How Long Does TRT Take to Work? (Effects & Results Timeline)

It can take anywhere from a few hours to a week for testosterone to increase with TRT. And it all depends on the type of testosterone replacement therapy and the dosage that a doctor recommends.

I know that might sound like a crazy long-range plan, but there is a good reason for that.

It’s also important to highlight that having a measured increase in low testosterone doesn’t automatically mean that you’ll see immediate improvements in your health.

Let me explain.

If a doctor prescribes a high dose of testosterone injections every five days, then you could have a measurable increase in serum testosterone within hours.

Doctors generally say that you’ll get the peak measurement after about 48 hours, and then it will gradually decline [1].

Compared to testosterone injections, a topical testosterone gel could take several weeks to significantly build up low T levels.

However, these gels have the advantage that they tend to provide a more stable level, and, of course, you don’t have to be concerned about injections.

You also have to factor in how high the dose is and how often you get the treatment. The higher and more often you take TRT injections or a gel, the sooner you’ll notice an increase.

In this section, I want to address how long it will take to notice some of the short-term effects of taking testosterone injections or gels.

And I have broken it down into four benefits.

1. Increased Physical Energy Levels

One of the first things a lot of people notice after starting testosterone therapy is that they start feeling less fatigued and more energized [2].

It’s not like you’ll turn into The Hulk within days. But it would be quite common to start noticing more physical energy for activities like walking, running, or resistance training.

Based on my experience and feedback from a doctor, you could expect to feel this within 3–5 weeks.

2. Increased Mental Clarity

Another key area where hormone replacement therapy can make a big difference is in brain performance and mental energy [3].

As a personal trainer, I’ve had a lot of clients tell me that they felt more focused and motivated after 2–3 weeks of testosterone levels being back in the normal range.

And it seems to primarily reduce the amount of brain fog you get throughout the day, where you just struggle to keep your mind on one task.

Now, let’s turn to some long-term benefits that might only start kicking in after a month or two. For some men, it may also be a slow and gradual improvement over several months.

1. Improved Libido

Low testosterone levels can have a significant impact on sex drive. And I have to highlight that low sex drive isn’t the same as erectile dysfunction (ED) [6].

What this means is that testosterone therapy isn’t a solution for ED, but it could be an underlying issue of low sex drive.

It seems like men start to notice improvement in libido after about six weeks, and this can gradually improve further over the months ahead.

“Your libido is powered in part by your overall physical health, including your genes and hormones such as testosterone.”- Melinda Ratini, MS, DO

While I was doing this research with a doctor, he mentioned one thing to me that he recommends all men do once they start testosterone treatment.

Start keeping a daily journal where you write things down about how you physically and mentally feel.

Also, write down any differences you notice, like changes in body hair, feeling less stressed, increased or decreased energy, sexual function, and anything else that comes to mind.

During repeat consultations, your doctor will ask you questions about changes in how you feel, and he will compare them to your results from hormone tests.

What this does is provide a full picture of how well the treatment is working, and it helps to make educated and measured changes to the dosage.