Doctors may prescribe testosterone replacement therapy to treat low testosterone levels. It can cause benefits and side effects and may not be safe for people who have a high risk of certain health conditions.

TRT is an acronym for testosterone replacement therapy, sometimes called androgen replacement therapy. It’s primarily used to treat low testosterone (T) levels, which can occur with age or as a result of a medical condition.

But it’s becoming increasingly popular for non-medical uses, including:

  • enhancing sexual performance
  • achieving higher energy levels
  • building muscle mass for bodybuilding

Some research suggests that TRT may in fact help you achieve some of these goals. But there are some caveats. Let’s dive into what exactly happens to your T levels as you get older and what you can realistically expect from TRT.

Your body naturally produces less T as you age. According to an article in American Family Physician, the average male’s T production goes down by about 1 to 2 percent each year.

This is all part of a completely natural process that starts in your late 20s or early 30s:

  1. As you age, your testicles produce less T.
  2. Lowered testicular T causes your hypothalamus to produce less gonadotropin-releasing hormone (GnRH).
  3. Lowered GnRH causes your pituitary gland to makes less luteinizing hormone (LH).
  4. Lowered LH results in lowered overall T production.

This gradual decrease in T often doesn’t cause any noticeable symptoms. But a significant drop in T levels may cause:

  • low sex drive
  • fewer spontaneous erections
  • erectile dysfunction
  • lowered sperm count or volume
  • trouble sleeping
  • unusual loss of muscle and bone density
  • unexplained weight gain

The only way to know whether you truly have low T is by seeing a healthcare provider for a testosterone level test. This is a simple blood test, and most providers require it before prescribing TRT.

You may need to do the test several times because T levels are affected by various factors, such as:

  • diet
  • level of fitness
  • time of day the test is done
  • certain medications, like anticonvulsants and steroids

Here’s the breakdown of typical T levels for adult males starting at age 20:

Age (in years)T levels in nanograms per milliliter (ng/ml)
20–25 5.25–20.7
25–30 5.05–19.8
30–35 4.85–19.0
35–40 4.65–18.1
40–45 4.46–17.1
45–50 4.26–16.4
50–55 4.06–15.6
55–60 3.87–14.7
60–65 3.67–13.9
65–70 3.47–13.0
70–75 3.28–12.2
75–80 3.08–11.3
80–85 2.88–10.5
85–90 2.69–9.61
90–95 2.49–8.76
95–100+ 2.29–7.91

If your T levels are only slightly low for your age, you probably don’t need TRT. If they’re significantly low, your provider will likely do some additional testing before recommending TRT.

There are several ways to do TRT. Your best option will depend on your medical needs as well as your lifestyle. Some methods require daily administration, while others only need to be done on a monthly basis.

TRT methods include:

There’s also a form of TRT that involves rubbing testosterone on your gums twice daily.

TRT is traditionally used to treat hypogonadism, which occurs when your testes (also called gonads) don’t produce enough testosterone.

There are two types of hypogonadism:

  • Primary hypogonadism. Low T results from issues with your gonads. They’re getting signals from your brain to make T but can’t produce them.
  • Central (secondary) hypogonadism. Low T results from issues in your hypothalamus or pituitary gland.

TRT works to make up for T that isn’t being produced by your testes.

If you have true hypogonadism, TRT can:

  • improve your sexual function
  • boost your sperm count and volume
  • increase levels of other hormones that interact with T, including prolactin

TRT can also help to balance unusual T levels caused by:

  • autoimmune conditions
  • genetic disorders
  • infections that damage your sex organs
  • undescended testicles
  • radiation therapy for cancer
  • sex organ surgeries

Many countries, including the United States, don’t allow people to legally purchase T supplements for TRT without a prescription.

Still, people seek out TRT for a range of non-medical reasons, such as:

  • losing weight
  • increasing energy levels
  • boosting sexual drive or performance
  • raising endurance for athletic activities
  • gaining extra muscle mass for bodybuilding

TRT has indeed been shown to have some of these benefits. For example, a recent review concluded that it effectively increased muscle strength in middle-aged and older males.

But TRT has few proven benefits for people, especially younger males, with normal or high T levels. And the risks may outweigh the benefits. A small 2014 study found a link between high T levels and low sperm production.

Plus, using TRT to gain a competitive edge in a sport is considered “doping” by many professional organizations, and most consider it grounds for termination from the sport.

Instead, consider trying some alternative methods for boosting T. Here are eight tips to get you started.

The costs of TRT varies based on what type you’re prescribed. If you have health insurance and need TRT to treat a health condition, you likely won’t pay the full cost. The actual cost may also vary based on your location and whether there’s a generic version available.

Generally, you can expect to pay anywhere from $20 to $1,000 per month. The actual cost depends on a range of factors, including:

  • your location
  • type of medication
  • administration method
  • whether there’s a generic version available

When considering the cost, keep in mind that TRT simply boosts your T levels. It won’t treat the underlying cause of your low T, so you may need life-long treatment.

Keep it legal (and safe)

Remember, it’s illegal to buy T without a prescription in most countries. If you’re caught doing so, you could face serious legal consequences.

Plus, T sold outside of legal pharmacies isn’t regulated. This means that you could be buying T mixed with other ingredients that aren’t listed on the label. This can become dangerous or even life-threatening if you’re allergic to any of those ingredients.

Experts are still trying to fully understand the risks and side effects of TRT. According to Harvard Health, many existing studies have limitations, such as being small in size or using larger-than-usual doses of T.

As a result, there’s still some debate over the benefits and risks linked to TRT. For example, it’s been said to both increase and decrease the risk of certain types of cancer.

A 2016 article in the journal Therapeutic Advances in Urology suggests that some of these conflicting views are the result of overzealous media coverage, especially in the United States.

Before trying TRT, it’s important to sit down with your healthcare provider and go over all the potential side effects and risks. These may include:

You shouldn’t undergo TRT if you’re already at risk for any of the conditions listed above.

TRT has long been a treatment option for people with hypogonadism or conditions associated with reduced T production. But its benefits for those without an underlying condition aren’t as clear, despite all the hype.

Talk to your doctor before you take any T supplements or medications. They can help you determine whether your goals with TRT are safe and realistic.

It’s also important to be monitored by a medical professional as you take T supplements to note any unwanted symptoms or side effects that may occur during treatment.