Taking weight loss medication and what to do if you forget

Reviewed by Dr Gigi Taguri

Weight loss treatments are medications that you take to help you lose weight. Some are daily tablets, some are injections. They’re usually prescription-only treatments which you can only access after going through a consultation with a clinician. This might be online, like if you use our service, or with a weight loss specialist. 

Usually, these treatments have to be taken continuously until you reach your goal weight, so you might be wondering what happens if you forget your weight loss medication? In this article we’ll look at the key weight loss treatments in the UK, how you take them, what to do if you forget to take yours and when to take your next dose.

Weight loss medications 

It’s important to remember weight loss treatments aren’t suitable for everyone, and you have to have a certain body mass index (BMI) to qualify to take them. But if you do meet certain criteria, there are a number of licensed weight loss treatments in the UK, these include:

• Mounjaro®: a weekly injection
• Wegovy®: a weekly injection 
• Saxenda®: a daily injection  
• Xenical (or its generic version Orlistat): tablet taken three times a day 

Mounjaro®, Saxenda® and Wegovy® work by suppressing your appetite, making you eat less and feel fuller for longer. 

Xenical and Orlistat work by blocking the amount of fat your body absorbs by up to a third. The fat is then passed out with your stools.

How to take weight loss treatments 

How you take a weight loss treatment depends on the type you’re taking. 

Taking Mounjaro®

Mounjaro® is a self-administered injection which you should use on your tummy, thighs or upper arms. You should inject yourself with Mounjaro® once a week. 

You should try and take Mounjaro® the same time each week, but it can be at anytime of day. It can be useful to set alarms on your phone to help you remember. If you want to change the day of the week you take your dose, make sure there are at least three days (72 hours) between doses.

Mounjaro® dosage 

The dosage of Mounjaro® depends where you are in your course. You start on the lowest dose (2.5mg) and after four weeks your dose will increase. The dose is then increased in 2.5mg increments until the highest dose (15mg) is reached. Your prescriber should tell you to stay on each dose for four weeks before you increase.

Taking Wegovy® 

Wegovy® is a self-administered injection which you should use on your tummy, thighs or upper arms. You should inject yourself with Wegovy® once a week. 

You should try and take Wegovy® at the same time each week, but it can be at any time of the day. We’d advise setting yourself a reminder on your phone, or writing it down in your calendar, to avoid forgetting it. 

Wegovy® dosage 

The dosage of Wegovy® will depend on where you are in the course. You start on a low dose (0.25mg), and this will increase every four weeks. Then at week 17 you’ll be able to continue on a maintenance dose of 2.4mg if you’re coping well with the treatment.

Taking Saxenda® 

Saxenda® is a daily injection (or pen) which is self-administered. Generally, you’ll be advised to inject yourself in the tummy, the front of your thighs or in your upper arm. Whichever area you choose, make sure you don't inject yourself in the exact same spot each day. Change (rotate) your injection site within the area you choose with each injection to reduce your risk of getting lumps under the skin .

You should try and inject yourself around the same time each day, so choose a time that works best for you.

Saxenda®  dosage 

The Saxenda® dosage depends on where you are in your course of treatment. For the first five weeks your dose will increase weekly (this process is called titration), and then you’ll reach a ‘maintenance’ dose of 3.0mg.

After 12 weeks on the maintenance dose, depending on how much weight you’ve lost, you can continue with this dose until reaching your target weight. But if you’ve not lost enough weight after those 12 weeks, your clinician will ask you to stop the treatment.

Taking Xenical or Orlistat 

Xenical or Orlistat are taken three times a day before, during or up to an hour after each meal. This usually means having one tablet in the morning, the afternoon and evening, with breakfast lunch and dinner. 

While you’re taking Orlistat or Xenical you should be eating a well-balanced diet, with some protein and carbohydrates and a good variety of fruit and vegetables. You’ll also need to make sure you’re getting around 30% of your calories from fat. 

Xenical or Orlsitat dosage 

The dosage for Orlistat or Xenical is 120mg and this doesn’t change. You can also get a 60mg version of the treatment, this is called Alli, and it can be bought without a prescription from places like LloydsPharmacy. 

Forgetting your weight loss treatment 

If you forget to take your weight loss treatment, what you do next depends on which treatment you’re taking and how long it’s been since your last dosage.

If you’ve forgotten to inject Mounjaro® 

• If it has been four days or less since you forgot to inject Mounjaro®, use it as soon as you remember. Then, inject your next dose on its usual scheduled day.
• If it has been more than four days since you forgot to inject Mounjaro®, skip your missed dose. You can then take your next dose on its usual scheduled day.

It is important that you do not double dose to make up for a forgotten dose. The minimum time between doses is three days.

If you’ve forgotten to inject Wegovy® 

Because you inject Wegovy® weekly, you do have a lot of time to remember the treatment if you’ve forgotten it. But after a certain period of time, you will have to miss the dose. 

• If it’s been five days or less since you usually take Wegovy® take the forgotten dose as soon as possible and continue with next dose as usual on your scheduled day.
• If it’s been more than five days since you usually take Wegovy®, skip this week’s dose and resume your course of treatment as usual on the scheduled day. 
• At most, you'll have 19 days from the date of your last injection to take your next, Any longer and you'd need to restart from the lowest titration.

If you’ve forgotten to take Orlistat or Xenical tablet 

If you forget one of your Orlistat or Xenical tablets take it as soon as you remember, but only if you’ve eaten in the last hour. If you haven’t eaten in the last hour, skip that dose and take the next one as usual. Don’t take a double dose.

If you’ve missed a number of tablets, please speak to your doctor, or if you’re using our service, you can send our clinicians a message in your Patient Record. 

If you’ve forgotten a dose of Saxenda® 

If you’ve forgotten your daily dose of Saxenda®, what to do next depends on how long it’s been since you usually inject yourself. 

• If it’s within 12 hours of when you usually take Saxenda®, take the forgotten dose as soon as possible, then continue with the treatment as normal the next day.
• If more than 12 hours from when you usually take Saxenda®, skip today’s dose and resume your course of treatment as usual the following day. 
• If you miss your dose of Saxenda® for three days or more, speak to a doctor about how to restart your treatment, as the dosage might change. 

You shouldn’t take a double dose of Saxenda® or change the dosages to try and make up for the missed day. 

Taking too much treatment  

If you take too much Xenical, Orlistat, Saxenda® or Wegovy® you should speak to your doctor or a pharmacist straight away. You might need medical attention. You also might experience side effects like feeling sick or vomiting.  

References 

https://www.mounjaro.com/how-to-use-mounjaro#how-to-use  
https://www.medicines.org.uk/emc/files/pil.15484.pdf
https://www.nhs.uk/conditions/obesity/treatment/
https://www.medicines.org.uk/emc/files/pil.2592.pdf
https://www.medicines.org.uk/emc/files/pil.2313.pdf
https://www.medicines.org.uk/emc/files/pil.13799.pdf