Gynecomastia is caused by a hormonal imbalance between estrogen and testosterone that leads to the growth of extra glandular breast tissue in men. When estrogen (the hormone linked to breast tissue growth) rises too high compared to testosterone, the male breast can enlarge. This shift can occur naturally during certain life stages or be triggered by medications, substances, or underlying health conditions.
Gynecomastia is the medical term for enlarged breast tissue in men and boys – it is very common and affects males of all ages. It is important to recognize this is a medical condition, not just a matter of being overweight. While excess fat can contribute to a larger chest (pseudogynecomastia), true gynecomastia involves the proliferation of glandular tissue.
Both men and women produce testosterone and estrogen, just in different amounts. In men, testosterone is dominant and helps maintain a firm, flat chest, while suppressing the effects of estrogen. Estrogen, present in much smaller amounts, stimulates breast tissue growth. Gynecomastia occurs when this balance tips – either testosterone levels drop, or estrogen levels climb.
Physiologic gynecomastia refers to breast enlargement caused by normal, natural hormonal changes throughout a man’s life. It is not caused by disease and often resolves on its own, though in many cases the tissue can persist.
Infancy: More than half of male infants are born with noticeable breast buds due to estrogen received from their mother in the womb. This is temporary and usually disappears within a few weeks to months.
Puberty: The hormonal upheaval of puberty is a very common time for gynecomastia to appear, as estrogen can temporarily run high relative to testosterone.
Aging: As men age, testosterone production declines while body fat often increases. Fat tissue contains aromatase, an enzyme that converts androgens into estrogens – tilting the balance toward gynecomastia.
During puberty, hormone levels swing dramatically, and boys may briefly produce more estrogen relative to testosterone, often around ages 12 to 14. This pubertal gynecomastia affects an estimated 30% to 60% of adolescent males, is typically bilateral, and may be tender to the touch.
For most teens, it resolves spontaneously within six months to three years as hormones even out. When tissue persists into the late teens or adulthood, it rarely goes away on its own – and if it causes significant psychological distress, a consultation can help explore options.
Gynecomastia is prevalent in men over 50. The natural decline in testosterone that begins around age 30 (andropause) means the influence of estrogen becomes more pronounced over time. Older men also tend to carry more body fat, which can convert testosterone into estrogen and further tilt the balance.
Older men are also more likely to take medications and have health conditions that add to the imbalance. Unlike pubertal gynecomastia, age-related gynecomastia is less likely to resolve on its own and often becomes a permanent cosmetic concern.
A significant number of cases are linked to certain medications, drugs, or herbal products that interfere with hormone production, block testosterone, or mimic estrogen. If your gynecomastia appeared after starting a new medication, this may be the reason.
Never stop a prescribed medication without medical guidance – a change sometimes reverses tissue growth, especially when caught early. Common classes associated with gynecomastia include:
Anti-androgens for prostate cancer: Drugs like flutamide and bicalutamide block the effects of testosterone.
5-alpha reductase inhibitors for enlarged prostate: Finasteride (Proscar, Propecia) and dutasteride (Avodart).
Heart and blood pressure medications: Spironolactone (a diuretic), digoxin, and certain calcium channel blockers (such as nifedipine).
Anti-ulcer and acid reflux medications: Cimetidine (Tagamet) is a known cause; ranitidine and omeprazole are less commonly reported.
Psychoactive medications: Anti-anxiety drugs (like diazepam), tricyclic antidepressants, and antipsychotics (like haloperidol and risperidone).
Chemotherapy agents: Certain cancer treatment drugs can disrupt hormone balance.
Some antibiotics and antifungal medications. For example, the antifungal ketoconazole and the antibiotic metronidazole have been linked to gynecomastia.
If you suspect a medication is playing a role, talk with the doctor who prescribed it first.
Anabolic steroids and testosterone supplements: Used to build muscle, these synthetic androgens can be paradoxically converted into estrogen, driving significant glandular growth that often does not go away even after stopping.
Alcohol: Chronic heavy use can damage the liver, impair hormone metabolism, and directly reduce testosterone production.
Recreational drugs: Marijuana, amphetamines, heroin, and methadone have all been associated with gynecomastia.
Cutting back may help, but tissue that has already formed often requires surgery to remove.
Some consumer products contain plant-based compounds with weak estrogenic activity. Products with lavender oil, tea tree oil, or supplements marketed for muscle or “hormone support” have been linked to breast tissue growth in some men – including cases of prepubertal gynecomastia. Reviewing everything you take, including supplements, with your provider is important.
Sometimes gynecomastia is a signpost pointing to an underlying medical problem. Ruling out these conditions protects your overall health, not just your appearance.
The endocrine system is the body’s network of hormone-producing glands, and any condition affecting them can lead to gynecomastia.
Hypogonadism: Low testosterone, whether originating in the testicles (primary) or pituitary gland (secondary), is a direct cause.
Tumors: Though rare, tumors of the testicles or adrenal glands can secrete hormones like estrogen or hCG (human chorionic gonadotropin) that stimulate breast growth and need medical attention.
Liver disease: Chronic liver failure or cirrhosis prevents the liver from breaking down estrogen, allowing it to build up in the bloodstream.
Kidney failure and dialysis: Often cause hormonal shifts that lead to gynecomastia.
Hyperthyroidism: An overactive thyroid can raise sex hormone-binding globulin (SHBG), leaving more free estrogen to act on breast tissue.
Treating the underlying disease can sometimes improve gynecomastia, though residual tissue may still require surgical correction.
Obesity is a complex factor. Fat cells produce aromatase, converting testosterone to estrogen, so significant excess weight can cause true glandular gynecomastia. Obesity is also the primary cause of pseudogynecomastia – enlargement from fatty tissue alone, with no gland growth. Many men have a mix of both.
This distinction affects treatment. Glandular tissue feels firm and rubbery and usually requires surgical removal, whereas soft fat can be addressed with high-def lipo. A physical exam by a board-certified plastic surgeon, such as Dr. Ellen Ozolins or Dr. Gregory Lakin, determines the best approach for your chest.
The causes of gynecomastia are varied – natural life changes, medications, lifestyle choices, and underlying health conditions – but the common thread is a disruption of the body’s hormonal balance. Understanding what causes gynecomastia is the first step toward addressing it. Learn more about gynecomastia or request a consultation for answers specific to you.
About the Author
Dr. Gregory Lakin
July 15, 2026
Nurse Injector
She received her Bachelor of Science in Nursing from Michigan State University and worked as an operating room nurse at Michigan Medicine for 2 years before transitioning to aesthetics. She
received her certification as a Nurse Injector, and attended further training and certification through Allergan Medical Institute. She absolutely loves being a Nurse Injector and is very passionate about
combining medicine and the creativity and artistry of aesthetics in her practice. It is extremely important to her to remain educated and up to date with the newest and best treatments and injection techniques. Her goal as an Injector is that when you sit in her chair that you feel comfortable, fully educated on your procedure, and confident and happy in your results when we are done. She loves forming connections with her patients and feels truly honored to be a part of your journey to becoming your most confident self, inside and out! She is a great listener and looks forward to creating an individualized plan to meet each of her patient’s unique goals and desires. Some of her favorite treatments include lip filler, Botox, and midface/cheek filler (but there is so much more!). When she is not injecting, you can find her trying new recipes, spending time with family, working out, gardening, or taking a long walk with her dog.
Heidi Winkler BSN, RN
Director of Nursing & Surgical Services Leadership
Heidi’s goal is to ensure every patient has a positive experience and is satisfied with the high quality of service provided by our clinical staff. Her passion as a caregiver is to impact each person’s life in a positive way.
PACU Nurse
Tonya has been a registered nurse for 15 years. She earned her BSN at the University of Michigan. Go Blue!
She started her career as a trauma RN in Detroit. She has been working as a recovery RN for the past 8 years. She loves being part of a team that makes a difference in people’s lives.
Her passions include lounging with her fur babies, family, and friends, traveling, crunching, and recycling.
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