Average penis size has increased in last three decades – study

Science and Health

The average length of a penis has increased by a large percentage over the last three decades, according to a new study published last week.

According to the study, which was published in the World Journal of Men’s Health, the average penis size has increased by 24% since 1942. Researchers from departments of urology and public health programs in the United States and Italy compared studies between 1942 and 2021 to better understand this phenomenon.

Led by Michael Eisenberg, MD, who works at Stanford University’s School of Medicine, his team conducted research to find key answers: Is the average penis size growing? And if so, what is causing this? Using his knowledge from his time as a urology professor in addition to practicing medicine as a male fertility and sexual function specialist, Dr. Eisenberg’s team made conclusions.

More than 75 studies were sampled over a lengthy period of time, in which measurements were gathered of erect penises across more than 55,000 men worldwide.

Banana sitting comfortably in a condom. (credit: CREATIVE COMMONS)

Can geographic location determine one’s penis size?

According to researchers, data pertaining to penis length showed variety based on one’s geographic location. However, controlled data for each region (analyzing region, subject age, and surrounding population) revealed that the average penis length increased by 24% in the last 29 years.

According to Scope, a blog produced by Stanford University’s medical programs, Eisenberg sees a cause for concern. The study intentionally set out to prove an increase in length, after realizing that plenty of studies had been conducted on sperm count and testosterone decreases, congenital birth defects surrounding the penis, the improper descending of testicles, and so on. 

“We looked at flaccid, stretched, and erect lengths and created one large database of measurements. What we found was quite different from trends in other areas of male fertility and health. Erect penile length is getting longer, from an average of 4.8 inches to 6 inches, over the past 29 years,” Eisenberg told the Scope blog in an interview.

Eisenberg’s primary cause for concern is the major growth in a relatively short period of time. 

“Any overall change in development is concerning because our reproductive system is one of the most important pieces of human biology. If we’re seeing this fast a change, it means that something powerful is happening to our bodies. We should try to confirm these findings and if confirmed, we must determine the cause of these changes,” Eisenberg added. 

So, what is it that caused this rapid growth below the belt? Researchers believe that chemical exposure from pesticides and even hygienic products could have a greater impact on genetic hormonal makeup. 

“These endocrine-disrupting chemicals — there are many — exist in our environment and our diet. As we change our body’s constitution that also affects our hormonal milieu. Chemical exposure has also been posited as a cause for boys and girls going into puberty earlier, which can affect genital development,” Eisenberg said.

Now, the researchers have their work cut out for them. Next steps, according to Eisenberg, will require looking at patterns in the reproductive health systems of females and children.

One thing is clear, though: Scientists still have more work to do before they can reach definitive conclusions.