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You can highlight a preferred treatment, dose or amount to our prescriber, but to ensure your safety the final decision on any treatment you are offered is always the prescriber's. After your consultation, our prescriber may suggest a different treatment, or dose or amount of treatment (or not recommend treatment at all).Please note: this service is not to be used in an emergency. Call 999 if you need urgent medical attention.
Mysimba is an effective treatment for weight loss. It is for use alongside a calorie controlled diet and exercise.
You can buy Mysimba online using our private prescription service. Take our questionnaire to start your consultation.
Mysimba is a weight loss drug that was developed in the US by Orexigen Therapeutics and the US version of this pill is known by the brand name Contrave. Mysimba was granted a license for the treatment of weight loss in 2017. It is a prolonged release tablet, taken once a day for the first week, then this dose gradually increased during the first 4 weeks of treatment.
How much of a problem is obesity?
In the UK, over a quarter of adults are thought to be obese; and over two thirds are thought to be overweight.
The body mass index (BMI) formula is used to calculate whether or not someone is underweight, a healthy weight, overweight, or obese.
Using metric units, it is calculated by taking a person’s weight in kilograms, and dividing this by their height in metres squared.
It can also be calculated using imperial measurements, by taking someone’s weight in pounds, dividing this by their height in inches squared; and multiplying the total by 703.
If a person’s BMI is:
- less than 18.5, they are considered underweight
- between 18.5 and 25, they are considered a healthy weight
- over 25, they are considered overweight
- over 30, they are considered obese.
Persons who are overweight or obese are at increased risk of chronic health conditions, such as type 2 diabetes, some types of cancer, high blood pressure and heart disease, as well as joint and muscle pain.
When might treatment be considered?
Weight loss medication is designed to be taken alongside a reduced calorie diet programme and exercise. In many cases it is prescribed to those with a BMI of 30 or above; but it may be issued to those who have a BMI of 27 with a weight-related condition, such as type 2 diabetes, high cholesterol or blood pressure.
How does Mysimba work?
Mysimba tablets contain two active ingredients, called bupropion and naltrexone. The first of these, bupropion, works by raising the activity level of dopamine in the brain. This helps to limit the user’s appetite, and facilitates processes in the brain which deal with the expense of energy in the body. The other ingredient, naltrexone, also works in the brain and central nervous system, to reduce cravings for food.
A study of the US version of this drug, Contrave, found that on average people using it lost 5 percent of their total body weight after 13 months.
Where can I get Mysimba online?
Mysimba is available to buy online from our UK pharmacy. Every order made through our site is checked by a GMC-registered practitioner, who will only issue a prescription if your medication is suitable for you. Following approval, your order will then be dispensed by our UK-based pharmacy and shipped by tracked next-day delivery.
Follow the instructions given by your prescriber when taking this medicine. This will help to ensure the drug works as it should, and limit the risk of side effects.
- To be effective, Mysimba needs to be taken as part of a weight loss programme also including diet and exercise.
- Mysimba is not suitable for people with uncontrolled hypertension (high blood pressure). Before you start taking Mysimba, you will need to have your blood pressure checked to ensure it is safe for you.
- The Mysimba dose is gradually increased during the first four weeks.
- The starting dose is one tablet, taken once a day in the morning. Continue for one week.
- At the start of week 2, increase the dose to one tablet, twice daily (one in the morning, one in the evening).
- From the start of week 3, increase the dose to two tablets in the morning, and one in the evening.
- From the beginning of week 4, take two tablets in the morning and two in the evening.
- Continue taking this dose for the remainder of the course, as specified by your doctor.
- Please note that this medicine may cause sleep disruption if it is taken close to bedtime.
- Your doctor will review your treatment after 16 weeks, and at regular intervals thereafter, and assess whether you should continue taking it.
- Tablets should be swallowed whole with water, and ideally be taken at the same time as food.
- Do not exceed the dose specified by your prescriber.
- If you miss a dose, skip it and continue taking your medication as normal. Do not take a double dose to make up for a missed one.
The above is only a guide. Please refer to the instructions issued by your prescriber, and read the directions in the patient information leaflet in full before taking this medicine.
If you are unsure about any aspect of taking this drug or need further assistance, contact your doctor or pharmacist.
It is important to be aware of the potential side effects associated with your treatment, as some may require immediate medical attention.
Mysimba is a ‘black-triangle’ medication. In the UK, this status is issued by the MHRA to all new drugs when they are first released on the market, as well as those which are being used for a new purpose. It means that the medicine is still under close monitoring for its capacity to cause side effects.
If you notice any side effects not listed below, you can report them to the MHRA through the Yellow Card Scheme.
If you experience any signs of an allergic reaction (such as hives, or swelling in the face, lips or throat), any signs of a seizure, or any other side effects that become serious, seek medical help right away.
Very common (more than 1 in 10 people):
Nausea, vomiting, pain in the abdomen, constipation, headache, difficulty sleeping, anxiety, agitation, and joint and muscular pain.
Common side effects (less than 1 in 10 people):
Low white blood cell count, dizziness, vertigo, tremor, irritability, feeling depressed, mood disorders, fever, reduced appetite, diarrhoea, changes in the taste of food, dry mouth, toothache, not being able to concentrate, tiredness, drowsiness, lethargy, tinnitus, fast or irregular heartbeat (such as palpitations), hot flush, watery eyes, upper abdominal pain, delayed ejaculation, chest pain, changes in electrocardiogram activity, excessive sweating, hives, rash, itching, or hair loss.
Uncommon (less than 1 in 100 people):
Cold sores, athlete’s foot, swollen glands in the neck, armpit or groin, dehydration, anorexia, increased appetite, weight gain, abnormal dreams, agitation, hallucinations, confusion, paranoia, disorientation, loss of libido, loss of balance, amnesia, mental impairment, presyncope, motion sickness, ear discomfort, visual disturbances, blurred vision, eye irritation, photosensitivity, nasal congestion, runny nose, sneezing, sinus disorder, sore throat, increase in mucus, difficulty breathing, cough, fluctuations in or increased blood pressure, lower abdominal pain, flatulence, swollen lips, passing blood with stool, hernia, haemorrhoids, inflammation of the gallbladder, intervertebral disc protrusion, jaw and groin pain, sudden urge to urinate, frequent or painful urination, irregular menstrual bleeding, vaginal dryness, erectile dysfunction, feeling thirsty, cold extremities, increased creatinine levels in the blood, increased liver enzymes, hepatitis, decreased haematocrit, acne, or oily skin.
Rare (less than 1 in 1,000 people):
Unusual bleeding or bruising under the skin, blood sugar fluctuation, feeling irritable or hostile, suicidal thoughts, suicide attempts, feeling of seeing yourself from outside your body or sense of unreality of surroundings, muscle stiffness, uncontrolled movements, loss of coordination, tingling or numbness in the hands or feet, widening of blood vessels, low blood pressure when standing, jaundice, erythema multiforme, Stevens Johnson Syndrome, deterioration of psoriasis, muscle twitching, or urinary retention.
Very rare (less than 1 in 10,000 people):
Angioedema, severe allergic reaction, delusions, aggression, muscle and kidney problems.
Please refer to the leaflet provided for more information on side effects.
Taking it with other medicines
Tell your prescriber about any other medicines you are taking during consultation. These should include any prescription, over the counter or remedial treatments.
Do not take Mysimba if you are taking: monoamine oxidase inhibitors, such as phenelzine, selegiline, or rasagiline; or opiates and opiate-containing medicines such as mixtures containing dextromethorphan or codeine methadone, morphine, or peregoric (or similar medicines for diarrhoea). Naltrexone has the capacity to interact with opiates even after you have finished taking it, so you should always tell your doctor if you are taking or have recently taken Mysimba.
Your doctor also needs to know if you are taking the following: medicines that may, when used on their own or together with naltrexone/bupropion, increase the risk of fits such as antidepressants or treatments for other mental health problems; steroids; antimalarials; quinolones; tramadol; theophylline; antihistamines; medicines to lower blood sugar levels such as insulin, sulphonylureas such as glyburide or glibenclamide, and meglitinides such as nateglinide or repaglinide); sedatives such as diazepam; desipramine, venlafaxine, imipramine, paroxetine, citalopram, risperidone, haloperidol, or thioridazine; high blood pressure treatments such as betablockers or centrally
acting antihypertensives; treatments for irregular heart rhythm such as propafenone; flecainide; cancer treatments such as cyclophospamide, ifosphamide, tamoxifen; medications for Parkinson’s disease such as levodopa, amantadine or orphenadrine; ticlopidine or clopidogrel; antiviral treatments for HIV such as efavirenz and ritonavir; or medicines for epilepsy such as valproate, carbamazepine, phenytoin or phenobarbital.
Conditions to look out for
Tell your doctor about any conditions you have during consultation.
You should not take Mysimba if you: are allergic to any of the ingredients in it; have uncontrolled, abnormally high blood pressure; have a condition that causes fits or a history of fits; have a brain tumour; are usually a heavy drinker and have just stopped drinking alcohol, or intend to stop while taking Mysimba; have recently stopped taking sedatives or medicines for anxiety (such as benzodiazepine), or intend to stop while taking Mysimba; have bipolar disorder; are using any other medicines which contain bupropion or naltrexone; have an eating disorder or have had one in the past; are currently dependent on chronic opioids or opiate agonists, or are going through acute withdrawal; are taking monoamine oxidase inhibitors (MAOIs) or have taken them in the last 14 days; have severe liver disease; have severe, or end-stage kidney disease.
Tell your doctor before taking Mysimba if you: have a history of attempting suicide; have a history of any other mental health problems; have had a serious head injury or head trauma; regularly drink alcohol; regularly use sedatives; are currently dependent on or addicted to cocaine or other stimulating products; have diabetes; have high blood pressure; have uncontrolled coronary artery disease; have or have had a condition affecting the circulation of blood in the brain; have any liver problems; have any kidney problems.
If you are over 65
Caution is advised when taking Mysimba if you are over 65.
It is not recommended for use in over 75s.
Pregnancy and breastfeeding
This medication is not suitable for use during pregnancy or breastfeeding, or for use by those who are trying to conceive.
Driving and using machinery
If you experience dizziness while taking Mysimba, do not drive or operate machines.
Drinking alcohol to excess while taking Mysimba increases the risk of seizures and mental health problems. Mysimba can also reduce alcohol tolerance. Your doctor may advise you to stop drinking alcohol completely or keep consumption to a strict minimum while taking this treatment.
If you do drink heavily now, you should not suddenly stop, as this may increase the likelihood of you having a seizure.
This medicine contains lactose. Speak to your doctor before use if you have an intolerance to lactose or any other sugars.
Can I still drink alcohol?
Drinking a lot of alcohol while taking Mysimba increases the risk of seizures. When taking Mysimba, your doctor will likely advise you to keep your alcohol intake to a minimum, or not drink at all. If you tend to drink a lot of alcohol now, talk to your doctor before taking this treatment.
Will I still be able to drive?
If you notice any side effects which may inhibit your capacity to drive, such as dizziness or loss of coordination, do not drive and speak to your doctor.
Can I use this medication while pregnant?
No. It is not suitable for those who are pregnant, breastfeeding or trying for a baby.
How do I store it?
Store below 30°C in a safe place out of the reach of children.
Am I allergic to anything in the medicine?
This tablet contains: bupropion hydrochloride, naltrexone hydrochloride, microcrystalline cellulose, hydroxypropyl cellulose, lactose anhydrous, lactose monohydrate, cysteine hydrochloride, crospovidone, magnesium stearate, hypromellose, edetate disodium, colloidal silicon dioxide, polyvinyl alcohol, titanium dioxide (E171), macrogol 3350, talc and indigo carmine aluminium lake (E132).
Do not use it if you are allergic to any of the above ingredients.
Is it available over the counter?
No. Mysimba is only available on prescription. If you have already been taking this medication, and are looking to renew your prescription, you can do so using our secure online consultation facility.
Is it right for me?
The best person to speak to before embarking on a weight loss treatment programme is your GP. They will be able to explain the risks and benefits of weight loss medicine, how it works and whether or not you need it, and to help you set out a diet and exercise plan.
What happens when you order Mysimba online
Renewing your prescription for Mysimba is easy with our online consultation process. Take our questionnaire, and your case will be reviewed by our doctor. Approved orders are shipped by next-day tracked courier from our UK pharmacy.
Search for your medicineFind the treatment you need.
Fill in a simple questionnaireA GMC-registered doctor or a pharmacy prescriber will review your answers.
24h delivery to your doorNext-day delivery. Every order is sent by tracked courier.
Repeat ordering is easyWe keep your details secure so you can reorder with ease.