Does Testosterone Help You Grow Taller?

Testosterone triggers a dramatic growth spurt during puberty, but it does not increase final adult height. The hormone accelerates how fast bones lengthen over a period of months to years, yet the same process that drives that rapid growth also sets the timer for when growth permanently stops. The paradox comes down to estrogen: testosterone is converted into estrogen in the body, and estrogen is the signal that fuses growth plates shut. Understanding this dual role explains why testosterone can make a teenager shoot up faster without making them end up any taller than they would have been otherwise.

How Testosterone Drives the Pubertal Growth Spurt

Before puberty, children grow at a fairly steady pace of about five to six centimeters per year. When testosterone levels rise in boys, that rate roughly doubles. A study tracking boys through puberty found a strong positive correlation between morning testosterone levels and growth speed, with growth velocity increasing by about 50% once testosterone reached a relatively modest threshold.¹ That acceleration is what produces the classic teenage growth spurt, typically peaking around ages 13 to 14 in boys.

Testosterone promotes growth partly by amplifying growth hormone secretion. When testosterone enters the bloodstream, a significant portion of it gets converted into estrogen by an enzyme called aromatase. That estrogen then stimulates the pituitary gland to release more growth hormone. Testosterone also specifically increases the amount of growth hormone released in each secretory pulse, without changing how often those pulses occur.² The net result is a surge in growth hormone and its downstream partner, insulin-like growth factor 1, which together tell the cartilage cells in growth plates to multiply faster and build more bone.

Why the Growth Spurt Has a Built-In Expiration Date

The same aromatization process that boosts growth also ends it. Estrogen, produced from testosterone, gradually causes the cartilage growth plates at the ends of long bones to harden and fuse with the surrounding bone. Once those plates close, no further lengthening is possible. This is why the pubertal growth spurt is intense but temporary: rising sex hormones simultaneously accelerate growth and count down toward its finish.

The pivotal role of estrogen in this process became clear from people with rare genetic mutations. Individuals who cannot produce estrogen because of a nonfunctional aromatase gene never experience normal growth plate fusion. One reported case involved a 27-year-old man with aromatase deficiency who was still growing, with unfused growth plates visible on hand X-rays, along with bone pain and recurrent fractures from weak bones.³ Similarly, a male patient with a defective estrogen receptor continued growing well past normal age, reaching an unusually tall stature because his body could not respond to the estrogen signal to close growth plates.⁴ These cases confirm that estrogen, not testosterone itself, is the switch that shuts down longitudinal bone growth.

This distinction matters because it means testosterone’s growth-promoting effects are always paired with growth-ending effects. You cannot separate the two in a normally functioning body. More testosterone means more estrogen, which means growth plates fuse sooner.

Testosterone Therapy in Boys with Delayed Puberty

The clearest clinical evidence on testosterone and height comes from boys with constitutional delay of growth and puberty, a common condition where puberty simply starts later than average. These boys are often short for their age and distressed about it, and doctors sometimes prescribe short courses of low-dose testosterone to jumpstart their growth spurt.

The therapy works impressively for speed of growth. In one study, boys receiving testosterone saw their height velocity jump to about 8.4 centimeters per year compared with 6.1 centimeters per year in untreated boys.⁵ An earlier trial found that growth velocity shot from the 3rd percentile to above the 90th percentile during treatment.⁶ That is a striking short-term change.

But the critical finding is what happened to final height. In the same trials, predicted adult height was essentially unchanged by treatment. Boys who received testosterone grew faster for a while, but their bone age also advanced, meaning their growth plates matured more quickly. The faster growth and faster maturation roughly canceled each other out. In the trial that followed boys until they stopped growing at around age 18, their actual final height averaged 167.6 centimeters, nearly identical to their pretreatment predicted height of 168.0 centimeters.⁶ A systematic review of the broader literature confirmed this pattern: testosterone consistently produced faster short-term growth and more rapid pubertal progression, but long-term data showed no harmful effect on near-adult height when conservative, time-limited regimens were used.⁷

So testosterone therapy in this context is really about timing, not total height. It lets boys reach their genetically programmed height sooner rather than later, which can matter enormously for a self-conscious teenager, but it does not add centimeters to where they end up.

When Too Much Testosterone Backfires

If low-dose, supervised testosterone does not change final height, excess testosterone actively harms it. Precocious puberty, where sex hormones surge years before normal, causes children to grow rapidly at first but then stop growing earlier because their growth plates fuse prematurely. The result is a child who towers over classmates at age eight but ends up shorter than average as an adult.⁸ The premature secretion of sex hormones accelerates skeletal maturation and can cause early closure of growth plates, limiting final adult height.⁹

The same risk applies to adolescents who use anabolic-androgenic steroids for athletic or cosmetic reasons. These synthetic androgens flood the body with far more hormone than puberty naturally provides, and premature epiphyseal closure is a recognized consequence.¹⁰ A teenager who takes supraphysiological doses of testosterone or its derivatives to try to get bigger may inadvertently lock in a shorter adult height than they were genetically destined for. The irony is hard to miss: the very substance people associate with physical size can permanently limit it when misused during the years when bones are still growing.

Oxandrolone and the Curious Exception

Not all androgens behave identically when it comes to growth plates. Oxandrolone, a mild synthetic androgen that cannot be converted into estrogen, has shown somewhat different results in clinical trials. In one study of boys with delayed growth, oxandrolone doubled growth velocity in the first six months and sustained effective growth stimulation over a full four-year treatment period without undesirable acceleration of skeletal maturation.¹¹

A comparative trial found that while testosterone injections increased height velocity without changing predicted adult height, oxandrolone actually increased predicted adult height from an average of about 170 centimeters before therapy to about 178 centimeters two years after treatment ended.¹² The likely explanation is that because oxandrolone cannot be aromatized into estrogen, it stimulates growth without pushing growth plates toward fusion as aggressively as testosterone does. This is a genuinely different outcome from standard testosterone therapy and supports the idea that estrogen, not androgen activity per se, is the primary driver of growth plate closure.

Blocking Estrogen to Extend the Growth Window

If estrogen is what closes growth plates, researchers have naturally asked whether blocking estrogen production could extend the period of bone growth. Aromatase inhibitors do exactly that: they prevent the conversion of testosterone to estrogen, leaving testosterone’s growth-promoting effects in place while removing the signal that fuses growth plates.

In a trial of boys with delayed puberty, those who received both testosterone and the aromatase inhibitor letrozole gained a predicted 5.1 centimeters in adult height over 18 months, while boys receiving testosterone alone saw no change in predicted height.¹³ A meta-analysis of randomized trials in boys receiving growth hormone found that adding aromatase inhibitors resulted in higher growth velocity, higher predicted adult height by about 5.5 centimeters, and younger bone age compared to growth hormone alone.¹⁴

These results are intriguing, but aromatase inhibitors are not a casual treatment. Estrogen is important for bone density and metabolic health. The cases of genetic aromatase deficiency mentioned earlier show what happens when estrogen is absent long-term: bones become fragile and prone to fracture despite continued linear growth. So while the strategy of decoupling testosterone’s growth effects from estrogen’s plate-closing effects is conceptually elegant, it requires careful medical supervision and is not appropriate outside of specific clinical situations.

What Happens When Testosterone Is Absent During Puberty

Looking at the opposite end of the spectrum, when testosterone is deficient during puberty, also reveals how the hormone interacts with growth. Men with congenital hypogonadism who go untreated through their teenage years often develop what clinicians call eunuchoid proportions: disproportionately long arms and legs relative to their torso. This happens because the delayed arrival of sex hormones (and therefore delayed estrogen exposure) leaves growth plates open longer than normal, allowing limbs to keep growing well past the usual stopping point.¹⁵

These individuals are not necessarily tall in the conventional sense. They may reach above-average total height, but the proportions look unusual, and the lack of testosterone means reduced muscle mass and bone density. When hormone replacement is started at the appropriate pubertal age, more normal skeletal proportions develop, reinforcing that timely testosterone exposure, and the estrogen it generates, plays a key role in shaping the skeleton’s final form and not just its final length.

Lessons from Complete Androgen Insensitivity Syndrome

One of the most interesting natural experiments involves people with complete androgen insensitivity syndrome, where the body produces testosterone but cells cannot respond to it at all. These individuals are genetically male but develop female external characteristics because androgen signaling is entirely blocked. Despite having no functional androgen receptor activity, they reach heights that are closer to male averages than female averages, with adult height falling at about 1.2 standard deviations above the female mean.¹⁶

This suggests that testosterone’s direct action on the androgen receptor is not the main determinant of adult height. Other factors, likely including growth hormone secretion patterns, genetic background, and the conversion of testosterone to estrogen (which can still occur because aromatase functions normally in these individuals), contribute substantially to how tall someone grows. Height is not simply a testosterone story.

Testosterone Therapy in Transgender Adolescents

Transgender boys (assigned female at birth) who receive testosterone as part of gender-affirming care offer another window into how testosterone interacts with growth. These individuals typically receive puberty-suppressing medication first, followed by testosterone. A study of this population found that testosterone therapy had a neutral to positive effect on adult height, and that those who started treatment with a younger bone age tended to end up slightly taller than predicted.¹⁷ This is consistent with the broader pattern: when growth plates are still relatively immature, testosterone can drive meaningful growth before estrogen-mediated closure catches up.

Once Growth Plates Are Closed, Testosterone Cannot Reopen Them

For adults whose growth plates have already fused, testosterone has zero effect on height. No amount of testosterone, whether from supplements, injections, or any other source, can lengthen bones that have stopped growing. Growth plates are cartilage structures that, once converted to solid bone, do not regenerate. This is a permanent, irreversible change that happens by the late teens in most people, sometimes extending into the early twenties.

What testosterone does do for adult bone health is maintain density. Animal research has shown that testosterone prevents the loss of bone mineral density that occurs after the gonads are removed, preserving bone formation rates and mineral content.¹⁸ In adult humans, testosterone replacement in men with clinically low levels helps maintain bone strength and reduces fracture risk. But maintaining bone density is fundamentally different from growing taller. The bones get stronger, not longer.

Testosterone Boosters and Height Claims

A sizeable industry markets “testosterone-boosting” supplements with vague promises about physical enhancement. An analysis of popular online testosterone boosters found that among 37 human studies of the ingredients in these products, only about 30% showed any increase in testosterone levels at all. Users reported perceived improvements in energy and strength, but not a single user in the assembled consumer comments reported any improvement in height.¹⁹ Even if these supplements did raise testosterone meaningfully, the biological reality remains: in adults, no hormonal manipulation can reactivate closed growth plates, and in adolescents, added testosterone speeds up both growth and plate closure without changing the destination.

The disconnect between public perception and biological reality on this topic is wide. Testosterone is culturally associated with size, and that association is not entirely wrong when it comes to muscle mass. But for height specifically, testosterone is a timing hormone, not a quantity hormone. It determines when you grow fast and when you stop, not how tall you ultimately become. That distinction is easy to miss but essential for anyone wondering whether testosterone could add inches to their stature.