Does TRT Make You Infertile? Truth About TRT & Sperm Health 

Navigating The Hidden Fertility Risks of Testosterone Replacement Therapy.

One of the most common questions men ask before starting testosterone replacement therapy is: "Does TRT make you infertile?" It's a question that deserves a straight answer, because the data might surprise you. 

TRT has transformed millions of lives, helping men reclaim their energy, strength, and confidence. But there are documented risks that many men don't fully grasp until it's too late: testosterone therapy can severely impact your fertility and sperm production.

If you're considering TRT or already on treatment and planning to have kids someday, you're making a decision that may fundamentally change your reproductive timeline. 

The question isn't whether TRT affects fertility—it's how much, how fast, and whether you'll fully recover.

Let's dive into how this all works, what the research actually shows about male fertility while on TRT.

How Male Fertility Actually Works

Let’s take a bottom up approach here. To understand how TRT affects fertility, you first need to understand how sperm production happens in the body.

Male fertility depends on a finely tuned system called the hypothalamic–pituitary–gonadal (HPG) axis.

Here’s how it works:

1. The hypothalamus in your brain releases GnRH (gonadotropin-releasing hormone).
   
   
2. GnRH signals your pituitary gland to release LH (luteinizing hormone) and FSH (follicle-stimulating hormone).
   
   
3. LH and FSH travel through your bloodstream to the testes, where they stimulate two critical things:
   
   
   • LH: Triggers the Leydig cells to make testosterone.
     
   • FSH: Stimulates the Sertoli cells, which are responsible for sperm production.

So yes, testosterone plays a key role. 

But it’s definitely not the only hormone involved and importantly, your body needs to make testosterone in the testes for sperm production to occur. 

That’s where TRT throws a wrench in the system.

What TRT Does to Your Body

TRT (testosterone replacement therapy) is designed to raise testosterone levels by introducing synthetic testosterone from an external source—usually through injections or gels.

While this can relieve symptoms of low testosterone, it also disrupts the body’s natural hormone feedback loop. (And yes, sperm production.) 

TRT and the Feedback Shutdown

When you start TRT, your body senses that testosterone levels are high. In response, your brain reduces production of GnRH, which lowers LH and FSH output from the pituitary gland. Without LH and FSH, your testes stop receiving the signals they need to make sperm and testosterone naturally.

In short:
TRT boosts testosterone levels in the blood, but shuts down the system that drives sperm production.

The Possible Result: Lower Sperm, or None at All

In many men, this hormonal shutdown leads to a significant drop in sperm count (called oligospermia), and in some, it can result in azoospermia, or complete absence of sperm. 

The degree of suppression depends on several factors:

• Dose of testosterone
  
• Type of TRT (injection vs. gel vs. pellet)
  
• Duration of use
  
• Age and baseline fertility

It’s important to note that these effects are often reversible after stopping TRT, but not always, and recovery can take months or even years.

Don’t take my word for it, let’s look at what research actually says about sperm loss on TRT.

Does TRT Make You Infertile? What the Studies Say

So, does TRT make you infertile? The short answer: It can. 

Research shows that testosterone replacement therapy can dramatically reduce sperm production. In some men, sperm count drops to low levels, while in others, it can shut down entirely. 

However, there are some men, in the minority, who may see little to no change, especially on moderate TRT. But, there’s no reliable way to predict who will be affected, so if fertility matters to you right now, it's risky to assume no change.

What the Research Says

Key terms to remember:

Oligospermia = low sperm count

Azoospermia = no sperm at all 

• In a large multicenter WHO trial involving 271 healthy men on 200 mg weekly testosterone enanthate, 65% became azoospermic within 4 months, and an additional 32% developed severe oligospermia (sperm <5 million/mL) by 6 months
  
• TRT can affect some men more than others. A broader WHO Task Force study found 91% of Asian men became azoospermic after 6 months of receiving 200 mg testosterone enanthate weekly. In contrast, contrasted to 60–67.8% of non‑Asian men reached azoospermia over the same period
• An older 1988 study comparing steady-release implants to injections showed about 50–66% of men became azoospermic in both groups after 2–4 months, though sperm production recovered by month six

While most men experience sperm suppression, some (particularly on lower doses or short-term TRT) may maintain sufficient sperm levels for fertility. 

A Better Way: How Enclomiphene Works Differently

For men who are dealing with low testosterone, but want to maintain their fertility, it’s worth considering an off-label treatment called enclomiphene. 

While enclomiphene is not considered to be testosterone replacement therapy, it can boost your body's natural production of testosterone. 

Unlike TRT, which introduces external testosterone and shuts down the body’s hormone signaling, enclomiphene works by stimulating your body to produce its own testosterone, while keeping sperm production intact.

How It Works

Enclomiphene is a selective estrogen receptor modulator (SERM). 

It blocks estrogen receptors in the hypothalamus, which tricks your body into thinking estrogen levels are low. 

In response, your brain ramps up the release of GnRH, which increases LH and FSH—the two hormones your body needs to:

• Signal the testes to produce testosterone
  
• Stimulate sperm production (spermatogenesis)
  

In simpler terms: enclomiphene may increase testosterone levels, without turning off the system that makes sperm

You may have heard of Clomid (clomiphene citrate), a fertility drug sometimes prescribed off-label for men. Treatment with enclomiphene (one of Clomid’s two isomers) isolates the active, testosterone-boosting isomer.

What the Clinical Evidence Tells Us

In two randomized, double-blind phase III trials, researchers compared enclomiphene to topical testosterone gel in men with secondary hypogonadism. 

After 16 weeks:

• Testosterone levels rose significantly in both groups
  
• LH and FSH increased in the enclomiphene group, but decreased in the testosterone gel group
  
• Most importantly:
  Sperm counts remained stable in the enclomiphene group
  Sperm counts dropped sharply in the testosterone gel group

In fact, nearly half of the men using topical testosterone fell below the threshold for healthy sperm levels (15 million/mL), compared to only about 5% of men using enclomiphene, comparable to placebo. 

Why This Matters

If you're looking to raise testosterone without risking infertility, enclomiphene may offer a path forward:

• It restores natural testosterone production
  
• It maintains fertility by keeping LH and FSH active
  
• It avoids the testicular shrinkage and sperm suppression often seen with TRT

This type of treatment focuses on triggering restoration, not replacement.

Who Should Consider Enclomiphene Instead

Enclomiphene isn’t right for everyone, but it may be a smart, targeted option for a specific group of men.

You Might Be a Good Fit If:

• You have secondary hypogonadism (your low testosterone is due to a signaling issue, not testicular damage)
  
• You’re trying to conceive now or want to preserve your fertility for the future
  
• You want to boost testosterone without shutting down sperm production
  
• You prefer a non-injection, oral medication
• You’ve experienced side effects from TRT or didn’t like the idea of being on lifelong hormone replacement
  

Not Ideal For:

• Men with primary hypogonadism (testicular failure) — enclomiphene works through the brain-to-testes hormone loop, so if the testes can't respond, it won’t help
  
• Anyone looking for rapid testosterone spikes for bodybuilding or performance enhancement
  
• Men with certain pituitary disorders or prior brain surgery/trauma that disrupts LH/FSH signaling
  

A Note on Off-Label Use:

Enclomiphene is not FDA-approved yet for testosterone restoration, so it’s considered off-label in the U.S. That said, it’s been used in clinical practice and studied extensively for this exact purpose—and the safety profile so far is favorable in most men.

See If You Qualify For Fertility-Safe TRT Alternative Treatment

If you're dealing with symptoms of low testosterone but worried about protecting your fertility, you're not out of options. You may be a good candidate for treatment with enclomiphene.

At Strut Health, we make treatment easy. Take our simple medical questionnaire to see if you qualify for treatment with Strut Mojo containing Enclomiphene. 

Start your 100% online treatment with Strut today.