Knowing when puberty has ended can be tricky. Puberty is the process of physical changes through which a child’s body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads and involves a great deal of individual variation in timing and duration. There are no definite markers for when puberty begins or ends, but there are several signs that indicate puberty is coming to an end.
The stages of puberty
Puberty can be divided into 5 main stages:
- Prepubescence – The early stage before physical changes begin
- Thelarche – Breast development begins
- Adrenarche – Growth of pubic/underarm hair induced by adrenal androgens
- Gonadarche – Estrogen and testosterone secretion increases leading to further development
- Completion – Final adult stature and characteristics are attained
The entire pubertal process usually takes about 4 years. On average, puberty begins between ages 8-13 in girls and ages 9-14 in boys. Puberty ends by around age 14-17 in girls and 15-18 in boys. However, puberty can occur over a wide range of ages and some individuals complete puberty either earlier or later than the average.
Signs that puberty is ending in girls
Menstruation and ovulation
One of the clearest signs puberty is coming to an end in girls is when their menstrual cycles become regular.
- Menstruation (monthly bleeding) usually begins 2-2.5 years after breast development starts. The initial period is followed by highly irregular cycles for the first 1-2 years.
- Eventually, menstrual cycles become more predictable and occur every 28-35 days. This indicates the ovaries have begun ovulating regularly and releasing mature eggs.
Regular ovulation is a hallmark of completing puberty in girls.
Breast development plateaus
Breast growth starts during early puberty but continues over several years. Breasts reach their final, mature size around 1-2 years after a girl gets her first period. Breast shape and volume also stabilize. When breast development plateaus, it indicates puberty is likely finished.
Pubic and underarm hair growth completes
Pubic and underarm hair continues to spread and thicken for several years after initial growth during puberty. Completion of hair growth signals the end of pubertal development.
Adult height reached
Growth in height accelerates during puberty but slows down as estrogen levels increase. Most girls reach their final adult height soon after getting their periods. Reaching one’s genetically predetermined height is a late marker of puberty completion.
Hormone levels stabilize
Rising estrogen levels are responsible for most female pubertal changes. When estrogen levels plateau at adult levels, it indicates puberty is concluding. Blood estrogen levels can be measured by a doctor to help determine pubertal status.
Signs that puberty is ending in boys
Voice changes complete
One of the most noticeable changes in male puberty is deepening of the voice. The larynx grows under the influence of testosterone. Voice deepening usually spans 1-2 years and completes by around age 15. Stabilization of vocal pitch signals the end of the pubertal voice transformation.
Facial hair continues growing
Male faces become covered in terminal (thick, pigmented) hair as puberty progresses. The amount of facial hair steadily increases after initial growth during puberty. Maximum facial hair growth indicates the end of pubertal development.
Testicles and penis reach adult size
Testicular volume and penile length begin increasing early in puberty. Testicles reach maximal volume (15-25ml) by ages 15-16. Penises achieve adult size by age 17. Plateaus in testicular and penile growth indicate puberty is concluding.
Muscle mass and strength increases
Rising testosterone levels cause muscle tissue enlargement during male puberty. Muscle mass and strength continue increasing into the 20s due to the anabolic effects of testosterone. Peak muscle development represents the end of male pubertal growth.
Emissions become possible
Sperm production begins during puberty enabling ejaculation. Some boys experience initial ejaculations (known as emissions) spontaneously during sleep. The ability to ejaculate signals testicular maturation and the end of puberty.
Growth in height slows and stops
A growth spurt occurs early in male puberty as testosterone levels rise. Growth velocity slows as estrogen levels also increase. Most boys reach final adult height around age 18. Attaining one’s maximum genetically predetermined height indicates puberty is complete.
Adult hormone levels
At the end of puberty, the testes produce normal adult levels of testosterone and estrogen production increases as well. Stabilization of male sex hormone levels marks the end of pubertal development.
Tools to evaluate pubertal status
Since puberty involves a complex sequence of gradual changes, doctors use various methods to objectively evaluate pubertal stage in teens:
Tanner staging
This well-established 5-stage classification system is used to judge physical development based on external primary and secondary sex characteristics. It was developed by British pediatrician Dr. James Tanner.
| Stage | Girls | Boys |
|---|---|---|
| 1 | No breast development. Prepubertal. | No testicular enlargement. Prepubertal. |
| 2 | Breast bud stage. Areola widens. | Testicular volume increased. Scrotum thins and reddens. |
| 3 | Further breast and areola enlargement. No separation of their contours. | Testicles and scrotum larger. Penis length increases. |
| 4 | Areola and breast contour separation evident. | Increased testicular volume and penis size. Glans penis tip development. |
| 5 | Mature adult breast volume and projection is reached. | Testes and genitals reach adult proportions. |
Tanner stage 5 indicates full sexual maturity and completion of puberty.
Height and growth velocity
Tracking growth in height on a growth curve allows prediction of final adult stature based on slowing linear growth velocity and approach to peak height. Nearing maximal genetic height predicts the end of the adolescent growth spurt.
Sex steroid levels
Blood levels of testosterone in boys and estradiol in girls indicate gonadal maturation. Reaching normal adult ranges denotes the conclusion of pubertal hormonal changes.
Pelvic ultrasound in girls
Pelvic ultrasound can visualize uterine and ovarian size and development. Detecting a uterus comparable to an adult woman’s size and visualization of mature ovarian follicles indicates puberty is complete.
Semen analysis in boys
Semen collection after ejaculation allows analysis of sperm number, shape, movement, and volume. Presence of normal sperm and semen volume indicates spermatogenesis has been established and puberty is concluded.
Challenges determining pubertal completion
There are certain limitations involved when trying to precisely determine if an adolescent has finished undergoing pubertal development:
- There is significant individual variability in pubertal timing and progression rates among teens.
- The sequence of pubertal changes does not occur simultaneously or uniformly.
- Final stages of pubertal maturation often proceed slowly and gradually.
- Precise hormonal levels that indicate puberty is complete have not been established.
- Pubertal growth and development remains somewhat unpredictable.
- The beginning and end of puberty are transitions without definite demarcations.
Due to this inherent variability and gradual nature of pubertal maturation, determining precisely when an individual has completed puberty can be challenging. There is no clearly identifiable pubertal endpoint that can be generalized across all adolescents.
Conclusion
In summary, puberty is a complex biological process of sexual maturation rather than an acute event. There are a variety of physical milestones, developmental trajectories, and clinical assessments that can provide evidence a teenage girl or boy has likely progressed through puberty into adulthood. However, the limitations around individual differences in growth and timing prevent defining any single definitive marker. The end of puberty is best understood as a stage of stabilization when all the hallmarks of full reproductive maturity have been attained rather than a distinct threshold occasion. Careful tracking of physical changes and clinical parameters relative to the range of normal development can help identify when an adolescent appears to have completed puberty with reasonable certainty. But establishing the conclusion of pubertal maturation remains a challenging determination.