GLP-1 medicines: what they are and which are available in Spain

What does GLP-1 mean?

GLP-1 is a hormone released by the gut after eating. It contributes to feelings of fullness and to the release of insulin when blood glucose rises. Medicines that act on its receptor prolong this signal. Tirzepatide also acts on GIP, another gut hormone that responds to food [1][3].

They are often all referred to as “GLP-1 medicines”, although their mechanisms and indications are not identical. The same molecule may be sold under different brand names for different authorised uses [1][2]. The brand name alone does not tell you what it is for.

If you know several people who inject these medicines and wonder what we think, it is a question we often hear in appointments. Starting, continuing or changing a medicine requires a medical assessment. Our role is to adapt your diet and habits while you are having treatment.

The brand identifies a product; its indication and your clinical circumstances guide the conversation with your doctor.

What is each medicine authorised for?

Not all medicines for obesity or diabetes act on the GLP-1 receptor. Here we cover those that do, as well as tirzepatide, which also acts on GIP [3]. This grouping explains the mechanism; it does not rank the products by effectiveness.

Ozempic, Rybelsus and Trulicity are authorised for type 2 diabetes [1][5][6]. Wegovy and Saxenda are indicated for weight management [2][4]. Mounjaro has both indications in the European Union, each subject to its own conditions [3]. A medicine’s authorisation in Europe does not guarantee that it is available or funded in Spain.

What should you ask before starting?

Bring a list of the medicines you take to your appointment and explain what you hope to achieve with the treatment. Ask what the proposed product is authorised for, how you will be monitored and whom to contact if you develop side effects. If you have diabetes and take insulin or other medicines that lower blood glucose, make sure you mention this. Adjusting those treatments is the medical team’s responsibility.

If you have had an eating disorder, mention it before starting. It is worth discussing this with your doctor and a mental health professional.

It also helps to talk about your relationship with food. When your appetite is reduced, it can be difficult to maintain a varied diet with enough protein. At your appointment, we review your meal times, which foods you tolerate and what physical activity is feasible for you.

The summary of product characteristics for each medicine lists its side effects and the precautions your doctor will consider [1][2][3][4][5]. Someone else’s dose, or one you see on social media, is not a suitable guide for you.

Which active ingredient is behind each name?

Semaglutide is found in Ozempic, Wegovy and Rybelsus, but each product has its own indication and formulation [1][2][5]. You can read more in our semaglutide guide. For the best-known brands, see Ozempic and Wegovy.

Tirzepatide is the active ingredient in Mounjaro. It acts on GLP-1 and GIP [3]. Our tirzepatide guide explains this combination; the Mounjaro guide gives product-specific information.

Liraglutide is found in Saxenda and in products intended for diabetes. Saxenda is given as a daily injection [4]. Our liraglutide guide helps distinguish it from other molecules. Dulaglutide, the active ingredient in Trulicity, also belongs to the group used for type 2 diabetes [6].

If you are looking for nutrition support while taking a GLP-1 medicine, we can help you eat a sufficiently varied diet, work on strength and prepare for the habits you will need afterwards. Find out about our GLP-1 nutrition support programme.