Can Weight-Loss Injections Be Used In Young People?

Weight-loss injections may be used in some adolescents following a medical assessment. However, the use of these medicines in young people is not planned solely according to age, weight or a desire to lose a few kilograms. The child’s growth, body mass index percentile, health conditions accompanying obesity, previous lifestyle interventions and the medicine’s current authorisation for the relevant age group should be considered together.

The term “young people” may cover different age groups. Young adults aged 18 years and over are assessed according to adult medicine indications, whereas paediatric conditions of use apply to children and adolescents younger than 18 years. A weight-loss injection prescribed to an adult family member should therefore not be considered safe or suitable for use by an adolescent.

Not every injection used for weight management has the same authorisation conditions for children and adolescents in Türkiye. Current product information published by the Turkish Medicines and Medical Devices Agency includes information on the use of liraglutide-containing Saxenda in adolescents aged 12 years and over, while the weight-management indication in the 2025 Wegovy product information is defined for adults. Age limits and indications may differ according to the country and product, so the current Turkish product information should always be reviewed.

How Is Obesity Assessed In Children And Adolescents?

The assessment of obesity in children and adolescents differs from that used in adults. Instead of the fixed body mass index thresholds used for adults, growth charts and body mass index percentiles based on age and sex are considered.

The American Academy of Pediatrics defines overweight in children and adolescents as a body mass index between the 85th and 95th percentiles for age and sex, and obesity as a body mass index at or above the 95th percentile. It states that pharmacological treatment may be considered in adolescents aged 12 years and over with obesity as an adjunct to lifestyle treatment, provided that current medicine indications, benefits and risks are taken into account.

A single scale measurement or the adolescent’s appearance is not sufficient for making a treatment decision. The following factors may be considered together:

• Changes in height and weight over time

• Body mass index percentile for age and sex

• Growth rate and pubertal development

• Family history of obesity, diabetes and cardiovascular disease

• Blood pressure

• Blood glucose and blood lipids

• Risk of fatty liver disease

• Symptoms of sleep apnoea

• Menstrual irregularities and signs of polycystic ovary syndrome

• Medicines being used

• Nutrition and physical activity patterns

• Mental health and eating behaviour

This assessment may also help determine whether thyroid disease, medicines, sleep problems or another health condition contributes to weight gain.

From What Age Can Weight-Loss Injections Be Used?

There is no single age limit for all weight-loss injections. The minimum age depends on the active ingredient, product authorisation, country and treatment indication.

According to current prescribing information from the U.S. Food and Drug Administration, the safety and effectiveness of semaglutide-containing Wegovy injection for weight management have been established in children and adolescents aged 12 years and over with obesity. Safety and effectiveness for this indication have not been established in children younger than 12 years.

The European Medicines Agency defines Wegovy as an adjunct to a reduced-calorie diet and increased physical activity in adolescents aged 12 years and over who have obesity according to age and sex and weigh more than 60 kilograms.

Current Turkish product information for liraglutide-containing Saxenda also includes information for adolescents aged 12 years and over. However, as the weight, body mass index and treatment-response requirements may differ between products, being older than 12 years alone is not sufficient for using the medicine.

In the February 2026 U.S. prescribing information for tirzepatide-containing Zepbound, the weight-management indication is defined for adults. The age limits for semaglutide-, liraglutide- and tirzepatide-containing medicines should therefore not be assumed to be the same.

Are Weight-Loss Injections Suitable For Every Young Person With Excess Weight?

Weight-loss injections should not be used to lose a few kilograms, rapidly change physical appearance or reach a weight goal influenced by social media. Pharmacological treatment in adolescents may be considered when obesity is assessed as a chronic health condition and the likely benefits are considered greater than the risks.

Weight-loss injections are not suitable for every adolescent who is considered overweight for their age but does not meet the criteria for obesity. For example, the European Medicines Agency limits the adolescent weight-management indication for semaglutide to obesity and states that there are insufficient data for adolescents who are only overweight.

Treatment may require more comprehensive consideration in the following circumstances:

• Meeting age- and sex-specific criteria for obesity

• Weight creating a significant health risk

• Type 2 diabetes or prediabetes

• High blood pressure

• Abnormal blood lipids

• Fatty liver disease

• Sleep apnoea

• Polycystic ovary syndrome

• Weight-related limitations in mobility

• Insufficient health improvement despite intensive lifestyle support

Starting medicine does not mean that nutrition and physical activity support have failed or are no longer necessary. In paediatric obesity care, medicines are considered in addition to family-based health behaviour and lifestyle treatment.

Which Assessments May Be Performed Before Treatment?

Before a weight-loss injection is considered, the child’s or adolescent’s general health should be assessed comprehensively. The purpose is not only to determine suitability for medicine but also to identify obesity-related health conditions and risks that may affect treatment.

Growth And Pubertal Development

Height, weight, body mass index percentile and growth rate should be compared with previous measurements. Because growth and body composition naturally change during adolescence, the assessment should not be based only on current weight.

If there is slowed height growth, delayed puberty or unexpectedly rapid weight gain, underlying hormonal and medical causes may be investigated. Growth should also be monitored during treatment.

Metabolic Health

Blood pressure, blood glucose, HbA1c, blood lipids and liver health may be assessed according to individual risks in children and adolescents with obesity. The American Academy of Pediatrics recommends fasting glucose, an oral glucose tolerance test or HbA1c for diabetes assessment, ALT for fatty liver disease and regular blood pressure measurement for hypertension.

Not every test needs to be performed in the same way for every adolescent. The testing plan should be determined by a physician according to age, family history, examination findings and existing conditions.

Nutritional Status

The adolescent’s daily intake of energy, protein, vitamins, minerals and fluids should be assessed. Unsupervised use of an appetite-reducing medicine in an adolescent who already eats inadequately, skips meals or follows a highly restrictive diet may increase the risk of muscle loss and nutritional deficiency.

Treatment should not focus solely on calorie reduction. Adequate intake of protein, calcium, iron, vitamin B12, folate and other essential nutrients is important during growth.

Mental Health And Eating Behaviour

Adolescents may experience significant anxiety about weight and physical appearance, bullying, low self-esteem, depression or symptoms of an eating disorder. Mental well-being should therefore be assessed together with physical health before treatment.

The American Academy of Pediatrics recommends a family-centred, non-stigmatising assessment for children and adolescents with obesity and regular evaluation of depressive symptoms in adolescents aged 12 years and over.

If binge-eating episodes, self-induced vomiting, excessive exercise, prolonged fasting or intense fear of weight gain are present, an assessment for an eating disorder may be needed before medicine is started.

What Is The Family’s Role In Treatment?

Weight-loss injection treatment in adolescents should not place responsibility solely on the child. Food availability at home, family meals, opportunities for physical activity, sleep routines and the language used about weight may affect the sustainability of treatment.

A supportive family approach may include:

• Avoiding criticism or shame related to the child’s weight

• Not treating the scale result as the only measure of success or failure

• Creating balanced meals for the whole family

• Monitoring medicine administration and storage

• Observing adverse effects

• Attending follow-up appointments

• Respecting the child’s privacy and participation in decisions

• Preventing the medicine from being shared with others

The child’s views about treatment should also be considered. Forcing injections, making threats about weight or comparing the child with others may be psychologically harmful.

What Are The Side Effects Of Weight-Loss Injections In Young People?

Adverse effects in adolescents may vary according to the medicine used. In the study of semaglutide in adolescents aged 12 years and over with obesity, the most commonly reported problems included nausea, vomiting, diarrhoea, abdominal pain, constipation and other gastrointestinal symptoms.

Possible adverse effects may include:

• Nausea

• Vomiting

• Diarrhoea

• Constipation

• Abdominal pain

• Indigestion and reflux

• Headache

• Fatigue

• Dizziness

• Excessive appetite suppression

• Dehydration

• Increased resting heart rate

• Gallbladder problems

• Allergic reactions

In the semaglutide study, gallstones were reported more frequently in treated adolescents than in the placebo group. Rapid weight loss itself may also increase the risk of gallstones, so symptoms such as upper-right abdominal pain, fever, jaundice or recurrent vomiting should be assessed.

If vomiting and diarrhoea cause dehydration, kidney function may be affected. A routine appointment should not be awaited if the adolescent cannot drink fluids, produces less urine or develops significant dizziness or weakness.

Can Growth And Muscle Development Be Affected?

Long-term data on weight-loss injections during adolescence are more limited than data in adults. Childhood and adolescence are periods of continued height growth, bone development, muscle gain and hormonal change. The amount of weight lost should therefore not be the only focus.

A paediatric obesity workshop supported by the U.S. National Institutes of Health identified continuing evidence gaps regarding the long-term safety of obesity medicines and their effects on growth and development in young people.

The following areas may be monitored during treatment:

• Height growth

• Weight and body mass index percentile

• Muscle strength and physical capacity

• Protein and energy intake

• Menstrual pattern

• Pubertal development

• Signs of vitamin and mineral deficiency

• School performance and everyday energy levels

The nutrition and treatment plan should be reassessed if rapid weight loss, significant muscle weakness, loss of menstrual periods, marked hair loss or persistent fatigue occurs.

How Long Are Weight-Loss Injections Used In Adolescents?

The duration of treatment is not the same for every adolescent. Treatment response, adverse effects, growth, metabolic values and sustainable health improvements should be reviewed regularly.

Some product information recommends reassessing treatment if sufficient body mass index or weight change has not occurred after a specified period. The European Medicines Agency states that semaglutide treatment in adolescents should be stopped and reassessed when sufficient body mass index reduction has not been achieved after a defined period at the maximum tolerated dose.

The dose should not be increased by the adolescent or family when the medicine does not produce the expected effect. Similarly, the medicine should not be stopped suddenly simply because the target weight appears to have been reached. Decisions to start, continue or discontinue treatment should be made by the treating physician.

Can Weight Return After The Medicine Is Stopped?

Obesity is a chronic health condition that may require long-term monitoring. When a medicine affecting appetite and fullness is stopped, hunger and eating behaviour may change again. Treatment should therefore not focus only on the period during which the medicine is used.

Before discontinuation, nutrition, physical activity, sleep, family support and the follow-up plan should be reviewed. Regaining some weight does not mean that treatment has completely failed, but a medical assessment should be obtained if rapid weight gain or previous health problems return.

What Should Young People With Pregnancy Potential Consider?

Weight-loss injections should not be used for weight reduction during pregnancy. In sexually active adolescents with pregnancy potential, pregnancy plans, contraception and possible medicine interactions should be discussed openly with a physician.

Current semaglutide prescribing information states that the medicine should be discontinued when pregnancy is recognised during weight-management treatment and stopped at least two months before a planned pregnancy.

Irregular periods do not exclude pregnancy. When pregnancy is suspected, a healthcare professional should be contacted before another dose is administered.

Can Young People Use Weight-Loss Injections Without A Doctor?

Weight-loss injections should not be used without a medical assessment. Products obtained online, through social media or from another person may have unknown contents, storage conditions and reliability.

The following practices are unsafe:

• Using a pen prescribed to a family member

• Sharing an injection with a friend

• Increasing the dose without medical advice

• Changing the dosing frequency when weight loss slows

• Using more than one GLP-1-containing medicine together

• Obtaining the medicine from a beauty centre or unauthorised person

• Continuing treatment while hiding adverse effects

A medicine pen should not be shared with another person, even when the needle is changed. The dose and administration method should only follow the plan established by the prescribing healthcare professional.

Which Symptoms Require Urgent Assessment?

A routine appointment or online consultation should not be awaited when the following symptoms occur:

• Severe and persistent abdominal pain

• Abdominal pain radiating to the back

• Recurrent or persistent vomiting

• Inability to consume fluids

• A significant reduction in urine output

• Fainting or altered consciousness

• Swelling of the face, tongue or throat

• Significant shortness of breath

• Yellowing of the skin or eyes

• Severe symptoms of hypoglycaemia

• Rapidly worsening general health

In cases of severe shortness of breath, altered consciousness, seizure, fainting or rapidly worsening general health, emergency services should be contacted or the nearest emergency department should be visited.

This content is provided for general informational purposes. The selection, initiation, dose, monitoring and discontinuation of weight-loss injections in children and adolescents require an individual medical assessment.

Plan Your Online Paediatrics Consultation With Happ Health

With the “Health Everywhere, For Everyone, Always.” approach, we believe that the use of weight-loss injections in children and adolescents should not be planned according to age and weight alone, but through a combined assessment of growth and development, metabolic health, nutrition, psychological well-being and family support.

By planning an Online Paediatrics consultation through Happ Health, you can have your child’s growth chart, weight history, existing conditions, medicines and recent test results assessed. The doctor may review the body mass index percentile for age and sex, determine which tests are required and refer the child for paediatric endocrinology, dietitian or psychologist assessment when necessary.

Preparing your child’s previous height and weight measurements, list of medicines, recent test results and any ultrasound or imaging reports before the online consultation may make the assessment easier. When a physical examination, growth and development assessment or additional testing is needed, an in-person healthcare institution may be recommended.

In cases of severe and persistent abdominal pain, recurrent vomiting, inability to consume fluids, reduced urine output, fainting, jaundice, significant shortness of breath or rapidly worsening general health, an online follow-up should not be awaited and a healthcare institution should be contacted.

References

• Turkish Medicines And Medical Devices Agency, Saxenda Summary Of Product Characteristics:
  https://www.titck.gov.tr/storage/Archive/2025/kubKtAttachments/saxendakubtemiz_10_03_2025.pdf

• Turkish Medicines And Medical Devices Agency, Wegovy Summary Of Product Characteristics:
  https://www.titck.gov.tr/storage/Archive/2025/kubKtAttachments/WEGOVY0.5KB_17_02_2025.pdf

• U.S. Food And Drug Administration, Current Wegovy Prescribing Information:
  https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/215256s033lbl.pdf

• U.S. Food And Drug Administration, Current Zepbound Prescribing Information:
  https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/217806s042lbl.pdf

• European Medicines Agency, Wegovy Product Information:
  https://www.ema.europa.eu/en/medicines/human/EPAR/wegovy

• European Medicines Agency, Saxenda Product Information:
  https://www.ema.europa.eu/en/medicines/human/EPAR/saxenda

• American Academy Of Pediatrics, Clinical Practice Guideline For The Evaluation And Treatment Of Children And Adolescents With Obesity:
  https://publications.aap.org/pediatrics/article/151/2/e2022060641/190440/Executive-Summary-Clinical-Practice-Guideline-for