14 October 2021: I’m feeling the impact of low testosterone. From past experience I recognise the subtle changes. For the last couple of months, I’ve generally been a bit more lethargic. I’ve had less physical energy. Even after increasing my daily exercise routine, I am still running slower over my usual Saturday morning 5 kilometre run. And orgasms seem to have become more elusive again.

Today I got the blood test results that confirm my testosterone has dropped from its normal lowish level into the zone where it really affects my mind and body. I also got the good news that my PSA is still undetectable, so my prostate cancer seems still in remission.

In this post there’s a bit more about the symptoms and history that alerted me to the issue. And then there’s the research linking testosterone and prostate cancer and the difficult decisions to make.

How I noticed my testosterone was sinking lower

For the last couple of months I’ve noticed that my core energy has dropped. It has showed in both sexual energy and running – I can do both, but there isn’t the same eagerness and verve.

Physically I’m sometimes capable of penetrative sex. But my erections are not firm enough to reach orgasm in this way. Overall my hopes for further recovery of sexual function have gone into a bit of a decline.

Also my speed over a 5 km run had been slowly improving since my surgery 20 months ago. But for the last couple of months it has slowly declined. I was down to 28 minutes in June; now I can’t get below 30 and often take 32 or 33 minutes to cover the same route.

My history with low testosterone

This reminds me of what happened to me back in 2011. Then aged 53, I remember feeling “over the hill.” I just didn’t feel like exercising, or working in the garden, or going out for runs or walks – all things that normally give me joy and put a spring in my step. I was not much fun to be with – for myself or those close to me. My wife suggested perhaps it was a kind of “male menopause” often described as andropause. Yet we were still sexually active and I thought, wrongly, that meant my hormones were fine.

Here’s what the data showed: in 2011 my testosterone level went into the red zone.

impact of low testosterone

Red and green lines from International Society of Andrology guidelines that came with my lab report

I remember back in 2011, going to see the doctor who later saved my life and she said “sexual dysfunction is often the last symptom that emerges when a man’s testosterone levels get too low.” This fits my experience back then. The impact of low testosterone for me was mostly in my general lethargy and lack of physical strength. Other symptoms commonly include fatigue, reduced lean muscle mass, irritability and depression as well as erectile dysfunction and loss of libido.

This has started again in 2021. Remembering what I felt like ten years ago helped me to recognise the symptoms. And the latest lab results show my testosterone level is dangerously close to the red line again. For those who like numbers, the lab report says total testosterone is down to 9.2 nmol/l, which is 265 ng/dL in US units.

Ten years ago I got treatment that took me out of the danger zone. But with prostate cancer in the mix it’s not that simple.

Research links testosterone with the growth of prostate cancer

Almost everybody who has had a brush with prostate cancer knows it is linked in some way to testosterone. One urologist described it to a friend in this way:

“Testosterone doesn’t cause prostate cancer. But for many prostate cancers, it is like a fertiliser: feeding the growth of the cancer.”

Here’s a review of the research data. One question is about how testosterone promotes the growth of prostate cancer. And the other question that’s top of my mind: is it OK for me to get treatment to raise my testosterone levels?

Dilemmas with low testosterone after prostate cancer

I don’t want my prostate cancer to come back. And I would love to avoid the general fatigue and limpness that comes with low testosterone. It looks to me as a layperson that if there are any stray cancer cells still wandering around in my body, it would be a bad idea to encourage them by artificially boosting my testosterone levels.

My problem is small compared to many others with more advanced cancers. I’m painfully aware that complete hormone suppression treatment is frequently prescribed with similar but much more devastating symptoms to mine. Here’s more about the impact of this treatment for prostate cancer (e.g. Zoladex) and breast cancer(e.g. Tamoxifen).

For now I’ll hold off on any treatment for my low testosterone, push myself to exercise more, and talk to some experts.