual side effects.
  • I ran Cabergoline at 0.25mg E3D.
  • Before the tren my libido was great and when I started, it practically disappeared.
  • It has now been over 2 months since I discontinued the trenbolone and my libido has not greatly improved.
  • I took the cabergoline for about one month after I finished the tren as I believed my low libido was caused by high prolactin.

Here is some bloodwork that was taken 1 month after the tren

Thyroid Function
FREE T3 7.5 pmol/L 3.10 - 6.80
FREE THYROXINE 20.4 pmol/L 12.00 - 22.00

TESTOSTERONE 69.9 nmol/L 7.60 - 31.40
17-BETA OESTRADIOL 45.2 pmol/L 0.00 - 191.99
SEX HORMONE BINDING GLOB 39.6 nmol/L 16.00 - 55.00
PROLACTIN 21.5 mIU/L 86.00 - 324.00

After receiving this bloodwork it seemed that the problem was in fact low prolactin / low estrogen so I stopped the caber and the ai, however this did little to help.

I adjusted my Adex dosage, waited another month and have just received my latest test results:

PROGESTERONE 0.16 nmol/L 0.70 - 4.30
PROLACTIN 268.00 mIU/L 86.00 - 324.00
17-BETA OESTRADIOL 74.5 pmol/L 0.00 - 191.99

The prolactin and estrogen are now almost perfect so it seems that progesterone is the problem. This is where I was hoping for some help as I don’t know much about progesterone and it seems hard to find reliable information about it elsewhere.

Here are some questions I have:

  • Is the low progesterone likely to be the cause of my low libido and other symptoms? (I have also been experiencing some mild depression and insomnia).
  • What is the likely cause of my low progesterone? I also regularly take caffeine preworkouts and thought there may be a link to adrenal fatigue.
  • What is the best way to increase progesterone? I have heard pregnenolone can be taken, is this advised?
  • Any other advice welcome.

Many thanks for reading.


You’re hyperthyroid, fT3 is above ranges, never seen fT4 quite that high. You must have suffered high SHBG before TRT. I wonder if those steroids made you hyperthyroid…?


Yes I noticed they were at the top end of the range but I didn’t think they were high enough to merit that response. Yes my SHBG was slightly above the range before TRT. My last thyroid test in April of last year showed T3 at 6 pmol/L, T4 at 19.7 pmol/L and TSH at 1.7 mIU/L. I thought that the raised levels may have been due to low prolactin as I read somewhere that it could elevate them. Is hyperthyroidism linked to poor libido?

I find it hard to believe that the trenbolone could have caused it because it was such a low dose and was run for less than 2 weeks but perhaps so.


TSH should be closer to 1.0
fT3, fT4 should be near mid-range or a bit higher.
fT3, fT4 are stating that you are hyper
TSH says you are hypo
Suspect that you have elevated rT3 blocking fT3. Check your oral body temperatures, see below, to evaluate your overall thyroid function and post temperatures. Also discuss your history of using iodized salt. If low, see references to rT3, stress, adrenal fatigue and Wilson’s book in the thyroid basics sticky.

Thyroid lab ranges are stupid. Do not expect your doctor to understand any of that.

You need to be near E2=22pg/ml and your E2=45.2 is horrible and also a libido killer that probably makes you moody and intolerant.

Most guys need 1mg anastrozole for every 100mg T ester. We can also calculate a new dose from labs if your dosing prior to lab was consistent. New dose = old dose x 74.5/80 where the target is 22pg/ml or 80 pmol/L. So your adex dose for the 2nd set of labs is fine, IF you were dosing consistently for 8 days prior to your labs.

Thyroid problems easily kill libido.

You need to test AM Cortisol, at 8AM or 1 hour after waking up to see if low progesterone might be causing lower progesterone–>cortisol in the adrenals. If you have adrenal fatigue, multiple adrenal hormones affected. DHEA is also an adrenal hormone, but DHEA it at a lifetime high at your age. The lab test would be DHEA-S, not DHEA.

Were prolactin, LH and FSH tested before you started TRT. Malpractice otherwise. Post these.

You can find “KAL” brand progesterone cream at Amazon.com [USA].

Elevated prolactin can cause low LH, FSH, T and dopamine, the latter can contribute to depression and lack of joy/satisfaction. Typical cause is a prolactin secreting pituitary adinoma and treatment to shrink and maintain is 0.5mg cabergoline per week. If you take that, MRI to visualize may fail.

Pregnenolone is made in mitochondria in every cell in your body with the testes been particularly active and with hCG that should be supported.

Training with thyroid problems and low-T typically in young guys is fueled with adrenalin taking over for lost natural energy, then there are cortisol disturbances, adrenal issues, increased rT3 - see references above.

What is anastrozole dosing for 2nd labs?

Please read the stickies found here: About the T Replacement Category

  • advice for new guys - need more info about you
  • things that damage your hormones
  • protocol for injections
  • finding a TRT doc

Evaluate your overall thyroid function by checking oral body temperatures as per the thyroid basics sticky. Thyroid hormone fT3 is what gets the job done and it regulates mitochondrial activity, the source of ATP which is the universal currency of cellular energy. This is part of the body’s temperature control loop. This can get messed up if you are iodine deficient. In many countries, you need to be using iodized salt. Other countries add iodine to dairy or bread.

KSman is simply a regular member on this site. Nothing more other than highly active.

I can be a bit abrupt in my replies and recommendations. I have a lot of ground to cover as this forum has become much more active in the last two years. I can’t follow threads that go deep over time. You need to respond to all of my points and requests as soon as possible before you fall off of my radar. The worse problems are guys who ignore issues re thyroid, body temperatures, history of iodized salt. Please do not piss people off saying that lab results are normal, we need lab number and ranges.

The value that you get out of this process and forum depends on your effort and performance. The bulk of your learning is reading/studying the suggested stickies.


Thanks for the long reply.

In the thyroid sticky it says “If the nodules produce all of the hormones that your body needs, TSH is shut off [TSH–>0] and one is on the edge of hypothyroidism. If the nodules produce more than that, TSH cannot go negative and serum thyroid hormones can go to high and now one has hypothyroidism, which is a serious problem.”

This seems to contradict what you have said above, did you mean that fT3, fT4 are stating hypo and TSH is stating hyper or have I misunderstood?

I have just bought a thermometer and will get back to you about temperatures.
I think I may have supplemented iodine at one time after reading your posts but discontinued it. I haven’t ever used iodized salt.

Surprisingly my E2 has been even lower than that in the past but I do not remember experiencing low libido then, but yes I get very irritable.

I was dosing the adex for 7 days prior to that lab, but I am currently running testosterone higher at 500mg/wk. Adex dosage is 0.5mg Eod. My estrogen has been from the low end to the high end in the last few months with no effect on libido, just acne and mood. Maybe the inconsistent E2 is problematic?

I have ordered some pregnenolone. If I test cortisol, I assume I would need to not be using the pregnenolone prior to the test. Is this correct? How long would I have to have not been taking the pregnenolone for?

DHEA, LH and FSH were checked by myself through private labs:

D.H.E.A. SULPHATE 11.410 umol/L 0.440 - 13.400
FOLLICLE STIM. HORMONE 2.95 IU/L 1.500 - 12.400
LUTEINISING HORMONE 4.22 IU/L 1.700 - 8.600

But I did not check prolactin. I have checked prolactin a few times while on trt and it has always been at a good level other than when taking the caber.


Iodized salt was introduced in 1922 in many countries to address problems that afflicted most of the planet. It is insane how public and school health education and the medical community has forgotten. Drug reps are healthy.

Who else in your home is iodine deficient? - temperatures!

If you can’t get a steady protocol, you will never have E2 managed well. If E2 is getting high, SHBG may increase and when you get off the blast, that is a an anchor. E2 opposes FT at T receptors and the gene expression of elevated E2 is contrary to the desired effects of T. Elevated E2 is bad for arteries and prostate, as well as mood and tolerance. With lower E2 you should be cool and calm and not easily angered.

You front end cortisol with progesterone, not pregnenolone.
Get an AM Cortisol baseline first! Maybe no problem?

Your thyroid labs are complex because with hyper TSH would be low. Your labs are contradictory, but rT3 might explain the riddle. That is the way that I see this. Doctors would be almost universally clueless. Need body temperatures to clarify.


I imagine they’re all deficient, I’ll have check theirs too.

Okay I’ll make more of an effort to get E2 in the right place in future.

I think there is a mistake in the sticky, it says that low TSH means hypo, unless I’m reading it wrong.

Temperature was 36.2 degrees C this morning and now reads 37.1 at 6pm. Not sure if the thermometer was positioned correctly in my mouth this morning. Will continue to record temperatures. What time should I record PM?


As stated: Mid-afternoon should be your peak temperature.

With hyper, there are nodules making thyroid hormones that are outside of the TSH control loop. Normally thyroid only makes hormones with TSH permission. With hypo and high levels of thyroid hormones, the control loop keeps lowering TSH as the problem progresses to the point where thyroid hormones can be toxic high and TSH very low.

I will try to find that hyper/hypo mix up and fix it.