'Grower' vs. 'Shower': Study Identifies Differences in Penis Erections

What does it mean to be a “grower” versus a “shower”? Researchers have now pinned down a definition in order to put penises into one of two categories—and the findings have the potential to go beyond a label.

The findings of the new study, presented earlier this month at the European Association of Urology (EAU) Congress in Milan, determined a scientific definition for whether a person’s penis can be deemed a “grower” (when it significantly increases in size when erect compared to being flaccid) or a “shower” (when it comparatively does not increase in size that much). The research also identified average lengths of both flaccid and erect penises in study participants.

For people with penises, this new research may not only offer some relief regarding average sizes, but it may also be able to help doctors make surgical decisions.

"It is important to be able to predict if a patient is a grower or a shower as when we see them, they are usually in a flaccid state,” lead researcher Manuel Alonso-Isa, MD, a urologist at the University Hospital HM Puerta del Sur in Madrid, Spain, said in a news release. “If they grow a lot when they get an erection, it might mean they need a different surgical approach compared to someone who doesn’t grow much.”

Here’s what to know about how researchers determined who can be considered a “grower” compared to a “shower” and how the findings may impact male health outcomes.

Measurements That Indicate a "Grower" vs. a "Shower"

For the study, which has not yet been published or peer-reviewed, Dr. Alonso-Isa and team conducted ultrasound scans on 225 penises in flaccid and erect states, across three hospitals and a clinic in Madrid, Spain.

The goal was to find factors among the male participants that predicted if they were “growers” or “showers”—information that could be used to make surgical decisions.

Researchers determined that if a person’s penis increased in size by more than 56% when going from a flaccid to erect state, they could be considered a “grower”; when the penis increased in size by less than 36%, the person was considered a “shower.”

Most male participants, however, didn’t fall into either category: only 24% could be classified as “growers” and another 25% were considered “showers.” Researchers also found no correlations between age, weight, smoking status, or co-morbidities and penis growth.

In addition to determining certain parameters for “growers” vs. “showers,” researchers also found that people who were “showers” tended to have longer penises when flaccid, compared to “growers.” (“Shower” penises were an average of 11.3 centimeters or 4.4 inches when flaccid, compared to “grower” penises, which were 8.8 centimeters or 3.5 inches).

Overall, the average erect penis length was 14.37 centimeters or 5.7 inches, Dr. Alonso-Isa told Health.

Other findings involved the tunica albuginea, or the spongy erectile tissue inside the penis. Though the size of that tissue didn’t influence growth, it did become thinner in erect penises in men who were considered “growers.”

“This makes sense as the tissue is being stretched further,” Dr. Alonso-Isa said in the news release. “So it could be that this tissue has more elastic fibers in men who are growers than those who are showers. But we need to do more research to prove this hypothesis.”

Potential Implications for Male Health

According to Dr. Alonso-Isa, the study’s findings can help both dissuade patients from seeking penile enhancement surgery and dictate the correct approach if they do proceed with surgical options, whether for enhancement or to correct some part of the penis’ anatomy.

“It is important to know and explain to patients what is a normal-sized penis, a small but functional penis and a non-functional micropenis, in order to adapt the treatment and adjust expectations before performing surgery or not,” Dr. Alonso-Isa said.

This information can be important, as Dr. Alonso-Isa noted an increase in patients having concerns about the size of their penis—even if they fall into what’s considered a “normal” size range. “Cosmetic penile surgeries are increasing in numbers year by year and recently several new surgical techniques have been developed to try to increase penis length in both length and girth,” he said.

The findings can also offer people a sense of relief in thinking about their penis size. “This is so important for the sexual health of men so they can feel ‘normal,’” Debra Laino, DHS, a board-certified relationship therapist, sex educator, and author, told Health.

Intrusive thoughts—not only surrounding penis size but also premature ejaculation or erectile dysfunction—can “have a big impact on men’s mental health,” Laino said. “Normalizing diversity in size as well as the many ways to have sex and be sexual with one another is so important.”