Thinking about starting testosterone replacement therapy (TRT) but unsure about the risks and benefits?
You’re not alone. At Men’s Medical Clinic, we speak to men every day with important questions about how TRT affects fertility, mood, heart health, prostate cancer risk, and more. In this guide, we answer the most common questions patients ask. These can be from whether TRT causes “roid rage” or acne, to how it impacts sperm production and long-term health. Whether you’re considering treatment or already on it, this article will help you make informed, evidence-based decisions about your health and hormone therapy.
Will TRT affect my fertility?
When you start testosterone therapy your brain reduces LH and FSH, so your testes make less sperm. Over 90 percent of men on standard TRT develop very low sperm counts within six months. Most recover fertility once you stop treatment—two-thirds within six months and nearly all within two years. To preserve options you can bank sperm beforehand or add low-dose HCG alongside TRT.
How does TRT affect fertility?
Normally, your brain (specifically the pituitary gland) produces signalling hormones called LH (luteinising hormone) and FSH (follicle stimulating hormone). These act on your testes to stimulate testosterone production and sperm production.
When you start TRT, your body senses that you now have enough testosterone coming from outside. As a result, your brain reduces LH and FSH production.
Less LH and FSH means your testes produce less of their own testosterone and less sperm. Essentially, TRT can “switch off” your sperm production.
How significant is the effect?
In a major Chinese study (Gu Y et al, 2009), men who took monthly testosterone injections for 6 months achieved azoospermia rates (very low sperm counts under 1 million/ml) in 93-98% of cases.
So yes, testosterone therapy can significantly reduce your fertility, even after a relatively short time. But it’s not completely consistent – some men maintain low but present sperm counts while on TRT.
What are your options if you want children?
1. Stop TRT and let your fertility recover
Stopping testosterone replacement therapy allows your brain to start producing LH and FSH again, which restimulates sperm production.
A study by Desai et al (2022) showed that 67% of men recovered a sperm concentration of 20 million/ml within 6 months. 90% recovered within 12 months, and nearly all men recovered within 24 months.
So, fertility recovery is possible for most men – but it can take time.
2. Freeze your sperm before starting TRT
If you’re unsure about your future plans for children, freezing sperm (sperm banking) before starting treatment is a wise option.
It does come with upfront costs and ongoing storage fees, but it gives you peace of mind. At Men’s Medical Clinic, we discuss this option with all men before starting TRT.
3. Use HCG to maintain fertility during TRT
HCG (human chorionic gonadotropin) is a hormone that mimics LH. It stimulates your testes to continue producing testosterone and sperm even while you’re on TRT.
Here’s what the evidence says:
Kim et al (2012) found HCG maintained fertility in men taking testosterone
Matsumoto et al (2009) studied men with severe hypogonadism and found HCG improved and maintained sperm production
Bouloux et al (2002) found HCG restored sperm production in men with hypogonadotropic hypogonadism
Historically, HCG has been expensive and difficult to source, but this is improving in the UK.
Final thoughts
TRT is an incredibly effective treatment for men with low testosterone. But fertility is an important consideration, and it’s a discussion your doctor should always have with you before starting treatment.
At Men’s Medical Clinic Leeds, we specialise in testosterone replacement therapy and men’s health. If you’re considering TRT and want to discuss your fertility options, book a consultation today. We’re here to guide you safely through your treatment and ensure all aspects of your health are covered.
Does TRT increase prostate cancer risk?
No. The TRAVERSE trial (5,200 men over three years) found identical rates of prostate cancer, high-grade disease and urinary issues in TRT and placebo groups. We still screen PSA and prostate health before treatment, but for men without existing prostate problems there’s no proven link between TRT and prostate cancer.
Does TRT Cause Prostate Cancer?
This is a question I get asked all the time.
The short answer is no. There is no current evidence for this.
In fact, the TRAVERSE trial was the largest randomised control trial (RCT) to date looking at this question. It included over 5,200 men with hypogonadism.
Men were randomised to either testosterone gel or placebo and followed up for around three years. Interestingly, the incidence of prostate cancer – including high-grade cancers – urine retention, prostate biopsies, and even lower urinary tract symptoms did not significantly differ between the two groups.
PSA levels did rise slightly in the first 3-12 months after starting TRT, but after 12 months there was no significant difference between the TRT and placebo groups.
Like any study, we need to consider its limitations. I always tell my patients that men were only followed up for 36 months, and as we know, cancer can develop over a longer time period than this. Secondly, those already at higher risk – such as men with prostate cancer or a PSA over 3 – were excluded from the study.
But the TRAVERSE trial was monumental. Previously, the fear of prostate cancer stopped a lot of doctors from prescribing testosterone replacement therapy. This study should raise confidence in the profession that prescribing TRT is safe for men without existing prostate issues.
At Men’s Medical Clinic in Leeds, we specialise in testosterone replacement therapy and men’s health. If you’re experiencing low energy, poor libido, or symptoms of low testosterone and want evidence-based guidance tailored to you, book an appointment today. We’re here to optimise your health and help you feel your best.
Will TRT make me aggressive or give me “roid rage”?
No. Even studies using very high, non-medical testosterone doses showed no increase in anger or aggression versus placebo. Restoring physiological testosterone levels under medical supervision does not cause “roid rage.”
Does TRT Cause Roid Rage?
You’ve probably seen news stories about anabolic steroid users going on aggressive rampages and the dangers of “steroids”.
But is that the same as TRT?
In a nutshell, there is no good evidence that testosterone replacement therapy causes “roid rage” or aggression.
One interesting study by Tricker et al in 1996 looked at this exact question. They studied 43 men with normal testosterone levels and gave them very high doses of testosterone enanthate – 600mg per week. This is far higher than standard TRT doses used to treat hypogonadism.
It was a double-blind, placebo-controlled study, and the men were randomised into four groups:
Group I – placebo, no exercise
Group II – testosterone enanthate, no exercise
Group III – placebo, exercise
Group IV – testosterone enanthate plus exercise
The men completed detailed anger and mood questionnaires, and their spouses or live-in relatives filled in observer questionnaires too.
What did they find?
There were no differences in anger, mood, or aggression between any of the groups, even in those on very high testosterone doses.
So with TRT, you can rest assured you’re not going to turn into the Incredible Hulk. Properly prescribed testosterone therapy for low testosterone is designed to restore normal healthy levels, not to push you into the supraphysiological ranges used by bodybuilders.
At Men’s Medical Clinic in Leeds, we specialise in testosterone replacement therapy and men’s health. If you’re experiencing symptoms of low testosterone and want expert, evidence-based care, book a consultation today. We’re here to help you optimise your health safely and effectively.
Can TRT cause heart attacks or heart disease?
Current evidence shows no increase in cardiovascular events with TRT. Large trials and meta-analyses find no higher rates of heart attack, stroke or heart disease in men treated to guideline levels versus controls.
Can TRT cause gynecomastia?
True gynecomastia is rare and usually driven by excess aromatization of testosterone into estrogen in fat tissue. If you’re at risk—higher body-fat or genetic predisposition—we can add a short course of anastrozole to block estrogen formation and protect against breast-tissue growth.
What about acne on TRT?
Some men notice increased oiliness or acne when testosterone rises. A topical therapy like Duac gel often controls breakouts. If it persists, we can refer you to dermatology for advanced treatment.
What testosterone levels do you treat?
We follow BSSM guidance, generally treating men with morning testosterone below 12 nmol/L plus symptoms. In select patients who feel symptomatic despite levels up to 15 nmol/L—often due to androgen sensitivity differences—we may also offer TRT after careful discussion.
What treatment options do you offer?
We tailor the approach to your goals and lifestyle:
• Nebido (long-acting injection) every 10–14 weeks plus administration fee
• Testosterone cypionate or enanthate via weekly or micro-dosed injections
• Testosterone gels for daily dosing
• HCG to maintain fertility during TRT
• Clomifene to stimulate your own hormone axis and preserve sperm
How much does TRT cost per month?
Once you’re stable, typical monthly costs range between £100 – £200, covering treatment fees, monitoring bloods every 3–6 months and injection administration. Medication costs vary by pharmacy.
Where can I be seen?
We offer fully confidential remote consultations and face-to-face appointments at our CQC-registered satellite clinic in Leeds (Tower Clinic, Tinshill Lane, Cookridge).
Do you offer a membership service?
Yes—our first membership plans are launching soon, bundling unlimited Q&A calls, priority appointments and discounted monitoring. Join our mailing list to be the first to know.