Nelson Vergel
Founder, ExcelMale.com
Eleven new testosterone studies hit PubMed this week. Here are the five most useful for men on TRT or thinking about it. Each summary is based on the published abstract, with a link to the paper.
1. Low libido? Your T-to-estradiol ratio may matter more than T alone
Freddi R et al. Int Urol Nephrol. Read the study
Researchers in Brazil reviewed 228 men (average age 61) at a sexual medicine clinic. Low libido affected 42% of men with testosterone under 300 ng/dL. It affected 52% of men whose testosterone-to-estradiol ratio was 10 or lower. A low ratio tripled the odds of low libido (OR 3.47) and held up after adjusting for age, whatever the man's total testosterone.
What it means for you: If libido stays low despite decent testosterone, ask your doctor to look at estradiol too. This was a retrospective study, and libido was measured with one yes/no question.
2. Ten weeks of Army training raised low testosterone by 76%
Sekel NM et al. J Appl Physiol. Read the study
The US Army tracked 97 men and 105 women through basic combat training. Men who started with low testosterone saw it rise 76%. By week 4 their levels had stabilized in the normal range at about 345 ng/dL. Men who started normal rose 23%. Testosterone changes did not predict gains in lean mass or losses in fat.
What it means for you: In young men, low testosterone can reflect lifestyle and improve with structured training. Retesting after lifestyle changes makes sense before starting treatment.
3. Subcutaneous testosterone cypionate kept levels stable
Tadeo Morant E et al. Endocrinol Diabetes Nutr. Read the study
A Spanish hospital followed 28 transgender men on weekly under-the-skin injections of testosterone cypionate, starting at 50 mg per week. Average testosterone was 6.2 ng/mL at 2 months and 5.1 ng/mL at 6 months. A quarter needed a dose change. Polycythemia was uncommon. Nobody had injection-site reactions, and all were satisfied with the method.
What it means for you: More support for subcutaneous injections as a practical option with smaller needles. The sample was small and had no comparison group.
4. Testosterone did not drop after prostate removal surgery
Heracek J et al. Prostate. Read the study
A Czech team measured 34 hormones in 173 men before robotic prostatectomy and again at 3 and 6 months. Testosterone and DHT showed no significant change at 6 months. An adrenal androgen, 11-ketotestosterone, rose about 25% to 36%. Cortisol and corticosterone fell.
What it means for you: Prostate removal by itself did not significantly lower testosterone over 6 months in this group.
5. High-dose testosterone as a prostate cancer treatment (review)
Rival PM et al. Curr Urol. Read the review
"Bipolar androgen therapy" swings testosterone between very high and near-zero levels. In early trials with more than 250 men whose cancer had stopped responding to hormone blockade, about 25% to 30% had PSA or scan responses. The clearest benefit was making later hormone-blocking drugs work again. It remains experimental, with no phase III survival data yet.
What it means for you: The old idea that testosterone always feeds prostate cancer keeps getting more complicated. This is a narrative review, not new data.
Also published this week
1. Low libido? Your T-to-estradiol ratio may matter more than T alone
Freddi R et al. Int Urol Nephrol. Read the study
Researchers in Brazil reviewed 228 men (average age 61) at a sexual medicine clinic. Low libido affected 42% of men with testosterone under 300 ng/dL. It affected 52% of men whose testosterone-to-estradiol ratio was 10 or lower. A low ratio tripled the odds of low libido (OR 3.47) and held up after adjusting for age, whatever the man's total testosterone.
What it means for you: If libido stays low despite decent testosterone, ask your doctor to look at estradiol too. This was a retrospective study, and libido was measured with one yes/no question.
2. Ten weeks of Army training raised low testosterone by 76%
Sekel NM et al. J Appl Physiol. Read the study
The US Army tracked 97 men and 105 women through basic combat training. Men who started with low testosterone saw it rise 76%. By week 4 their levels had stabilized in the normal range at about 345 ng/dL. Men who started normal rose 23%. Testosterone changes did not predict gains in lean mass or losses in fat.
What it means for you: In young men, low testosterone can reflect lifestyle and improve with structured training. Retesting after lifestyle changes makes sense before starting treatment.
3. Subcutaneous testosterone cypionate kept levels stable
Tadeo Morant E et al. Endocrinol Diabetes Nutr. Read the study
A Spanish hospital followed 28 transgender men on weekly under-the-skin injections of testosterone cypionate, starting at 50 mg per week. Average testosterone was 6.2 ng/mL at 2 months and 5.1 ng/mL at 6 months. A quarter needed a dose change. Polycythemia was uncommon. Nobody had injection-site reactions, and all were satisfied with the method.
What it means for you: More support for subcutaneous injections as a practical option with smaller needles. The sample was small and had no comparison group.
4. Testosterone did not drop after prostate removal surgery
Heracek J et al. Prostate. Read the study
A Czech team measured 34 hormones in 173 men before robotic prostatectomy and again at 3 and 6 months. Testosterone and DHT showed no significant change at 6 months. An adrenal androgen, 11-ketotestosterone, rose about 25% to 36%. Cortisol and corticosterone fell.
What it means for you: Prostate removal by itself did not significantly lower testosterone over 6 months in this group.
5. High-dose testosterone as a prostate cancer treatment (review)
Rival PM et al. Curr Urol. Read the review
"Bipolar androgen therapy" swings testosterone between very high and near-zero levels. In early trials with more than 250 men whose cancer had stopped responding to hormone blockade, about 25% to 30% had PSA or scan responses. The clearest benefit was making later hormone-blocking drugs work again. It remains experimental, with no phase III survival data yet.
What it means for you: The old idea that testosterone always feeds prostate cancer keeps getting more complicated. This is a narrative review, not new data.
Also published this week
- Men with more women coworkers had lower testosterone in US survey data (Demography). Association only.
- Sulfur dioxide air pollution was linked to lower testosterone in 3,284 Chinese fertility patients (Environ Toxicol Pharmacol).
- Flame retardant chemicals in urine were linked to abnormal sperm shape and a higher estradiol/testosterone ratio in Taiwanese men (Environ Toxicol Pharmacol).
- In men without sperm, the inhibin B/FSH ratio predicted sperm retrieval (73 men, PeerJ). AMH did not (58 men, Turk J Obstet Gynecol).
- Among Swedish men tested for steroids at police request, users had more drug and weapons convictions (Drug Alcohol Depend). This does not describe supervised TRT patients.
