What are the treatments for symptoms in Klinefelter syndrome (KS)?

It’s important to remember that because symptoms can be mild, many males with KS are never diagnosed or treated.1

The earlier in life that KS symptoms are recognized and treated, the more likely it is that the symptoms can be reduced or eliminated.2 It is especially helpful to begin treatment by early puberty. Puberty is a time of rapid physical and psychological change, and treatment then can successfully limit symptoms. However, treatment can bring benefits at any age.

The type of treatment needed depends on the type of symptoms being treated.

Treatment for Low Testosterone3

About half of males with XXY chromosomes have low testosterone levels.4 These levels can be raised by taking supplemental testosterone. Testosterone treatment can:

  • Improve muscle mass
  • Deepen the voice
  • Promote growth of facial and body hair
  • Help the reproductive organs to mature
  • Build and maintain bone strength and help prevent osteoporosis in later years
  • Produce a more masculine appearance, which can also help relieve anxiety and depression
  • Increase focus and attention

There are various ways to take testosterone:

  • Injections or shots every 2 to 3 weeks
  • Pills
  • Through the skin, also called transdermal; current methods include wearing a testosterone patch or rubbing testosterone gel on the skin.

Males taking testosterone treatment should work closely with an endocrinologist, a doctor who specializes in hormones and their functions, to ensure the best outcome from testosterone therapy. For information on how to find an endocrinologist, visit the Resources and Publications section.

Is testosterone therapy right for every XXY male?

Not all males with XXY condition benefit from testosterone therapy.

For males whose testosterone level is low to normal, the benefits of taking testosterone are less clear than for those whose testosterone level is very low. Side effects, although generally mild, can include acne, skin rashes from patches or gels, breathing problems (especially during sleep), and higher risk of an enlarged prostate gland or prostate cancer in older age. In addition, testosterone supplementation will not increase testicular size, decrease breast growth, or correct infertility.

Although the majority of boys with KS grow up to live as men, some develop atypical gender identities. For them, supplemental testosterone may not be suitable. Gender identity should be discussed with health care specialists before starting treatment.5

Treatment for Enlarged Breasts

No approved drug treatment exists for this condition of overdeveloped breast tissue, termed gynecomastia. Some health care providers recommend surgery—called mastectomy —to remove or reduce the breasts of XXY males.

When men have breasts, they are at higher risk for breast cancer than other men and need to be checked for this condition regularly. The mastectomy lowers the risk of cancer and can reduce the social stress associated with XXY males having enlarged breasts.

Because it is a surgical procedure, mastectomy carries a variety of risks. XXY males who are thinking about mastectomy should discuss all the risks and benefits with their health care provider.

Treatment for Infertility

Between 95% and 99% of XXY men are infertile, because they do not produce enough sperm to fertilize an egg naturally. But sperm are found in more than 50% of men with KS.6

Advances in assistive reproductive technology (ART) have made it possible for some men with KS to conceive. One type of ART, called testicular sperm extraction with intracytoplasmic sperm injection (TESE-ICSI), has shown success for XXY males. For this procedure, a surgeon removes sperm from the testes and places one sperm into an egg.

Like all ART, TESE-ICSI carries both risks and benefits. For instance, the resulting child might have the XXY condition. In addition, the procedure is expensive and often not covered by health insurance plans. Importantly, there is no guarantee the procedure will work.

Recent studies suggest that collecting sperm from adolescent XXY males and freezing the sperm until later might result in more pregnancies during subsequent fertility treatments.7,8 This is because although XXY males may make some healthy sperm during puberty, it becomes more difficult as they leave adolescence and enter adulthood.

Some, but not all, children with KS have language development and learning delays. They might be slow to learn to talk, read, and write, and they might have difficulty processing what they hear. But various interventions, such as speech therapy and educational assistance, can help to reduce and even eliminate these difficulties. The earlier treatment begins, the better the outcomes.

Parents might need to bring these types of problems to the teacher’s attention. Because these boys can be quiet and cooperative in the classroom, teachers may not notice the need for help.

Boys and men with KS can benefit by visiting therapists who are experts in areas such as coordination, social skills, and coping. XXY males might benefit from any or all of the following:

  • Physical therapists design activities and exercises to build motor skills and strength and to improve muscle control, posture, and balance.
  • Occupational therapists help build skills needed for daily functioning, such as social and play skills, interaction and conversation skills, and job or career skills that match interests and abilities.
  • Behavioral therapists help with specific social skills, such as asking other kids to play and starting conversations. They can also teach productive ways of handling frustration, shyness, anger, and other emotions that can arise from feeling “different.”
  • Mental health therapists or counselors help males with KS find ways to cope with feelings of sadness, depression, self-doubt, and low self-esteem. They can also help with substance use problems. These professionals can also help families deal with the emotions of having a son with KS.
  • Family therapists provide counseling to a man with KS, his spouse, partner, or family. They can help identify relationship problems and help patients develop communication skills and understand other people’s needs.

Parents of XXY males have also mentioned that taking part in physical activities at low-key levels, such as karate, swimming, tennis, and golf, were helpful in improving motor skills, coordination, and confidence.

With regard to education, some boys with KS will qualify to receive state-sponsored special needs services to address their developmental and learning symptoms. But because these symptoms may be mild, many XXY males will not be eligible for these services. Families can contact a local school district official or special education coordinator to learn more about whether XXY males can receive the following free services:

  • The Early Intervention Program for Infants and Toddlers with Disabilities is required by two national laws: the Individuals with Disabilities Education Improvement Act (IDEIA) and the Individuals with Disabilities Education Act (IDEA). Every state operates special programs for children from birth to age 3, helping them develop in areas such as behavior, communication, and social play.
  • An Individualized Education Plan (IEP) for school is created and administered by a team of people, starting with parents and including teachers and school psychologists. The team works together to design an IEP with specific academic, communication, motor, learning, functional, and socialization goals, based on the child’s educational needs and specific symptoms.

Many of the professionals and methods for treating learning and language symptoms of the XXY condition are similar to or the same as the ones used to address social and behavioral symptoms.

For instance, boys with KS may need help with social skills and interacting in groups. Occupational or behavioral therapists might be able to assist with these skills. Some school districts and health centers might also offer these types of skill-building programs or classes.

In adolescence, symptoms such as lack of body hair could make XXY males uncomfortable in school or other social settings, and this discomfort can lead to depression, substance use, and behavioral problems or “acting out.” They might also have questions about their masculinity or gender identity.9 In these instances, consulting a psychologist, counselor, or psychiatrist may be helpful.

Contrary to research results released decades ago, current research shows that XXY males are no more likely than other males to have serious psychiatric disorders or to get into trouble with the law.10


  1. Bojesen, A., Juul S., & Gravholt, C.H. (2003). Prenatal and postnatal prevalence of Klinefelter syndrome: A national registry study. Journal of Clinical Endocrinology & Metabolism, 88(2), 622-626.
  2. Dawson, 1997; Hurth, 1999; Rogers, 1989; Hoyson, 1984; Lovaas, 1987; Harris, 1991; McEachin, 1993; Greenspan, 1997; Smith, 1997; and Smith, 1998. As cited in Committee on Children with Disabilities, American Academy of Pediatrics. (2001). The pediatrician's role in the diagnosis and management of autistic spectrum disorder in children. Pediatrics, 107(5), 1221-1226.
  3. Matsumoto, A. M., Davidge-Pitts, C., Cunningham, G., Vogiatzi, M. G., & Yialamas, M. (2022 ). Hypogonadism in men. Endocrine Society. Retrieved December 20, 2023, from https://www.endocrine.org/patient-engagement/endocrine-library/hypogonadism external link
  4. Okada, H., Fujioka, H., Tatsumi, N., Kanzaki, M., Okuda, Y., Fujisawa, M., et al. (1999). Klinefelter's syndrome in the male infertility clinic. Human Reproduction, 14(4), 946-952.
  5. Herlihy, A. S., & Gillam, L. (2011). Thinking outside the square: Considering gender in Klinefelter syndrome and 47,XXY. International Journal of Andrology, 34(5 Pt 2), e348-e34.
  6. Paduch, D.A., Fine, R.G., Bolyakov, A., & Kiper, J. (2008). New concepts in Klinefelter syndrome. Current Opinion in Urology, 18(6), 621-627.
  7. Plotton, I., Brosse, A., Group Fertipreserve, & Lejeune, H. (2011). Infertility treatment in Klinefelter syndrome. Gynécologie, obstétrique & fertilité, 39(9), 529-532. French.
  8. Plotton I., Brosse A., & Lejeune, H. (2010). Is it useful to modify the care of Klinefelter's syndrome to improve the chances of paternity? Annales d'endocrinologie (Paris), 71(6), 494-504. French.
  9. Simpson, J.L., de la Cruz, F., Swerdloff, R.S., Samanga-Sprouse, C., Skakkebaek, N.E., Graham, J.M. Jr., et al. (2003). Klinefelter syndrome: Expanding the phenotype and identifying new research directions. Genetics in Medicine, 5(6), 460-468.
  10. Ratcliffe, S. (1999). Long-term outcome in children of sex chromosome abnormalities. Archives of Diseases in Children, 80(2), 192-195.
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