Much of the continued interest in testosterone as a supplement comes from its ability to increase muscle mass. That muscle growth has a lot of people wondering what else testosterone can grow. Since testosterone is the primary male sex hormone, many wonder does testosterone increase penis size?

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The answer to the question is a complicated one. There have been a few studies showing testosterone to help increase the size of penises. In these select cases, the mechanism for doing so is not fully known and the result came as a welcome surprise. As we’ll visit below, however, this is not the case for everyone.

What is Testosterone?

Testosterone is the hormone that enables healthy sexual reproduction in men. It is the hormone that introduces boys to puberty and is responsible for arousal as well as numerous other human emotions and reactions. Testosterone plays a vital role in puberty but it continues in meaningful ways throughout a man’s adulthood.

Testosterone enables or regulates many elements of appearance. This is because testosterone is also the driving force behind secondary sexual characteristics. These are things like facial, armpit, and pubic hair as well as increased muscle and bone mass.

Low levels of testosterone lead to poor erections or the inability to get them at all. It also causes an inability to grow facial hair and secondary sexual characteristics. Conversely, high levels can lead to irritability and aggressive behaviour. Additionally, high levels of testosterone cause acne, oily skin, and can worsen sleep apnea for those afflicted.

The Science

There is very little science covering the topic of testosterone and penile growth. There are, however, a few studies–some of which are quite old. These studies mostly deal with Low-T and micropenis reversal through testosterone. While these have been successful studies, it’s worth noting that they are also very specific in use-case.

Low-T Reversal

This Men’s Health article goes into detail on this study which shows some interesting results. In it, a 34-year-old man was able to reverse several medical conditions through testosterone injections. When he first presented, he indicated that he had scarce body hair. He also had his penis measured and found it to be at just above micro-penis levels.

Those conducting the study discovered the relation between his low amounts of body hair and low testosterone levels. As such, the prescribed regular injections thereof. After nine months of treatment, he was able to stop the injections after a permanent reversal of all symptoms. 

Not only did his body hair grow back, but his penis also grew by over 3 inches. In addition to this, his testicular volume (previously very low) returned to normal levels.

Micropenis Reversal

One study, conducted in 1978, found that five patients were able to reverse their micropenis condition. They did this with Gonadotropin along with topical testosterone. Gonadotropin is another hormone that acts on the gonads. The average increase from topical testosterone treatment was 60% in length and 52% in girth. 

This comes with a big caveat, however. In the study, they note that the response from “postpubertal male subjects” was “minimal.” Meaning that the responses mostly recorded came from subjects still going through puberty.

This leads us to the overall question provided by the science:

Stabilize or Mobilize?

Hormones give us all kinds of signals but their main goal within our body is finding balance. Testosterone is no exception. The reason that the growth was more robust in boys going through puberty is that they had that growth yet to go. 

All science points towards penis size being something of a determinate length from birth to the end of puberty. The results provided by the micropenis studies may indicate something other than just growth. It is possible that it only enabled the potential that those individual penises had before an interruption of testosterone. That said, there’s too little information at this point to know if even that is the case.

Testosterone isn’t worthless, however. For those with low testosterone levels, having a supplementary option is a godsend. Hormones are best used for their intended purpose: balance.

Does Creatine Increase Testosterone? 

Creatine is a naturally occurring compound in our bodies that helps provide energy to muscles. Because of this, it is often used as a supplement for weight lifters as a way to replenish as they work out. 

There is some research showing that extended creatine use combined with exercise may lead to higher testosterone levels. This is likely an indirect result of heavier workouts from the creatine but the reasoning is still hazy. If it is indirect, it would point to the following flow:

  1. Creatine provides added energy to muscles
  2. Muscles used in heavier workout
  3. Testosterone levels increased from physical exercise

That said, the testosterone change may be more straightforward than that. Like the rest of the article, we simply do not have enough information yet.

Charlie Penwarden

Former mental health nurse turned consultant with a critical focus on human behaviour research analysis and the optimisation of mental health management to prevent illness and promote life harmony.