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Dr. Andrew Rynne

Family Physician

Exp 50 years

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What causes a reduction in the free testosterone levels?

Answered by
Dr. Elona Xhardo


Practicing since :2008

Answered : 706 Questions

Posted on Mon, 8 Oct 2018 in General Health
Question: Hi Dr. Xhardo. I hope all is well with you. I am following up on our previous discussions about my Testosterone Replacement Therapy.

My history is that I was on 5 g of androgel for 3 months and it resulted in a Free Testosterone level of only 120pmols/L. So it was increased to 10g per day and after 4 weeks on the new dose my Free Testosterone up to 429 and symptoms were much improved.

But after a further 2 weeks its back down to 218. What would be causing this reduction? Am i converting the Testosterone to estrogen or am I increasing my SHBG or is it something else? Thank you. XXXXXXX
Answered by Dr. Elona Xhardo 17 hours later
Brief Answer:

I would recommend to do some additional tests.

Detailed Answer:


For men, SHBG levels are stable through adulthood until mid to late life when it then increases, at the same time testosterone begins to decrease.

This combination of high SHBG and low testosterone may lead to hypogonadism which can benefit from testosterone replacement therapy (like in your case).

SHBG is the carrier molecule which transports sex-steroids, like testosterone, within in the bloodstream and around the body.

When testosterone is bound to SHBG it is said to be ‘inactive’ meaning it is not ‘free’ or bioavailable to act on targets tissues. There is a delicate and complex balance that occurs within the body between the sex-steroids for these binding sites so when the amount of SHBG alters from the norm various hormonal conditions may arise.

Occasionally when SHBG is high it can hinder the effects of testosterone creams.

In these cases where the total testosterone levels is within normal range and symptoms are still apparent then further investigation as to why SHBG is high may be considered.

(You didn't mention if you have done the Total Testosterone test)

Increased SHBG levels may be suggestive of liver disease, hyperthyroidism eating disorders such as anorexia or smoking.

In these cases, some lifestyle measures may be beneficial to reduce SHBG such as stopping smoking.

Your blood test may also include the Free Androgen Index (FAI). It approximates how much of the testosterone is ‘free’ testosterone.

To resume: If you have used AndroGel exactly as it was prescribed by your doctor and although this, your increased free T level drop suddenly and your symptoms of "low Testosterone" reappear, I would recommend checking the SHBG, the total testosterone and Free Androgen Index.

In conjunction with blood tests, it is also important to consider how you are responding to testosterone therapy.

If you are feeling a benefit then don’t get too ‘caught up’ in the numbers (unless your doctor is concerned) because as individuals we may respond in different ways.

Hope I have answered your query. Let me know if I can assist you further.
Above answer was peer-reviewed by : Dr. Kampana
Follow up: Dr. Elona Xhardo 8 hours later
Thank you for the very informative answer. My urologist does not think testing for estrogen and SHBG is necessary as he only uses Free Testosterone (and a standard blood panel) together with the patient's symptoms to make clinical decisions. He says estrodiol is rarely out of the normal range with testosterone replacement therapy and SHBG is not easily manipulated with drugs.

So I have to make a decision soon as I have an upcoming appointment and he is going to offer to switch me to injections every two weeks (self administered). I am little uncertain about the peaks and troughs that come with injections but at the current dose androgel is not working well enough for me.

What do you think of trying a higher gel dosage versus the injections? Thank you.
Answered by Dr. Elona Xhardo 22 hours later
Brief Answer:

I will suggest to switch to injections.

Detailed Answer:


It is true that transdermal Testosterone creates more E2 and DHT and you can have "high estradiol symptoms" like sleepiness, tiredness, water retention and weight gain.

So, Under TRT the estradiol level fluctuate and for this, the estradiol test is not indispensable for the follow-up. (I agree with your doctor)

In my experience, other tests like SHBG, the total testosterone and Free Androgen Index are helpful to understand better the actual situation.

If I patient like you, came to my clinic, I would recommend starting with T shots because, in my opinion, this is more effective.

Sometimes the problem is "absorption" (your body won't absorb the entire amount).

It is rare to see a guy on transdermals get to the levels of guys injecting the same quantity of Testosteron/week.

Some cannot absorb at all and some do then it stops. Inability to absorb can be a symptom of hypothyroidism (have you ever done the thyroid tests?)

Given the costs (and waste) of Androgen, high doses are simply expensive.

For this reason, I don't recommend to try higher Androgel doses.

I suggest switching the T therapy to Testosterone Enanthate or Depo-Testosterone 50 to 400 mg IM injection every 2 to 4 weeks.
The shot can be done at home.

Anyway, my advice is to discuss with your treating doctor about the best form and doses of TRT for a better result.

Hope I have answered your query.

Take care

Dr Elona Xhardo, Endocrinologist
Above answer was peer-reviewed by : Dr. Prasad

The User accepted the expert's answer

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