Contraindications and situations in which injectable treatment is not indicated

The absolute contraindications common to the class are hypersensitivity to the active substance or to any of the excipients and, for products containing semaglutide and tirzepatide, a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2. Pregnancy and breastfeeding are situations in which these medicines are not given. Separate from contraindications are the special warnings — situations that do not rule out treatment but call for assessment and monitoring.

The difference between these two categories is the most useful piece of information in this article, and the one most often missed.

Contraindication or warning — what is the difference?

A contraindication means that the medicine is not given. It is not a matter of weighing risk against benefit; it is a categorical position of the authorisation document.

A special warning means that the medicine can be given, but with prior assessment, with monitoring or with extra caution. The decision belongs to the prescribing doctor, according to the specific situation.

Confusing the two produces two symmetrical errors: people who rule themselves out even though they would be candidates, and people who ignore a situation that genuinely calls for attention. Neither is resolved by reading an article — both are resolved at the consultation.

What is contraindicated?

According to the product information published by the European Medicines Agency for Mounjaro, Ozempic and Wegovy:

• hypersensitivity to the active substance or to any of the excipients;
• a personal or family history of medullary thyroid carcinoma;
• multiple endocrine neoplasia syndrome type 2 (MEN 2);
• pregnancy and breastfeeding — these medicines are not given during pregnancy, and for people who could become pregnant, contraception and the interval for stopping before a planned pregnancy are discussed.

The documents for each product differ in the details, and the authorised version for the product someone actually has in hand is the only one that counts. That is what the leaflet in the box and the pages above are for.

What calls for caution and assessment?

These situations do not automatically rule out treatment, but they change the conversation:

• a history of acute pancreatitis — the class is associated with a risk of pancreatitis, and a previous episode changes the risk–benefit balance;
• severe gastrointestinal conditions, including gastroparesis — the medicine's mechanism slows the emptying of the stomach, which can worsen a pre-existing motility disorder;
• diabetic retinopathy, in people with diabetes — a rapid fall in blood glucose may be associated with a temporary worsening;
• concomitant treatment with insulin or sulphonylureas — the risk of hypoglycaemia increases, and the regimen of the other medicines may need adjusting;
• kidney disease — dehydration caused by digestive side effects can affect kidney function, and the product information for Ozempic contains a specific warning to this effect;
• a history of gallbladder disorders;
• older age, where digestive tolerability and the risk of dehydration call for closer follow-up.

What links them all: they are information the doctor has from your history and test results, not things established by how you feel.

Which interactions matter?

The mechanism that helps with weight loss — slowing the emptying of the stomach — has a direct consequence: it can change the speed at which other medicines taken by mouth are absorbed. For most of them this has no clinical relevance, but for those with a narrow therapeutic range it is a different matter.

The situations that come up most often in practice:

• insulin and sulphonylureas — increased risk of hypoglycaemia; the regimen of the other medicines may need adjusting, which is done by the doctor;
• medicines with a narrow therapeutic range taken by mouth — the timing of administration may matter;
• oral contraceptives — for some products in the class there are specific recommendations related to the dose-increase period;
• oral anticoagulants, where any change in absorption is worth flagging to your treating doctor.

The practical rule, the only one: the prescribing doctor must have the complete list of your medication, including supplements. They are not left out "because they are natural".

How do I find out whether I am a candidate?

Through a consultation, and with the right questions. What is worth asking directly:

Given my history, is there any absolute contraindication?

Which of the situations under special warnings apply to me?

What tests are needed before starting?

How does it interact with the medicines I already take?

What is monitored along the way, and at what interval?

What do I do if a side effect appears between two consultations?

If the answer to any of them is "it doesn't matter", a second opinion is worthwhile. Each of the six has a concrete answer.

Why is nothing on this list self-assessed?

Because each item needs context. "A family history of medullary thyroid carcinoma" means something precise, not "someone in the family had a thyroid problem". "A severe gastrointestinal condition" is not the same as "I have a sensitive stomach". And interactions with the rest of your medication are exactly the kind of information nobody assesses correctly on their own.

There is also an information asymmetry that is hard to overcome alone: an absolute contraindication can be recognised from a list, but a special warning calls for clinical judgement — how severe the condition is, what alternatives exist, what weighs more in your specific situation. That is not read; it is assessed.

There is one more reason, a less comfortable one: the same medicines can also be obtained outside the medical system, and there nobody goes through this list. We do not discuss sources of supply and we do not publish pharmacy prices — but we say clearly that the list above is the only thing standing between an appropriate treatment and an inappropriate one.

What does this mean for Synerva's services?

We do not prescribe, dispense or recommend prescription medicines. The injectable treatment remains entirely in the care of the treating doctor who prescribed it.

What we do, for people already on treatment, is an intravenous intake of fluids, electrolytes and micronutrients, during periods when oral intake is low — after our own medical assessment, with our own list of contraindications, which is different from that of the medicine. It does not treat and does not relieve the side effects of the injectable treatment.

In short

• The contraindications common to the class are hypersensitivity to the active substance and, for semaglutide and tirzepatide, a history of medullary thyroid carcinoma or MEN 2 syndrome.
• Pregnancy and breastfeeding are situations in which these medicines are not given.
• A contraindication means the medicine is not given; a special warning means it can be given, but with assessment and monitoring.
• A history of pancreatitis, gastroparesis, diabetic retinopathy, kidney disease and concomitant treatment with insulin or sulphonylureas call for caution and individual assessment.
• None of these situations is self-assessed: they are established by the prescribing doctor, on the basis of your history, test results and current medication.
• Slower emptying of the stomach can change the absorption of other medicines taken by mouth, which matters especially for those with a narrow therapeutic range.

This article is for information only and does not replace a medical consultation. Eligibility for injectable treatment is established solely by the prescribing doctor. Synerva does not prescribe or dispense prescription medicines.