At What Age Do Your Breast Stop Developing?

Growth is finished at an early age but changes continue throughout your life. Weight loss/gain, genetics, pregnancy, and age can all affect your breasts over a lifetime.

Most breast growth occurs during puberty and is stable by age 16-20.  Then, pregnancies, weight gain, weight loss and hormone replacement (birth control pills, pellets, and post menopausal hormone replacement) can all influence breast growth.  Some would say that the breast keeps changing throughout life. 

Normal female breast development occurs in distinct stages throughout a woman's life. For most women breast development starts in their early teen years and stops usually by there early 20's. Breast size and shape is further influenced by pregnancy, breast feeding after child birth  and later menopause. Some women's breast can also change significantly during their monthly period. 

Your breasts will continue to change throughout your lifetime. The volume of your breast usually achieves its endpoint by 16 to 18 years old. However, your development is also depending upon your weight gain and loss and your pregnancy history. As you get much older your hormone deficiencies cause your breasts to change in a way usually associated with atrophy and sagging. Because of this, making choices for your breast enhancement is something that is best done with a board certified plastic surgeon. I can help you discuss your family history and your breast augmentation goals that you have at the time of your consultation.

Answer from Dr. Sean Hill, Board-Certified Plastic Surgeon at Lone Star Plastic Surgery – Frisco, TX:
This is a common question, especially from patients exploring breast enhancement or considering surgery.
Breast development usually begins in early adolescence — often between ages 8 and 13 — and most individuals reach full breast maturity between ages 17 and 18. That said, it’s completely normal for the breasts to continue changing subtly into your early 20s, especially with hormonal changes, weight fluctuations, pregnancy, or birth control.
Here are a few things to keep in mind: • Puberty is just the beginning: Breasts continue to evolve even after your period becomes regular. • Your unique genetics and hormones play a big role in your final size, shape, and symmetry. • Life events like pregnancy, breastfeeding, and menopause can further impact breast tissue.
If you’re considering breast augmentation or a lift, the most important thing is that your development is stable and your expectations are clear. At Lone Star Plastic Surgery, I take the time to assess not just physical development, but also your long-term goals to ensure the best possible outcome — whether that means volume restoration, reshaping, or correction of asymmetry.
If you’re unsure whether your breasts have fully developed or are a candidate for surgery, we’d be happy to walk through it together during a consultation.
Warmly,Dr. Sean Hill

For the majority, breast development is considered complete by age 18-20. During puberty, which usually begins between ages 8 and 13, the breasts start developing under the influence of hormones like estrogen. Growth can continue throughout adolescence and may slow down once a person reaches their late teens. However, breast tissue can change based on genetics, age, pregnancy, breastfeeding, and weight and hormonal fluctuations, even after the primary development phase is complete.
Krishna Vyas, MD, PhD, MHSHarvard, Hopkins, & Mayo Clinic Trained Aesthetic Plastic SurgeonNew York, New York

Breast development typically concludes around the ages of 17 to 18, marking the end of puberty. However, it's important to note that breasts can continue to change in response to factors such as weight fluctuations, hormonal changes, pregnancy, and aging, and some may notice changes into their early 20s.

Breast tissue starts developing at puberty. The breast is a hormonally active organ so breasts can always respond to changes in your estrogen levels, whether that’s due to pregnancy, child birth, breast feeding or even hormonal medication later in your life. Typically, in your 50s and 60s breast tissue involutes and becomes more fatty in texture. Breasts really develop over your lifetime. As it relates to breast growth for a breast reduction candidate, growth is typically complete once your growth plates have closed. In a young patient, often times we obtain a wrist x-ray to make sure the growth plates have closed and the patient is ready for the reduction. Breasts can also grow with weight gain and can decrease with weight loss at any age.

Typically for most women breast development is occurs during puberty and stops by age 18, however some women do experience changes after this. Most often this is in response to changes in body weight and composition which can also change during the late teens and early 20s. However the breasts do undergo significant changes during pregnancy and following pregnancy as well as menopause which can alter their size and shape.

Breasts usually stop developing by 18-21 years of age, which is why most plastic surgeons will generally recommend waiting until after that age for any cosmetic breast surgery, but you can do certain breast surgeries in younger patients. Even though the breasts are fully developed, they continue to change with age, and especially with pregnancy and breast feeding. It's important to talk to your surgeon about all these things when considering breast surgery!

this is an important questions for anyone planning breast surgery. Breast development starts at menarche and can continue to develop for anytime between 18-21 years in general. For most patients they can wait till age 21 to get any breast surgery. In some cases you can get an idea of any further breast development from family history. In such cases the patient can decide to go ahead with surgery at earlier age than 21 .