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How Long Does Testosterone Therapy Take to Work?

As an older male, I was looking for something to boost my energy and libido. I decided to try testosterone shots, but wondered how long does it take for testosterone injections to work?

It took approximately 12 weeks to feel the full effects of testosterone replacement therapy injections. But after 6 weeks, there were noticeable improvements and there were minor increases each week in energy, libido (sex drive), muscle mass, and improved sleep which also benefits those same issues.

However, an increase in estrogen levels by week 6 also required a prescription to lower those levels as they were counteracting the increase in testosterone.

I chronicled my journey for the 1st 13 weeks of injections since that was what my doctor told me in terms of how long it would take to feel the effects. And I recap my results after 6 months as well.

And below you can see details of the effects, side effects, and how I felt each week.

At age 57 at the time of starting this writing, I had low testosterone levels. They were 350 the first time they took it and 250 the 2nd time (later in the day).

Testosterone naturally drops throughout the day. Any sex or masturbation can lower that number too. So ideally avoid those before getting your numbers tested.

Bear in mind that diet, supplements, exercise, and quality of sleep all affect how high your testosterone is. Although ironically, low testosterone can significantly disrupt your sleep.

But I had been seeing inconsistency with my erection (not sex drive) for years. I bet my struggles with occasional erectile dysfunction started around age 40 after a bad sinus infection that took a year to properly diagnose and treat.

Of course, there are some medical conditions that can cause ED; it’s not just getting older. When in doubt, always talk to your doctor.

I would often take a small amount of viagra to help. But I don’t like the flushing and dull headache that came with that. Plus sometimes the need comes up faster than that works. So that was why I sought out testosterone injections.

I wanted to look at not only erections but also other factors supposedly influenced by a higher testosterone level.

Week-by-week improvements

Week 1

  • Morning Wood –Fairly consistent if I got at least 5-6 hours of sleep
  • Weight – 204
  • Energy level – Normal
  • Erection firmness – 75%
  • Sleep quality – 60% (no trouble falling asleep, but waking up a few times during the night)
  • Testosterone levels – 350 (measured in the morning when they are at their highest)

Week 2

  • Morning Wood – Inconsistent (but so was my sleep and I was fighting off a cold)
  • Weight – 206
  • Energy level – Normal
  • Erection firmness – 80%
  • Sleep quality – 70%
  • Testosterone levels – 250 (measured in the afternoon when they start to wane)

Week 3

  • Morning Wood – Fairly consistent if I got at least 5-6 hours of sleep
  • Weight – 204
  • Energy level – Normal, but I felt a drop later in the week after the shot
  • Erection firmness – 70-80%
  • Sleep quality – 70%

Week 4

  • Morning Wood – Rock solid
  • Weight – 210
  • Energy level – Normal
  • Erection firmness – 80-100%
  • Sleep quality – 70%

Week 5

Note, for week 5, I was gone for spring break with my kids. So I got a 2nd smaller shot at the end of the previous week, and then basically skipped a week. So my next shot was technically my 5th full one but on the 6th week.

  • Morning Wood – Intermittent
  • Weight – 210
  • Energy level – Reduced
  • Erection firmness – 70-80%
  • Sleep quality – 80%

Week 6

I suspected that my estrogen levels (what they call Estradiol) were rising as I honestly felt better at week 3 than at week 6. At the 6 week mark, they automatically do a blood test anyway. Low and behold, I was right. My estrogen levels were elevated. They had warned me of this possibility.

They said that because the body was having the testosterone levels artificially raised, sometimes the body fights back by raising estrogen levels.

Luckily, they just prescribe a once-a-week pill to fight that. So 3 days after my 6th official shot, I took my first pill.

  • Morning Wood – Better
  • Weight – 210
  • Energy level – Flat
  • Erection firmness – 80-90%
  • Sleep quality – 80%
  • Testosterone levels – 636 (had been as low as 250, and the ideal is 827)
  • Estradiol (estrogen) levels – 47 (should be at or below 39)

So my results here are not from the day of the shot, but rather from Thursday (the shot was on Monday). I still want more, so we’ll see how I feel next week after the estrogen levels hopefully subside a little.

Week 7

  • Morning Wood – Good as long as I got at least 6 hours of sleep
  • Weight – 200
  • Energy level – Flat
  • Erection firmness – 80-90%
  • Sleep quality – 80%

Full disclosure; I did have sex once this week (first date, too), and was able to perform well. Maybe not 100%, but definitely better than before.

I did notice my man-boobs had shrunk some, probably due to the estrogen-blocker I had taken the week before.

Week 8

  • Morning Wood – Very strong as long as I got at least 6 hours of sleep
  • Weight – 198
  • Energy level – Good
  • Erection firmness – 90%
  • Sleep quality – 80%

Man-boobs are all but gone.

I also had sex once at the end of this week. As with the previous time, I was able to get and maintain an erection but not as fully as I would ultimately like.

So I am definitely happy with my results so far, but am hoping for more improvements.

Week 9

  • Morning Wood – Very strong as long as I got at least 6 hours of sleep
  • Weight – 200
  • Energy level – Good
  • Erection firmness – 90%
  • Sleep quality – 80%

Overall I’m still hoping for more improvements and my doctor indicated she thought my testosterone levels would eventually get to around 800. At their lowest (at least measured), they were 250, and the last check was 636.

At my age, it’s worth pointing out that my erections are less consistent later in the day or evening. And if I’ve had 2 or more alcoholic drinks in a relatively short period of time, that does have a negative impact too.

The irony is that an early afternoon coffee or energy drink does help with performance later in the day, but also can negatively impact sleep quality (which in turn can impact erections). So it’s a delicate balance.

At one point prior to discovering testosterone replacement therapy, I was taking a lot of supplements to try and boost my testosterone naturally.

Since I never got measured, I have no idea if those had a positive impact or not. But I am considering continuing to take the following in addition to continuing with my weekly shots.

These are all from Amazon, so click the link to see the current price on Amazon:

I did a LOT of research before ordering those products (I’ve used all of them for months, but had stopped re-ordering when I started the shots). They are all quality products, usually with thousands of excellent reviews.

Some of those have even been touted by Joe Rogan.

Week 10

  • Morning Wood – Weak the day I got the shot
  • Weight – 195
  • Energy level – Good
  • Erection firmness – 70%
  • Sleep quality – 80%

In general, I’ve found that the TRT shot hits a day or 2 after I get it, but by the day of my next shot, the effectiveness has worn off some.

Of course, sleep, water, diet, stress, and exercise impact it too. Allergies (which are bad right now) also impact it.

I’ve also noticed that if I take my estrogen blocker pill every 5-6 days instead of every 7 days, I see an improvement. But of course, never do anything that differs from what your doctor is telling you to do.

Week 11

  • Morning Wood – solid
  • Weight – 195
  • Energy level – Good
  • Erection firmness – 90%
  • Sleep quality – 85%

Week 12

    • Morning Wood – solid
    • Weight – 195
    • Energy levels – Good
    • Erection firmness – 90%
    • Sleep quality – 85%

I get my 3rd blood test next week, so I’m looking forward to seeing the results. Overall I’m happy but want more. I’m guessing my testosterone is still in the 600s and the 800s would be better. I also feel like my estrogen levels are probably still on the high side.

We’ll see.

Week 13 – Cancer scare!

Unfortunately at this point, I had to temporarily stop TRT shots as my PSA levels were elevated.

What does that mean? I didn’t know either. My doctor explained that it is a measurement of my prostate and that it indicated the possibility of an enlarged prostate and which could mean cancer.

Now to be sure, TRT does not cause prostate cancer. After all, testosterone is a naturally occurring hormone.

So I was referred to a urologist who conducted their own test and also confirmed high levels. At that point, I was given the choice was waiting and being tested every few weeks for a couple of months (with the TRT shots on hold), or doing a prostate biopsy.

I opted for the biopsy as it could get me answers a lot quicker (very helpful I thought if it was cancer). Plus, since I now had a girlfriend, I didn’t want to give up the TRT shots indefinitely.

So I had the biopsy done the following week and then waited 1 more week for the results.

The biopsy itself is an outpatient procedure with no anesthesia needed. It’s not the most comfortable thing in the world (basically felt like someone put a staple gun up my butt and fired 12 times).

Luckily the biopsy showed no cancer and I was approved (after 3 weeks off) to resume TRT.

I will also add that PSA numbers get elevated anytime you orgasm and none of the doctors I spoke to told me this (good old Google). But they did confirm it when I asked. (source)

And in all cases, the night before my blood tests after starting shots, I had been having sex. So now I wait to have sex (or masturbate) until after my blood draw so that it’s more accurate.

6 months after starting TRT

At this point, the 3-week break for the prostate scare aside, I’ve been doing TRT hormone therapy shots for almost 6 months. I started with 200mg shots which they eventually brought down to 140mg.

Now, after my most recent blood work (which the TRT office does every 3 weeks), they upped the amount of testosterone to 160mg.

Here are my current numbers:

Testing for Starting Level 6 Month Level
Testosterone 349 659
Estrogen (estradiol) 47 19 (normal range under 39)
PSA (prostate) 2.00 6.09 (ideally under 4)

So as you can see, so far my testosterone hormone levels have increased by 89% (and remember one test showed them as low as 250). But ideally, I would get my normal levels of testosterone up to around 800.

Estrogen levels (which block the effects of testosterone) have decreased by 60%, while my PSA levels have increased by 205%.

I will have follow-up checks with my urologist to keep an eye on my prostate and make sure my elevated numbers aren’t a sign of something more serious.

But for now, they do not appear to be.

Frequently Asked Common Questions

Where do they give you the TRT shots?

The TRT injection site is in the butt cheeks. They did the right cheek 1 week and the left cheek the next. This required undoing my belt and lowering my pants and underwear slightly. But I was not naked.

I assume they do the injections in the butt so they aren’t giving you needle marks in the arm.

Do TRT shots hurt?

Not any more than any other shot. It’s quick (1-2 seconds), and the needle was normal-sized.

Did you feel any side effects from TRT shots?

On my second shot, I did feel a little “off” the whole day.

But I was also fighting off a cold and it was a stressful week since my divorce was being finalized and I was shuttling 2 of my kids to multiple dental and doctor appointments.

But what I felt was a dull headache, not unlike allergy sinus headaches.

I did not feel that when I woke up the next morning. Overall, I did not feel much out of the ordinary the rest of the time, and my vitals were always good when they took them at the clinic.

How many TRT shots does it take to feel the effects?

I did not notice any noticeable changes after the first 2 shots, although I was fighting off a cold those weeks.

However, after the 3rd shot, I did begin to feel an increase in my libido and a much stronger desire to masturbate (like when I was a teenager).

By the end of the 3rd week though, I could feel my energy wane and my erections were less consistent. After the 4th shot, however, that shot up quite a bit.

I do definitely get the sense though that you need to be consistent with getting the shots every week in order to maintain the benefit. But overall, my sexual function, quality of life, and sex life have all dramatically improved and for me, outweigh the potential risks.

How much do TRT shots cost?

The place I went, Total Care Primary Care, had a monthly program for about $225/month which included all shots and a blood test every 6 weeks to monitor levels. This was the price of not using insurance.

When I asked about insurance, it sounded like it would be the same or higher, but I would have paid my co-pay per visit as opposed to $250 at the start of each month.

So I went for their monthly program price.

How do they do TRT shots if you are gone on vacation?

My clinic told me to always let them know if I was going to be gone for a week or more.

Now if you’re gone for 2 or more weeks it could be worth finding a clinic where you are going to get shots as otherwise, I would expect your testosterone levels to drop.

But for a 1-week vacation, my clinic had me get my normal shot at the start of the week and then come back on Friday for a smaller shot to make up for the missing week about to happen.

What are the symptoms of low testosterone?

Probably these are obvious which is why you Googled it and found my article. But here are the most common symptoms of ED or low-T:

  • Low sex drive (less desire to have sex)
  • Erectile dysfunction (the inability to get or maintain an erection)
  • Depression
  • Lack of focus
  • Poor memory
  • Tire easily
  • Moodiness and irritability
  • Lower muscle mass
  • Weight gain

Is TRT the same as getting anabolic steroids?

Testosterone replacement therapy (TRT) is not the same as taking anabolic steroids.

While steroids do use testosterone, the amount is different as is the end goal. TRT aims at treating the symptoms of low libido. By comparison, anabolic steroids contain significantly larger amounts of testosterone to build muscle fast and easily.

Of course, it should go without saying that you should never combine the two as it could result in dangerously high levels of testosterone.

When in doubt, talk to your doctor.

Does TRT affect your blood pressure?

My doctor checks my vitals with every shot (weekly). They check my blood pressure, oxygen levels (the finger clip device), temperature, and my weight.

I have never in my life had high blood pressure, and the TRT shots have not caused that to increase whatsoever.

However, TRT can increase estrogen (what they call estradiol) levels and increased estradiol can cause high blood pressure. Luckily, my doctor with their regular checks prescribed Anastrozole to keep my estradiol levels from increasing. Increased estradiol levels will also slow or stop the benefits of the TRT in the first place.


Can TRT cause heart disease or increase the risk of a heart attack?

The FDA states that TRT “may increase the risk of heart attack and stroke.” However, most studies like this one, have found that “higher levels of T are not associated with an increased risk of venous thrombosis or pulmonary embolism”. (source)

That same study goes on to conclude:

“There is no credible evidence at this time that testosterone therapy increases cardiovascular risk, but there is substantial evidence that it does not.”

So talk to your medical provider. If you engage in other behaviors that affect heart health (smoking, lack of exercise, poor diet), you may want to change those before starting TRT.

Are TRT shots the only option for low-T?

No. Aside from shots, they can also do testosterone pellets (which get inserted under the skin), or pills.

My doctor talked to me about the pros and cons of each, and I opted for a weekly shot. I didn’t like the idea of the pellets because they have to make an incision and insert them into the skin. But the plus of that is you only have to go in about every 4 months.

There are also patches and creams.

But for me, I can pop into my doctor’s office weekly, no appointment needed, and I’m in and out in under 5 minutes. Quick, easy, and painless.

Does TRT cause a high red blood cell count?

Testosterone replacement therapy can sometimes cause an increase in red blood cells.

For me, this has not been an issue. When men have too many red blood cells it can make the blood thicker. To be fair, my red blood cell count has gone up and my blood has gotten a little thicker.

But my levels are still within the normal tolerance. If they get too high, my doctor might prescribe a blood thinner. But so far, 6 months in, that has not been necessary. (source)

Final thoughts

Testosterone replacement therapy (TRT) is the male equivalent of hormone replacement therapy that women sometimes get around menopause. And unfortunately, testosterone deficiency is more and more common among older men.

So am I glad I started the shots?

Absolutely! For older men like myself, prostate scare aside, I have the energy of a much younger man. In the prior 14 months, I’ve dropped 39 pounds, at least 15 pounds of which happened after the TRT shots started. So for me, there are a lot of benefits of testosterone therapy.

My erections aren’t perfect.

I also got my TRT doctor to prescribe generic Viagra (initially for the 3 weeks I wasn’t on TRT, but I still take a couple of 20mg capsules sometimes). But in the past, I wasn’t able to get an erection later in the day without Viagra.

And if I was drinking alcohol, it might not happen at all, even with Viagra.

So the TRT definitely allows me to get and maintain an erection for quite some time. It also seems to have the side effect of allowing me to delay orgasm so I can go longer.

I’m glad I started and I don’t plan to stop. For me, testosterone treatment was a very good idea. Curious? The first step is to talk to a doctor today and come up with a treatment plan!

Image by JR from Pixabay

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Jeff Campbell