Ozempic (semaglutide): what it is for, side effects and what to eat

What Ozempic is and how it works

Ozempic contains semaglutide, a medicine that activates the receptor of an intestinal hormone called glucagon-like peptide-1 (GLP-1). When blood glucose rises, it promotes insulin release and suppresses glucagon, the hormone that raises it. It also slows stomach emptying and may reduce appetite [1].

That is why you may feel full sooner. Responses vary: some people continue to eat as usual, while others find that a familiar portion feels too large. The nutritional aim is to make sure reduced appetite does not leave out foods you need. In appointments, we review which meals fit into your day and which are being missed.

Type 2 diabetes is the authorised indication for Ozempic, always alongside diet and physical activity [1]. A varied eating pattern still matters when your glucose improves, because it supports your meals, energy and strength.

Ozempic is injected under the skin once a week [1]. Its active ingredient, semaglutide, is the same as in Wegovy and Rybelsus. To see the full range of treatments, visit GLP-1 medicines.

What is Ozempic used for?

In Spain, Ozempic is authorised for adults with inadequately controlled type 2 diabetes, as an addition to diet and exercise [1]. It may be used on its own when metformin is not appropriate, or added to other diabetes medicines [1]. This decision depends on your medical history and glucose control.

“I know lots of people who inject it; what do you think?” is a question we often hear in appointments. Your doctor decides whether you should take it. Our role begins once it has been prescribed: helping your diet continue to meet your needs during treatment.

Wegovy also contains semaglutide, but has its own indication for weight management and a different dosing schedule [2]. Sharing an active ingredient does not mean that pens or doses can be swapped. For a general comparison, see the GLP-1 treatment page.

Dose and safety: what to agree with your doctor

The Ozempic dose is increased in stages to help your stomach adjust. Treatment starts at 0.25 mg once a week for four weeks, then increases to 0.5 mg weekly [1].

If better glucose control is needed, the product information allows an increase to 1 mg and then 2 mg, with at least four weeks at each step [1]. The 2 mg presentation is authorised but is not marketed in Spain as at 26/09/2026; in practice, the dose dispensed here goes up to 1 mg. The 0.25 mg dose is only for starting treatment. Your prescriber decides how much to use and for how long, based on your glucose, side effects and other treatments.

If you already take insulin or a sulfonylurea, its dose may need to be reduced to prevent low blood sugar [1] [3]. Do not change any dose yourself or on the basis of nutrition advice. Bring a complete list of your medicines and any requested measurements to each review.

If you take warfarin or acenocoumarol (Sintrom), the product information recommends more frequent INR monitoring when starting Ozempic, because low INR values have been reported with acenocoumarol [1]. It is not expected to reduce the effect of oral contraceptives [1]. Always discuss this with your prescriber before making any changes.

Use the pen once a week, on the same day [1]. Do not count clicks or use leftover medicine to make a different dose.

If you are having a procedure or operation under general anaesthesia or deep sedation, tell the team that you use Ozempic, because slower stomach emptying increases the risk of aspiration [1]. The product information also notes a very rare risk of optic nerve damage, which may appear as sudden loss of vision; if this happens, seek advice without delay [1].

Keep up your follow-up even if your glucose improves. Previous diabetic retinopathy means your eyesight needs closer monitoring [1]. Warning signs that need prompt attention are listed below under “When to see a doctor”.

How much does Ozempic cost and who pays for it?

The reference price of Ozempic is €117.89 – €204.83. There are two pack types: pens containing 0.25, 0.5 and 1 mg (1.5 ml), and a 1 mg pen containing 3 ml with 8 needles; their prices differ, so the amount depends on which one you have been prescribed. With a prescription from Spain’s National Health System and, where required, prior authorisation, the medicine has a reduced patient contribution. What you pay depends on your circumstances—some people are exempt—and is shown when the prescription is dispensed. A price seen in a news story or on an old pack may be out of date.

Public reimbursement is restricted and requires prior authorisation. The Ministry limits it to adults with type 2 diabetes, a body mass index of 30 kg/m² or more, and combination treatment with other antidiabetic medicines [4]. It is not reimbursed as monotherapy [4].

Indication and reimbursement are separate questions. A private prescription for weight loss without diabetes does not qualify for public reimbursement. If your cover or circumstances change, ask your prescriber to check the current conditions.

To compare arrangements, see the price and reimbursement of GLP-1 treatments.

What side effects does Ozempic have?

Digestive side effects are the most common. In trials, nausea affected 17% of people taking 0.5 mg and 19.9% taking 1 mg. Diarrhoea affected 12.2% and 13.3%, and vomiting 6.4% and 8.4%, respectively [1].

Most were mild or moderate and short-lived [1]. Constipation is listed as common, meaning it affects at least 1 but fewer than 10 in every 100 people [1]. A symptom occurring around the time of an injection does not always mean the medicine caused it.

These steps may improve tolerance, but they do not replace a review of severe or persistent side effects. If you can barely drink, contact your prescriber, as dehydration can damage the kidneys [1].

When your stomach empties more slowly, a large meal may feel worse. Try a smaller portion and wait before having more. If constipation continues, we can review meal times, fibre and fluids without imposing a menu that worsens nausea.

Read more in our guidance on nausea with GLP-1 medicines and constipation with GLP-1 medicines.

What to eat while taking Ozempic

When your appetite falls, eating enough needs more attention than before. You do not need to force yourself to eat large portions. Spreading food across the day can help you include a variety without feeling unwell. A small meal might combine egg or fish, potato or bread, and a vegetable that suits you.

“I’ve been told to eat high-protein yoghurts” is a common question. We understand the reasoning: yoghurt can help when it is hard to finish a meal. But protein also comes from pulses, eggs, fish, meat, fresh cheese and plant-based options. One particular product does not replace variety across the day.

We can look at a typical day with you: what you have for breakfast, what you take to work and what you can tolerate at dinner. If you can manage only two yoghurts and little else, we can look for foods and meal times you can sustain. If symptoms stop you eating or drinking, discuss them with your doctor too.

Protein and strength exercise help protect muscle mass while you lose weight [5] [6]. The right amount varies with age, activity, kidney function and your clinical situation. That is why we do not give one target in grams for everyone here.

Eating less can also mean missing out on fruit, vegetables, pulses and grains; leaving them out for a long time can make your eating pattern less varied. If you find yourself repeating the same two or three dishes, we can look for alternatives you tolerate before considering a supplement.

On a nauseous day, toast with egg and fruit may be easier than a large breakfast. On another day, mild lentils with rice and vegetables may be enough. These are examples of meal structure; portions depend on your appetite.

What mistakes do we see in appointments?

We see three recurring situations: skipping meals because there is no hunger, replacing all food with high-protein products, and stopping strength exercise. None is solved by a list of foods you cannot eat. We look at the reason, what you tolerate and the time you realistically have to cook or exercise.

We also see people becoming afraid to eat because of nausea. Starting with small portions can help restore regular eating; if the discomfort continues, ask for a medical review. The aim is to make eating possible again without expecting every meal to make you feel unwell.

Your eating plan needs to fit your appetite while still supporting your nutrition.

Our weekly menu for people using GLP-1 medicines offers dishes and alternatives. The guide to protein, strength and muscle explains how to adapt this part of your plan.

What happens when you stop Ozempic?

Stopping treatment and planning maintenance should be agreed with the person who prescribes it. They may suggest continuing at a dose suited to your diabetes control; this plan is not decided in a nutrition appointment.

It is understandable to worry about regaining weight. In the extension of a trial, one year after semaglutide 2.4 mg and the lifestyle intervention were stopped, participants had regained about two-thirds of the weight they had lost [7].

This result relates to the dose studied for weight management and does not predict what will happen to each person taking Ozempic. Working on an eating plan you can maintain during treatment can help you prepare for the change, although it cannot guarantee that weight regain will be avoided. Read more in what happens after stopping Ozempic or Wegovy.

When it is not indicated or needs special assessment

The only formal contraindication in the European product information is an allergy to semaglutide or another ingredient in the medicine [1]. It must not be used during pregnancy or while breastfeeding. If you are planning a pregnancy, the product information says to stop it at least two months beforehand, in agreement with your doctor [1].

Ozempic is not indicated for type 1 diabetes or to treat diabetic ketoacidosis [1]. If you have had pancreatitis, the product information advises extra caution [1]. It is not recommended for people with severe gastroparesis, which means very slow stomach emptying [1].

If you have or have had an eating disorder, speak to your doctor and a mental health professional before starting. Reduced appetite may complicate an existing relationship with food that already needs care. Do not reduce this to a question of willpower.

A history of medullary thyroid cancer appears in warnings in some other countries, but not among the contraindications in the European product information [1]. Discuss any relevant history with your doctor rather than drawing conclusions from lists on the internet.

Ozempic if you live outside Spain

The indication, availability, price and reimbursement may vary by country and over time. This page describes the Spanish authorisation and reimbursement arrangements. If you live in Latin America, check your country’s product information and medicines register with your prescriber; Spanish conditions do not automatically apply elsewhere.

We can support your eating plan online in coordination with your local medical team. We need to know your prescribed schedule, other medicines and how well you tolerate meals. We do not replace prescribing or clinical follow-up in your country.