The group of medicines that has come to the fore in weight management in recent years is GLP-1 receptor agonists; they are also known colloquially as “the weight-loss injection”.
This article explains what this group of medicines is, the framework within which it is considered, and why it requires assessment and follow-up by a physician. This is not a product recommendation; the decision on which medicine to use, at what dose and for how long is made by a physician only at the end of an examination.
What are these medicines?
GLP-1 receptor agonists are prescription-only medicinal products for human use. In Türkiye, such products are placed on the market under a marketing authorisation and are obtained only from pharmacies.
Medicines in this group were first used in the treatment of type 2 diabetes; some were subsequently also authorised for the treatment of obesity. Which use each product is authorised for varies from product to product, and this information rests with the physician who writes the prescription.
The choice of product is a medical decision and cannot be made on a web page; for this reason, no product name appears in this article.
What does the World Health Organization say?
On 1 December 2025, the World Health Organization (opens in a new tab) published a guideline on this group of medicines. The main provisions of the guideline are as follows:
- In adults, excluding pregnant women, these medicines may be used in the long-term treatment of obesity.
- The recommendation is conditional; the grounds cited are the limited long-term efficacy and safety data, the uncertainties about stopping and continuing treatment, cost, and the level of readiness of health systems.
- Medication alone does not solve the problem of obesity; it should be addressed as part of a comprehensive approach that includes healthy eating, regular physical activity and the support of health professionals.
- Structured nutrition and physical activity support may be offered to adults using these medicines.
The same body (opens in a new tab) reports that, as of 2022, 2.5 billion adults worldwide were overweight and that 890 million of them were living with obesity.
How is the decision to use them made?
The use of this group of medicines rests not on a weight target but on a medical assessment. The following are looked at together in that assessment:
- Body mass index and waist circumference measurement
- Co-existing conditions such as raised blood sugar, blood pressure, blood lipids and sleep-related complaints
- Thyroid function and hormonal assessment
- All current medication and supplements
- History of weight gain, eating pattern, intervals between meals, activity habits
- Methods tried previously and the response to them
Weight is not a diagnosis in itself. There may be an underlying clinical picture behind weight gain that needs to be assessed; thyroid dysfunction and insulin resistance are the foremost of these. Medication is not considered until this assessment has been completed.
You can read more about this process on the Weight and Metabolism Management and Insulin Resistance pages.
Why is follow-up by a physician necessary?
1. The decision on suitability is made through examination. This group of medicines is not suitable for everyone. You can read who it is not used in from Who Are GLP-1 Receptor Agonists Not Suitable For?
2. Side effects are monitored. The most frequently reported side effects relate to the gastrointestinal system: nausea, vomiting, diarrhoea or constipation, abdominal pain and loss of appetite may occur. Their severity varies from person to person and some lessen over time. Less frequent but serious conditions have also been reported; tell your physician about any new complaint that arises.
3. Interactions with other medicines are assessed. A dose adjustment may be needed, particularly in people taking blood sugar-lowering medicines; otherwise low blood sugar may occur. For this reason, a list of all your current medication and supplements is requested at the consultation.
4. Nutrition and muscle mass are monitored. Adequate protein intake, fluid intake and a regular activity routine are an inseparable part of follow-up. Otherwise, part of the weight loss may come from muscle tissue.
What should not be expected?
- These medicines do not replace an eating and activity routine. As the World Health Organization guideline explicitly puts it, medication alone is not a solution.
- Results vary from person to person. It cannot be said in advance who will respond and to what extent.
- No weight target or commitment as to duration can be given.
- What happens when the medication is stopped needs to be discussed beforehand; you can read the details in What Happens When GLP-1 Receptor Agonists Are Stopped?
How is it obtained?
These medicines are obtained only with a physician’s prescription and from a pharmacy.
The Turkish Medicines and Medical Devices Agency (opens in a new tab) is clear on this: “In our country, the only legal and safe way to obtain medicines is to buy them from pharmacies.” The same body states: “Medicines obtained over the internet, by telephone and by similar means are outside the assurance of the Ministry of Health.”
You can read more on this subject in Why Are Weight-Loss Medicines Obtained Outside the Legal Supply Chain Risky?
When should you see a physician without delay?
If you experience these symptoms during treatment, contact your physician without delay:
- Persistent vomiting with signs of fluid loss such as dry mouth, reduced urination or dizziness
- Signs of low blood sugar such as sweating, trembling, palpitations or sudden hunger
- Difficulty swallowing or a sensation of something sticking in the throat
- Swelling in the neck or hoarseness
- A change in vision
- A widespread rash, itching
In the event of severe, persistent abdominal pain, particularly pain that radiates to the back, shortness of breath, swelling of the face or tongue, altered consciousness or fainting, go directly to the emergency department.
Frequently asked questions
Can GLP-1 receptor agonists be obtained without a prescription?
No. These medicines are prescription-only and are obtained only from pharmacies. The Turkish Medicines and Medical Devices Agency states that the only legal and safe way to obtain medicines in Türkiye is through pharmacies, and that medicines obtained over the internet, by telephone and by similar means are outside the assurance of the Ministry of Health.
How overweight do you have to be to use these medicines?
A definite number cannot be given for this. The decision on suitability is made at the end of an examination, taking body mass index, waist circumference, co-existing conditions, current medication and laboratory assessment together.
Do I need to follow a diet while taking the medication?
The World Health Organization guideline states that structured nutrition and physical activity support may be offered to adults using these medicines, and underlines that medication alone is not a solution. An eating and activity routine is an inseparable part of follow-up.
Could there be another reason behind my weight?
Yes. Weight is not a diagnosis in itself; there may be an underlying clinical picture behind weight gain that needs to be assessed. Thyroid dysfunction and insulin resistance are the foremost of these, and they are assessed before medication is considered.
Is it used during pregnancy?
The World Health Organization guideline states that these treatments may be used in adults excluding pregnant women. If you are planning a pregnancy or there is a possibility that you may be pregnant, please say so at the start of the consultation.
How long is it used for?
A definite duration cannot be given in advance. The World Health Organization states that its recommendation is conditional, and that the limited long-term efficacy and safety data, together with the uncertainties about stopping and continuing treatment, are among the grounds for this. The duration is determined by the physician during follow-up.
Sources
- World Health Organization, WHO issues global guideline on the use of GLP-1 medicines in treating obesity, 1 December 2025. https://www.who.int/news/item/01-12-2025-who-issues-global-guideline-on-the-use-of-glp-1-medicines-in-treating-obesity (opens in a new tab)
- World Health Organization, Obesity and overweight fact sheet, 8 December 2025. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight (opens in a new tab)
- Ministry of Health of the Republic of Türkiye, Turkish Medicines and Medical Devices Agency, Kaçak/Sahte Ürünler. https://www.titck.gov.tr/faaliyetalanlari/denetim/kacak-sahte-urunler (opens in a new tab)
