The penis grows during two windows of life: fetal development and puberty. Both are driven by hormones, primarily testosterone and its more potent derivative, dihydrotestosterone (DHT). Once puberty ends, typically by the late teens or early twenties, no natural process will restart that growth. After that point, your options for changing size are limited, and most products marketed for this purpose don’t work.
How the Penis Grows During Puberty
Your body converts about 10% of its testosterone into DHT each day. During fetal development, DHT is essential for forming the penis and scrotum. During puberty, DHT drives further growth of both. This is the only period when the penis meaningfully increases in size, and it follows the same general timeline as other pubertal changes: most growth happens between ages 10 and 17, with some individuals finishing closer to 20.
Once puberty is complete, DHT no longer plays a significant role in maintaining male physiology. This is the key biological reality behind every size-related question: the growth mechanism has a built-in expiration date. No supplement, exercise, or hormone can reactivate it in adulthood.
Does Testosterone Increase Size in Adults?
It does not. A study published in Translational Andrology and Urology found only a weak association between adult testosterone levels and penile length, and the researchers explicitly stated that this “by no means suggests that exogenous testosterone or testosterone replacement therapy will increase penile length.” Testosterone therapy in adults serves other purposes, like addressing low energy or muscle loss from clinically low levels, but penis growth is not one of them. Taking testosterone when you don’t need it also carries risks, including infertility.
What the Average Actually Looks Like
A Stanford Medicine analysis compiled data from 75 studies spanning 1942 to 2021, covering 55,761 men. The current average erect length is about 6 inches, up from 4.8 inches in earlier decades of the study window. Researchers aren’t entirely sure why the average has shifted, but the point for most men reading this is straightforward: if you’re in the range of 4.5 to 6.5 inches erect, you’re well within normal. Concern about size is far more common than an actually small penis.
Supplements and Pills Don’t Work
The FDA maintains an active list of sexual enhancement products that contain dangerous hidden ingredients. Many are marketed as “all-natural” dietary supplements for male enhancement, but the agency has found them contaminated with undisclosed pharmaceutical compounds. These products “pose a serious health risk and are not guaranteed to work,” according to the FDA. They can lead to hospitalization.
No over-the-counter pill, herb, or supplement has been shown in clinical trials to increase penile size. Products that claim otherwise rely on fake reviews and social media promotion. If a supplement actually worked, it would be one of the most widely prescribed medications in history, not sold through Instagram ads.
Traction Devices: Small Gains With Big Commitments
Penile traction therapy is the one non-surgical approach with some clinical support, though results are modest. A randomized controlled trial published in the Journal of Urology found that men using a traction device after prostate surgery gained about 1.6 centimeters (roughly 0.6 inches) in stretched length over six months, compared to 0.3 centimeters in the control group.
Traditional traction devices require 2 to 9 hours of daily wear to show any benefit. A newer device used in the study achieved results with 30 minutes per day, but this was specifically tested in post-surgical patients, not healthy men seeking cosmetic gains. Whether the same results apply outside that context is unclear. The gains are also small enough that many men wouldn’t notice a meaningful difference.
Surgical Options and Their Risks
Several surgical procedures exist, but Cleveland Clinic notes that “very few methods work reliably well to increase penile size or length.” The most common options include cutting the suspensory ligament (which makes the flaccid penis hang lower but doesn’t add tissue), injecting fat harvested from elsewhere in the body to increase girth, and injecting dermal fillers under the skin.
Complications include infection, scarring, pain, loss of sensation, and erectile dysfunction. Because of these risks, many surgeons won’t perform enlargement surgery on a penis that falls within the normal size range. These procedures are generally reserved for men with a genuine medical condition, not cosmetic dissatisfaction.
Weight Loss Can Reveal Hidden Length
One of the most practical and underappreciated factors in visible penis size is the fat pad above the base of the penis. In men carrying significant extra weight, this fat can partially or fully bury the shaft, making the penis appear much shorter than it actually is. Surgical removal of this fat pad is one recognized procedure, and weight loss through diet and exercise can achieve a similar effect without surgery.
Research on men with buried penis who underwent bariatric surgery found that the ability to see their penis increased from 8% before surgery to 55% after weight loss. Results vary, and some men have residual loose skin or fat that limits improvement. Still, for men who are overweight, losing weight is likely the single most effective way to gain visible length, because the actual penis is already there.
Better Erection Quality Makes a Real Difference
A penis that’s fully engorged with blood is noticeably larger and firmer than one operating at 70% capacity. Many men who feel they’re “too small” are actually experiencing incomplete erections due to poor blood flow. Nitric oxide, a molecule your body produces naturally, is the key signal that relaxes blood vessels in the penis and allows blood to flow in. When nitric oxide production drops, erections become softer and smaller.
The factors that reduce nitric oxide are familiar: excess body fat, inactivity, smoking, poor diet, and cardiovascular disease. Improving cardiovascular fitness through regular exercise, losing weight, and quitting smoking can meaningfully improve erection quality. This won’t change the structural size of the penis, but a harder erection at full capacity looks and functions differently than a soft one. For many men, this is the actual problem they’re trying to solve.