Thyroid Cancer / Nodules & Hyperthyroidism Expert Forum
Subclinical Hypothyroidism, High Prolactin and Erectile Dysfunction
About This Forum:

Questions in the Thyroid forum are answered by Mark Lupo, MD. Topics covered include Goiter, Graves Disease, Hyperthyroid, Parathyroid/Calcium Problems, Thyroid Cancer, Thyroid Nodules/Cysts, Thyroiditis, Thyroid & Pregnancy, Thyroid Stimulating Hormone (TSH), Thyroid Tests, and Thyroid Surgery.

Font Size:
This expert forum is not accepting new questions. Please post your question in one of our medical support communities.
Blank Blank

Subclinical Hypothyroidism, High Prolactin and Erectile Dysfunction

I know this topic isn't quite relevant to this forum, but I wanted to ask Dr. Lupo's advice.

I originally went to my GP 9 years ago about erectile issues. My arousal response had become weaker and morning erections had stopped. She ran blood tests, and concluded that everything was normal.

Last month, I visited my new GP about an unrelated issue. This issue was difficult to diagnose, and as such a full panel of blood tests were ordered, showing the following:

TSH: 4.79
T4 free: 16.2
Testosterone: 9.7

This testosterone level is below the "normal" range and is less than half the mean value for a 27 year old male. The TSH level is way over the upper bound of the normal range.

Low testosterone makes sense. It explains the absence of morning erections. It is thought that these nocturnal erections play a role in healthy cavernous vasodilation, thus possibly partially explaining my weakening waking erections.

I got the test results from when I was 18. They showed a developing pattern:

TSH: 3.79
T4: 16.8
Testosterone: 12.5
Prolactin: 299

My TSH levels were above the normal range, my test levels were again roughly half what they should be and crucially, the prolactin level (while clinically normal) is still very high for an 18 year old when measured against mean values. I'm sure if my prolactin levels were measured last month, they would be very high.

Is this correct?:

- My thyroid is underfunctioning so my hypothalmus instructs my pituitary to produce more TSH
- Unfortunately this also causes the pituitary to produce more prolactin, a known dopamine inhibitor (thus weaking erectile response to arousal) and inhibitor of test production
- The increased levels of TSH seem to be keeping the T4 levels normal. More and more TSH is required to do this as I get older, therefore more prolactin is being produced, less testosterone is being produced and my libido and erectile health worsen as a result.

What's your Follicle-stimulating hormone FSH and Luteinizing hormone LH levels, Growth hormone labs?  Did they even do those?

You have any vision problems?
Hi Gibbon,

FSH and LH levels weren't tested this time. Bear in mind I haven't gotten an endo appointment yet.

They were tested when I was 18, and were both in the 5-6 range (i.e. in the middle of the normal ranges).

That was 10 years ago so who knows what they are now. I'm sure they are higher, as my test levels have fallen even further as you can see.

My vision hasn't deteriorated. I did have an aura before the onset of my first ever migraine last month, which scared me as I had never experienced that before. Apparently the onset of migraine is consistent with underactive thyroid too.
Just another question there guys,

If indeed an underactive thyroid is the root of my problems (which seems likely as I have other symptoms too - fatigue despite being super fit; shaking hands; late onset of migraine etc.), what would be the best treatment option?

Surely the usual drugs that are prescribed are pointless in my case as they are basically T4 supplements no?

Would they still bring down my TSH levels (and therefore my prolactin levels)?
You should post the ranges for your labs.  Min and Max. But really hopefully the endocrinologist will sort this out. Me I think your labs are odd, TSH is highish, T4 okayish, T3, not measured. Testosterone not okay. Two things going on. odd.

One thing, low testosterone and low thyroid, both can cause your reported symptoms. Pretty much any endocrine insufficiency, will.  Go read the symptoms of hypo-whatever, they are all mostly the same. Which is why it's important your doctor or order labs to shotgun test them all.

I know your symptoms well, I have central hypothyroidism and have been on replacement therapy for ten years. Same deal, testosterone was at the low range and the original doctor ignored it.

PS: One problem you can have with endocrinologists is lot of them treat mostly diabetes patents. And have not much experience outside that. Also, beware of older male doctors. They all learned in school that erectile dysfunction is a psychiatric problem. If the guy you see is dismissive and tries to talk you out of your symptoms, find another one.

Good luck.
Thanks for the advice. It is an older male doctor that I'm scheduled to see. He's the only endo available in my city.

Did treatment for hypothyroidism stablise your testosterone to normal levels?
Continue discussion Blank
This Forum's Experts
Mark Lupo, M.D.Blank
Thyroid & Endocrine Center of Florida
Sarasota, FL
Weight Tracker
Weight Tracker
Start Tracking Now