Is Your 14- or 15-Year-Old's Growth Slowing Down? What It Means and What to Do

By Christina Gerhardt, MD, board-certified pediatric endocrinologist, LIFE Pediatric Endocrinology

When a 14- or 15-year-old's growth slows, it means one of two very different things: either puberty is finishing and growth is winding down on schedule, or the growth spurt hasn't happened yet and something may be holding it back. The way to tell them apart is not to wait. It is to look at three things together: how fast your teen has grown over the past year, how far along puberty is, and what a bone age X-ray shows about how much growth is left.

Parents usually notice it at a checkup or against the kitchen doorframe. Jeans that used to be outgrown every season still fit. Friends shot up over the summer and your child didn't. Or your daughter grew fast at 12, and now, at 14, the measurements barely move.

Sometimes that's exactly what should happen. Sometimes it's the first sign of a problem that is far easier to address now than later. The window to change adult height closes when the growth plates close, and at 14 and 15, that window is often narrower than families expect.

Signs Your Teen Is Still Growing

These signs suggest there is still meaningful height ahead:

• Measurable height gain in the last 6–12 months. Any steady upward movement on a measured chart is the most reliable sign.
• Shoe size still going up. Feet often grow early in puberty, so a recent jump in shoe size can signal the spurt is still underway.
• Puberty is early or in progress, not finished. For boys, the voice is still cracking and facial hair is sparse. For girls, the first period was recent or hasn't come yet.
• Your teen looks younger than classmates. Late maturers usually grow later and longer. That's often the pattern behind constitutional growth delay.
• A bone age younger than their actual age. This is the only sign on this list that a doctor can measure directly.

Signs Growth Is Winding Down

• Height has barely changed in a year despite good measurements.
• Puberty looks complete: a deep, settled voice, regular shaving, and an adult build in boys; periods for two or more years in girls.
• Shoe size hasn't changed in over a year.
• A bone age near adult maturity (around 15–16 in girls and 17–18 in boys, roughly where growth plates close).

None of these signs can tell you whether your teen is reaching their full potential. A teen who stops growing at 15, but at a height far below what their family genetics predict, needs an evaluation just as much as one who never started.

Is It Normal for Growth to Slow at 14 or 15?

It depends on sex and on puberty stage. Here is how we read the most common situations:

Girls typically hit peak growth around age 11 to 12 and boys around 13 to 14, about two years later. That's why a slowdown in a 14-year-old girl is usually the end of the story, while the same slowdown in a 14-year-old boy is often the middle of it — or a sign the story hasn't started.

Why a Teen's Growth Slows: The Common Causes

• Normal completion of puberty. Rising estrogen in both girls and boys gradually closes the growth plates.
• Constitutional delay of growth and puberty. A "late bloomer" pattern that often runs in families. Growth slows right before the spurt, which makes these teens fall further behind peers at exactly 13 to 15. Read more in our guide to delayed puberty in boys.
• Early puberty that finished early. A teen who matured at 10 or 11 may already be near adult height at 14. Their bone age runs ahead of their real age.
• Growth hormone deficiency. It can appear at any age, including the teen years, and often shows as a slowing growth rate.
• Thyroid problems. Hypothyroidism slows growth and often brings fatigue, weight gain, and feeling cold.
• Hidden gut or inflammatory disease. Celiac disease and Crohn's disease can slow growth before any stomach symptoms are obvious.
• Not eating enough for activity level. Common in competitive athletes, especially in sports that emphasize weight or leanness.
• Medications. Stimulant ADHD medications can reduce appetite, and long-term steroids can slow growth directly.
• Short sleep. Growth hormone is released mostly during deep sleep, and many teens average far less than they need.

For a deeper look at medical causes, see what causes a child to grow poorly in height.

Red Flags That Mean You Should Book an Evaluation Now

• Growing less than about 2 inches (5 cm) a year before puberty has clearly started.
• Dropping across two major percentile lines on the growth chart.
• No testicular enlargement by 14 in boys, no breast development by 13 in girls, or no period by 15.
• Puberty started, then stalled.
• Predicted adult height well below the family target. You can estimate your teen's target with our genetic growth potential calculator.
• Other symptoms: fatigue, unexplained weight change, headaches or vision changes, chronic stomach problems, or extreme thirst.

What to Do If Your Teen's Growth Is Slowing

1. Measure accurately. Shoes off, heels against a wall, same time of day. Write down the date.
2. Gather past measurements. Ask your pediatrician for the last several years of heights and weights. One number tells us little; the trend tells us a lot.
3. Calculate the growth rate. Inches gained over the last 12 months is the single most useful number you can bring to an appointment.
4. Note where puberty stands. Voice, body hair, and shaving for boys; breast development and the date of the first period for girls.
5. Ask for a bone age X-ray. A quick X-ray of the left hand and wrist shows how mature the skeleton is and how much growth remains. Learn why a delayed bone age isn't always good news.
6. See a pediatric endocrinologist now, not in a year. This is where we disagree with the "wait and see" approach many families are given.

Why "Wait and See" Costs Teens Height

At 14 and 15, waiting is a decision, and often an expensive one. Every treatment that can change adult height works only while growth plates are open. In a teen whose bone age is already 14 or 15, there may be one or two years left to work with. A year of watching can use up half of it.

We hear it often: a pediatrician said a son would "catch up," and by the time the family came to us, his bone age showed little growth remaining. Most late bloomers do catch up. But you can't know which teen is the late bloomer and which one has a treatable problem without looking.

How a LIFE-Trained Pediatric Endocrinologist Evaluates Slowing Growth

At LIFE, a growth evaluation is built around the full picture, not one lab:

• Growth history. We review at least the last five years of measured heights and weights to see exactly when the curve changed.
• Puberty exam and bone age. Together, these tell us how much growth is left and when it will likely end.
• Targeted labs. Thyroid function, IGF-1 (a marker of growth hormone activity), celiac screening, inflammation markers, blood counts, puberty hormones, and nutrition markers such as vitamin D and iron.
• Growth hormone testing and pituitary imaging when indicated. If growth hormone deficiency is on the table, our evaluation includes an MRI focused on the pituitary gland, since a pituitary cause can explain why a child isn't making enough growth hormone.
• Nutrition, sleep, and training load. Our physicians are trained in nutrition and treat food, sleep, and activity as part of the medical plan.

Treatment Options While Growth Plates Are Still Open

Treatment depends on the cause and on how much growth is left. The options we discuss include:

• Treating the underlying cause. Correcting low thyroid, treating celiac disease, or restoring adequate nutrition can restart growth on its own.
• Growth hormone. Growth hormone is recommended for teens with growth hormone deficiency. At LIFE, growth hormone is always part of the conversation for families with height concerns, including borderline cases just outside standard criteria. It is never automatic. We recommend it only when the evaluation supports it.
• Aromatase inhibitors for boys. Medications like anastrozole and letrozole lower estrogen, the hormone that closes growth plates, which can slow bone age and extend the growing window. Studies have shown gains in predicted adult height, though evidence for some uses is still debated. LIFE physicians have used aromatase inhibitors for more than 20 years, with quarterly labs and bone age checks throughout treatment.
• A short course of testosterone for boys with constitutional delay. This can start puberty, bring on the growth spurt, and ease the social strain of looking much younger than friends.
• Nutrition and sleep, done properly. We set a protein target of about 1 gram per pound of body weight for most growing patients, and we push for 8–10 hours of sleep. Support for open growth plates is covered in our integrative guide to keeping growth plates open.

Can a 14- or 15-Year-Old Grow Taller? What Actually Works

Yes — as long as the growth plates are open. No stretching routine, hanging exercise, or over-the-counter height supplement has been shown to add height. What works is finding and fixing anything that is holding growth back, getting enough protein, calories, and sleep, and, when appropriate, medical treatment started early enough to matter. Once growth plates close, height can't be increased with medication. That's the reason the timing of the evaluation matters more than anything else on this page.

How LIFE Helps Families

LIFE Pediatric Endocrinology is a national concierge practice focused on growth and puberty. Our physicians bring more than 50 years of combined experience, with longer visits, direct physician access, and care plans built around each family's goals. We see families in person at offices in Austin, Atlanta (Sandy Springs), Beverly Hills, Newport Beach, and Nashville (Brentwood), and by telemedicine nationwide.

If your 14- or 15-year-old's growth has slowed and you want a clear answer while there's still time to act, schedule a consultation with LIFE.

About the author: Christina Gerhardt, MD, is a board-certified pediatric endocrinologist with more than 20 years of experience caring for children and teens with growth and puberty concerns. She sees families across the West Coast, the Southwest, and nationally. Read Dr. Gerhardt's full bio.

Related reading: When do boys stop growing? · When do girls stop growing? · Puberty in boys

Frequently Asked Questions

Is it normal for a 15-year-old to stop growing?

For many girls, yes. Most girls are close to adult height two to three years after their first period. For boys, it's less common. Most boys keep growing until 16 to 18, so a 15-year-old boy who has stopped growing should have a bone age X-ray to confirm whether his growth plates are closing.

Can a 14-year-old boy stop growing?

It's uncommon but possible, usually in boys who started puberty early. More often, a 14-year-old boy whose growth has slowed hasn't hit his growth spurt yet. No testicular enlargement by 14 meets the medical definition of delayed puberty and is a reason to see a pediatric endocrinologist.

How much will my teen grow after 15?

It depends on puberty stage and bone age, not age alone. Girls typically gain about 2 to 3 inches after their first period. Boys who have just started puberty at 15 may have several inches left; boys who matured early may have very little. A bone age X-ray is the most reliable way to estimate remaining growth.

What are the signs you are done growing?

No meaningful height change for a year, puberty that looks complete, and a shoe size that has held steady. Only a bone age X-ray can confirm that the growth plates have closed.

How can I tell if my teen's growth plates are still open?

An X-ray is the only reliable way. A bone age X-ray of the left hand and wrist is quick, uses a very small dose of radiation, and is read against age standards. See our full guide on when growth plates close.

Can my teen still have a late growth spurt?

Yes, if puberty is delayed and the bone age is behind the actual age. These teens often grow later and longer than their friends. A late growth spurt should be confirmed with an evaluation, not assumed.

Do height supplements or stretching help teens grow taller?

No supplement or stretching program has been shown to increase height. Good nutrition, enough protein, and 8 to 10 hours of sleep support normal growth. Medical treatment can help only when there is a reason for it and the growth plates are still open.

When should I take my teen to a pediatric endocrinologist for slow growth?

If your teen is growing less than about 2 inches a year before puberty, is falling across percentile lines, shows no signs of puberty by 13 (girls) or 14 (boys), or is tracking well below the family's genetic target. At 14 and 15, earlier is better, because every height treatment depends on open growth plates.

References

1. Johns Hopkins Medicine. What Is a Growth Spurt During Puberty?
2. Merck Manual Professional Version. Delayed Puberty
3. Nationwide Children's Hospital, Section of Endocrinology. A Clinical Guide to Delayed Puberty
4. Timing of menarche and pubertal growth patterns using the QEPS growth model. Frontiers in Pediatrics, 2024.
5. Cleveland Clinic. Here's the Age Men Stop Growing
6. Pediatric Endocrine Society. GH Deficiency, Idiopathic Short Stature, and IGF-I Deficiency Treatment Guidelines (Hormone Research in Paediatrics, 2016)
7. Grimberg A, Allen DB. Growth Hormone Treatment for Growth Hormone Deficiency and Idiopathic Short Stature: New Guidelines Shaped by the Presence and Absence of Evidence. Current Opinion in Pediatrics, 2017.
8. Randomized trial comparing anastrozole and letrozole in pubertal boys with idiopathic short stature. Journal of the Endocrine Society, 2024.
9. Outcome analysis of aromatase inhibitor therapy to increase adult height in males with predicted short adult stature and/or rapid pubertal progress: a retrospective chart review. Journal of Pediatric Endocrinology & Metabolism (PMC).

Medical disclaimer: This article is for general educational purposes and is not medical advice. It does not replace an evaluation by a qualified physician who knows your child's history. If you have concerns about your child's growth or health, please speak with your child's doctor or schedule a consultation with a pediatric endocrinologist.