Weight Loss Injections and Tablets

There are a variety of different weight loss treatments, such as weight loss injections and weight loss tablets, that are licensed and approved for use in Ireland.

Weight loss medications can only be prescribed at ZAVA if you have a body mass index (BMI) over 30, if you have no medical conditions or take any other medications that could interact with them.

You can also be prescribed weight loss injections if you have a BMI of 27 to 30, with one or more weight-related health conditions. Some examples of weight-related medical conditions include prediabetes, type 2 diabetes, high blood pressure, and cardiovascular disease.

Weight loss tablets containing orlistat can also be prescribed if you have a BMI between 28 and 30, with one or more weight-related conditions.

Mysimba, another weight loss tablet available at ZAVA, can be prescribed if you have a BMI between 27 and 30, and are at risk of developing a condition relating to being overweight.

These treatments work best when taken alongside a healthy diet and exercise plan, so you can lose weight effectively and safely.

Weight loss injections help you lose weight by reducing your appetite and helping you feel fuller after a meal. This means you’ll be more satisfied after a meal with fewer calories. Weight loss injections are the most effective weight loss treatment for most people, and can help you lose up to 22.5% of your starting body weight (statistic taken from a study on Mounjaro 15mg taken once a week for 72 weeks).

Weight loss injections come as pens that you inject yourself with at home, so you do not need a medical professional to inject them for you. You usually inject yourself in the stomach, thigh, or upper arm (with help) – wherever is most comfortable for you.

Tirzepatide (Mounjaro) is an injectable weight loss treatment. It contains the active ingredient tirzepatide which mimics 2 naturally occurring hormones in your body called glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). They both help your body control your appetite and how full you feel. Mounjaro helps you lose weight by reducing hunger and prolonging how satisfied you feel after a meal.

Liraglutide (Saxenda) is another injection for people to help them lose weight. It contains a different ingredient also mimicking GLP-1, called liraglutide. Like Mounjaro, Saxenda tells your brain you’re full, making it easier to eat less and lose weight with diet and exercise. It is injected once a day.

Weight loss tablets help you lose weight in one of two ways: by reducing how much fat your body absorbs from food (orlistat and Xenical) or suppressing your appetite (Mysimba). Weight loss tablets are less effective than weight loss injections according to studies, but may be a good option if you are uncomfortable with injections.

Xenical contains the active ingredient orlistat. When taken with a meal that contains fat, it attaches to the enzymes in your digestive system, called lipase. Orlistat blocks lipase from breaking down fat in your food and absorbing it. This means some of the fat from your meal will turn into waste and be eliminated from your body as stool.

Mysimba works differently than orlistat. Instead of having an effect on the digestive system, it works on the areas of your brain that control energy levels and food intake. This can reduce your appetite so that you feel fuller when you eat less. The combination of the 2 active ingredients in Mysimba can also control the pleasure you get from eating, reducing food cravings.

When you take any weight loss treatment, doctors should review your weight regularly and make sure it is working as it should. Any weight loss medication must be taken alongside a healthy diet plan and regular exercise. Here at ZAVA, we send out a doctor and in-house nutritionist weight loss support pack with your first weight loss prescription order. You can also access doctor advice for free through your patient account.

Here are some pros and cons of each treatment which may help you make up your mind.

Weight loss injections

✓ Weight loss injections have been proven in clinical trials to cause a larger percentage of weight loss, with Mounjaro users losing up to 22.5% of their weight after taking the 15mg maintenance dose for 72 weeks. Meanwhile, people using Mysimba lost an average of 8.1% of their weight after 56 weeks.

✓ Weight loss injections like Mounjaro are only taken once a week, rather than weight loss tablets like orlistat or Mysimba which are taken more than once a day. Saxenda is the exception here, as it’s also taken once a day.

✓ Weight loss injections all work by reducing your appetite, which can be helpful for people who struggle with calorie reduction and cravings. Mysimba weight loss tablets do work in a similar way while Xenical only works if you eat fat with each meal.

Weight loss tablets

✓ Not everybody is comfortable taking an injection, so tablets may be a better choice if you cannot put up with injections. However, it’s important to note that weight loss injections come in the form of a self-injectable pen much like an insulin pen, and the needles you use are small. You can also get someone to help you.

✓ Weight loss tablets usually cost less than weight loss injections. However, weight loss injections may help you lose more weight, so you may need to take tablets for longer to get the same results.

Each prescription weight loss medication works in a slightly different way, as they contain different active ingredients. Mounjaro (tirzepatide), Saxenda (liraglutide) and Mysimba all work on the brain and other organs, to reduce appetite levels and cravings, making it easier to eat less and lose weight. Xenical (orlistat) works by changing how your body digests fat.

How do weight loss injections work?

Weight loss injections work similarly because they all belong to a class of medications called glucagon-like peptide-1 (GLP-1) agonists. This means they mimic GLP-1, a naturally occurring hormone that:

• reduces appetite, helping you to eat less
• delays the emptying of your stomach, helping you to stay fuller between meals
• regulates your blood sugar levels which can help manage diabetes (if you have it) and reduces food cravings

Mounjaro also mimics a second hormone called glucose-dependent insulinotropic peptide (GIP). This is thought to enhance the effects of GLP-1 while improving how your body breaks down sugar and fat.

How do weight loss tablets work?

Xenical is a type of medication called a lipase inhibitor. This means when you eat a meal containing fat it blocks the absorption of about a third of it, and instead this is excreted from your body in your stools. It’s recommended to take orlistat 3 times a day and consume about 30% of your daily calories in the form of healthy fats, split evenly across each of these 3 meals.

Mysimba contains 2 active ingredients called naltrexone and bupropion. They are usually used to treat different conditions but when taken together work on the parts of your brain that control appetite, reducing hunger and the desire to snack.

All prescription weight loss medications that have been approved for use in Ireland are proven to help with weight loss in clinical trials. However, some weight loss medications are more effective than others.

Weight loss treatment can have side effects, just like any other medication. Not everyone will get them and if they do appear, they usually only last for a few weeks.

If you get side effects whilst taking weight loss treatment and they do not go away or bother you a lot, speak with your doctor

Some treatments are increased gradually over time, like Mounjaro, Saxenda and Mysimba, to reduce the chances of side effects.

Common Mounjaro side effects

Very common side effects of Mounjaro are:

• diarrhoea
• constipation
• feeling sick (nausea) and vomiting
• when used in combination with certain diabetes medications: low blood sugar

Side effects that affect the digestive system are usually not severe. They mostly show up after starting the treatment or after increasing the dosage – once the body gets used to the medication these side effects usually disappear.

Common Saxenda side effects

Very common side effects of Saxenda include:

• nausea
• vomiting
• diarrhoea
• constipation
• headaches

These side effects usually go away after a few days or weeks.

Common Mysimba side effects

Common Mysimba side effects include:

• hot flushes
• anxiety
• trouble sleeping
• headaches
• dizziness
• restlessness
• heart palpitations

These usually go away once your body gets used to the medication. You cannot take Mysimba if you have certain medical conditions, but our doctors will check your suitability before prescribing.

Common Xenical side effects

The most common side effects of Xenical are:

• needing to poo urgently and more frequently
• oily or fatty poo
• oily discharge from your rectum (anus)
• flatulence (farting)

Sticking to a low fat diet will decrease the risk of these side effects.

You can get some weight loss medications over the counter, but they don’t usually contain an active ingredient. That being said, you can only be prescribed weight loss medication if you meet certain conditions and some treatments cannot be taken if you take other medications or have certain health conditions.

Alongside medication, you can support your weight loss journey with options like healthy eating and regular exercise.

Surgery is sometimes considered when other weight loss methods haven’t worked and should generally be a last resort.

Diet

To lose weight at a safe pace of 0.5 to 1 kg a week, you should reduce your calorie intake by 600 kcal a day. This is not about following a ‘fad’ diet, but about making healthier long lasting choices that will improve your eating habits for the rest of your life.

For women, weight loss can be achieved by consuming no more than 1,400 calories a day. Men should be eating no more than 1,900 calories daily.

To lose weight, you should swap high-energy and unhealthy foods for healthier choices. This means lowering your intake of processed food, fast food, and sugary drinks like sodas and alcohol.

Exercise

Although a healthy and balanced diet can help you to lose weight, you also need to burn energy through regular exercise.

HSE recommends that adults do at least 2 hours and 30 minutes of moderate intensity exercise weekly. Some exercise is better than none, so if you struggle to exercise, you can increase this slowly, starting with 10 minutes a day.

Exercise has many health benefits and can reduce the risk of other illnesses that can affect your weight.

Surgery

Weight loss surgery can sometimes be used as a treatment for obesity. It is only available through the HSE depending on requirements that must be met at your local doctors, such as if you are severely obese and:

• are fit enough to have surgery
• have a BMI over 40, or between 35 and 40 and certain health conditions that weight loss could improve, such as type 2 diabetes or high blood pressure
• you have tried all other weight loss strategies but they have not achieved or maintained weight loss
• are receiving intensive management of your weight, usually through your GP

In rare cases, surgery may be recommended straight away if you have a BMI over 50.

People can’t take GLP-1 agonists like liraglutide (Saxenda) and other weight loss injections if they have existing health conditions that make them unsafe.

Weight loss injections may not be safe for:

• people taking certain medications, such as diabetes medicines (including insulin)
• pregnant or breastfeeding women