You clicked this because you want straight answers: what Contrave actually does, who it helps, how to take it, and how to get it in the UK. Here’s the reality check up front-naltrexone/bupropion (sold as Contrave in the US and Mysimba in the UK) won’t melt weight on its own. It can curb appetite and cravings, but the real wins come when it’s paired with a simple, sustainable routine: fewer ultra-processed snacks, consistent movement, and sleep that doesn’t wreck your appetite hormones.

• Contrave/Mysimba is a prescription-only combo (naltrexone + bupropion) that helps with appetite and craving control-expect ~5-10% body weight loss over 6-12 months if you pair it with lifestyle changes.
• In the UK it’s called Mysimba. It’s usually offered for BMI ≥30, or ≥27 with conditions like type 2 diabetes or hypertension.
• Titrate the dose over 4 weeks; take with a low-fat meal. Stop at 16 weeks if you’ve not lost at least 5% of your starting weight.
• Not for anyone with seizure history, eating disorders, uncontrolled blood pressure, current opioid use, or pregnancy. Interacts with many antidepressants and pain meds-check every script.
• NHS access varies; private prescriptions typically cost ~£100-£170 per 4 weeks. Consider alternatives like Wegovy (semaglutide) or orlistat based on health, budget, and availability.

What It Is, How It Works, and What Results Look Like

Contrave is a brand name for a fixed-dose combination: naltrexone and bupropion. In the UK and EU it’s marketed as Mysimba. Both medicines are old, familiar drugs. Bupropion is an antidepressant and smoking-cessation aid; naltrexone blocks opioid receptors. Together they act on the brain’s appetite and reward centres. In plain English: you feel less preoccupied with food, you get fewer "I need a biscuit right now" urges, and you hit fullness sooner.

Who it’s for: adults with BMI ≥30, or ≥27 if you also have weight-related conditions (like type 2 diabetes, dyslipidaemia, sleep apnoea, or high blood pressure). That’s the same ballpark as other weight-loss meds.

What to expect: in pivotal studies (the COR trials), people on naltrexone/bupropion plus lifestyle support lost notably more weight than those on lifestyle changes alone. The typical total weight loss lands around 8-11% at 1 year when the plan-food, movement, sleep-is consistent. About half of users hit at least 5% weight loss. These results come from large, peer-reviewed trials such as COR-I and COR-BMOD (Apovian et al., Obesity; Wadden et al., Obesity) and the U.S. FDA Prescribing Information and EU SmPC for Mysimba.

Realistic mindset: this is an assist, not a replacement for everyday habits. If your weeks are chaotic and sleep is a mess (hello, 01:00 fridge raids), the medication has to work much harder. On the flip side, even small habits compound: a 200-300 calorie daily deficit, 7-8k steps, 7 hours’ sleep-boring, but it works. I live in Birmingham and see this play out constantly: steady, not flashy, is how people keep the weight off.

If you’ve tried calorie counting and hit a wall because cravings steamroll your plan by 5pm, this medicine specifically targets that gap. That’s its niche.

Safe Use: Dosing, Side Effects, and Who Should Avoid It

Dose titration keeps side effects manageable. Here’s the standard schedule for Mysimba (UK) or Contrave (US):

Each tablet contains 8 mg naltrexone sustained-release and 90 mg bupropion sustained-release. Take whole-don’t cut or crush. Take with a low-fat meal; high-fat meals raise drug levels and can increase seizure risk. If you miss a dose, skip it-don’t double up.

Common side effects: nausea, constipation, headache, dizziness, dry mouth, insomnia, anxiety, and a bump in blood pressure or heart rate. Nausea tends to be front-loaded in weeks 1-3, then settles.

• Easy wins: smaller, low-fat meals; ginger tea; take the evening dose earlier to protect sleep; keep caffeine modest.
• Hydration and fibre help constipation-think oats, chia, berries, and a big glass of water with breakfast.

Serious risks and red flags (stop and speak to a clinician): seizures; severe allergic reaction; sustained blood pressure >140/90 if that’s new; suicidal thoughts or a marked mood shift; visual changes; severe abdominal pain; signs of liver problems (itching, dark urine, yellowing). The U.S. label carries a boxed warning about suicidality with antidepressants (bupropion). Safety information is set out in the FDA Prescribing Information and the EU/UK SmPC for Mysimba.

Who should not take it:

• Current or recent (within 14 days) use of MAOIs.
• Seizure disorder or a history of seizures; brain tumour; abrupt alcohol/sedative withdrawal risk.
• Uncontrolled hypertension.
• Eating disorders (bulimia or anorexia).
• Chronic opioid use, dependence, or acute opioid withdrawal (naltrexone blocks opioids; you’ll precipitate withdrawal and blunt pain relief).
• Pregnant, planning pregnancy, or breastfeeding.

Interactions you must check:

• Opioid pain meds (codeine, tramadol, morphine, oxycodone): naltrexone blocks them. You need a clear plan if you ever need surgery or acute pain relief.
• Antidepressants and antipsychotics: bupropion inhibits CYP2D6, which can raise levels of SSRIs (like fluoxetine), tricyclics, and some antipsychotics; dose adjustments and monitoring may be needed.
• Drugs lowering seizure threshold: tramadol, theophylline, systemic steroids at high doses-use with caution.
• Alcohol binges: increase seizure risk; keep drinking moderate or skip entirely.

Monitoring that actually helps:

• Baseline: blood pressure, pulse, weight, waist, meds review. If you have type 2 diabetes, check HbA1c and review hypoglycaemia risk as you lose weight.
• Early weeks: blood pressure and pulse weekly, symptoms diary, sleep quality.
• By week 16: aim for at least 5% weight loss. If not, it’s kinder to stop than to keep paying for no benefit.

Pregnancy and contraception: don’t use during pregnancy or breastfeeding. Use reliable contraception; reassess if you’re planning pregnancy. There’s no proven benefit vs. lifestyle during pregnancy, and the risk-benefit doesn’t stack up.

Driving and machinery: if you feel dizzy or your sleep is off, hold off driving until you feel steady. This is usually a short-term titration issue.

Simple decision helper:

• If your main struggle is cravings and evening snacking, and you’re not on opioids or high-risk interacting meds, this medicine is a good fit to discuss.
• If nausea terrifies you, or you have a seizure history, look at alternatives like orlistat or GLP-1s (pending availability and suitability).
• If your BMI is just above 27 with blood pressure or cholesterol issues, this may be considered if lifestyle attempts alone haven’t worked.

UK Access, Costs, and How It Stacks Up Against Other Options

Brand names matter here: in Britain it’s Mysimba. When you hear news from the U.S. about Contrave, you’re basically hearing about the same active ingredients. Supply in the UK has been patchy at times, so pharmacies may ask for a day or two to source it.

NHS vs private: NHS access varies by region and service capacity. Some weight-management pathways include medications after a structured lifestyle programme, but prioritisation often goes to GLP-1 agonists (like semaglutide) in people with higher risks. If you don’t meet local NHS criteria, private prescribing through regulated clinics is common.

Typical UK private costs (2025): around £100-£170 for a 4-week supply (112 tablets), plus an initial consult fee. Prices vary by clinic and follow-up model.

How long do people stay on it? Many use 6-12 months, then reassess. Some continue longer if weight is still moving in the right direction and side effects are minimal. If plateaus persist for months, it’s time to rethink the plan or switch.

Which is “best”? It’s personal. GLP-1s like semaglutide usually deliver the biggest average losses, but injections and supply issues aren’t for everyone. Mysimba shines when cravings are the sticking point and you want tablets, not needles. Orlistat is cheapest and works if you genuinely reduce fat intake.

What to ask your prescriber (bring this checklist):

• Do any of my current meds clash with bupropion (CYP2D6) or naltrexone (opioid blockade)?
• What’s our plan if I need pain relief or surgery while on this?
• How will we measure success by week 16, and what’s the stop/switch plan?
• What blood pressure monitoring should I do at home?
• What’s my backup option if nausea or insomnia won’t settle by week 3?

Budget and practicality tips:

• If your pharmacy is out of stock, ask them to check wholesaler alternatives or call ahead to a second pharmacy before you travel.
• Don’t hoard multiple months until you’ve proven you tolerate the full dose. Start with one month; scale after week 4.
• Use a simple food structure (protein + produce + wholegrain) and cap high-fat meals-this drug is fussy with fat for both comfort and safety.

Two quick real-world scenarios:

• Busy parent, BMI 33, constant evening raiding: Mysimba can blunt those 8-10pm cravings. Plan a 200-calorie controlled snack, early evening dose, lights-out by 23:00. Expect 5% by four months if the routine holds.
• On fluoxetine for anxiety: still possible, but you need a meds review because bupropion can raise SSRI levels via CYP2D6 inhibition. Start cautiously, monitor sleep and mood weekly, and loop in your GP or psychiatrist.

Authoritative sources for all safety and dosing statements here include: the FDA Prescribing Information (latest revision 2024), the European and UK Summary of Product Characteristics for Mysimba, and the COR clinical trials published in peer‑reviewed journals (Obesity; Lancet Diabetes & Endocrinology for class comparisons). I don’t dump links here, but these are easy to find by title.

Mini‑FAQ

Is Contrave available in the UK?

Yes, but under the name Mysimba. Your prescription will say Mysimba. Stock can vary by pharmacy.

How long before I feel anything?

Most people feel reduced snacking urges in weeks 2-3 as the dose climbs. Weight shifts usually start in the first month and compound if the routine sticks.

Can I drink alcohol?

Light drinking is usually fine, but avoid binges-they increase seizure risk. If you’ve had blackouts or withdrawals before, discuss frankly with your clinician before starting.

What if I take codeine or tramadol?

Not compatible. Naltrexone blocks opioids. If you need opioids for pain or a planned procedure, you need a different plan. This is non‑negotiable.

Can I combine this with GLP‑1 injections?

Sometimes, under specialist care, but it’s not routine in primary care. Start one medicine, judge response, then consider combinations if you’re in a specialist clinic.

Will I regain weight if I stop?

You might regain some if habits revert. The best hedge is to build one or two low‑effort anchors you’ll keep-protein-forward breakfast, fixed step target, phones out of the bedroom. These keep benefits after the script ends.

Is this okay with high blood pressure?

Only if it’s controlled and monitored. The medicine can raise blood pressure and heart rate a bit. If your readings creep up, pause and review.

What about antidepressants?

Possible but nuanced. Bupropion interacts with several antidepressants. Your prescriber should review doses and side effects carefully and may start slower.

Next Steps and Troubleshooting

If you’re thinking “this might be me,” here’s a clean path:

1. List your meds (including over‑the‑counter and supplements) and past conditions (especially seizures, eating disorders, liver/kidney issues, blood pressure).
2. Book a weight‑management chat with your GP or a regulated private clinic. Say you’re interested in Mysimba (naltrexone/bupropion) because cravings are your main barrier.
3. Get baseline numbers: weight, waist, blood pressure, pulse. If you have diabetes, plan for glucose checks as weight drops.
4. Agree on a 16‑week goal: 5% loss, better sleep, fewer binges. Put it in writing.
5. Start titration, stick to low‑fat meals, and run a quick daily log (meals, steps, sleep, side effects).
6. Review at weeks 4, 8, and 16. If you don’t hit 5% by week 16, switch paths-no shame, just data.

Troubleshooting common snags:

• Nausea won’t settle by week 3: shift doses earlier, keep fat low, add ginger or peppermint, and ask about a short course of an anti‑nausea med. If it’s still grim, consider stopping.
• Insomnia or jittery: move the evening dose to late afternoon; keep caffeine before 13:00; dark, cool bedroom. If sleep is still poor two weeks in, review the plan.
• Blood pressure bump: verify with a calibrated cuff; cut caffeine; check pain meds (some raise BP); share readings. Safety first.
• Weight stall after a good start: audit portions (especially oils, nuts, latte calories), bump daily steps by 2k, and anchor sleep at 7 hours for two weeks. Tiny tweaks often restart progress.
• Travel and time zones: keep roughly 12 hours between doses. If that’s messy, prioritise sleep and miss the awkward dose-don’t double up.

Last word from experience: the people who do well on Mysimba don’t chase perfection. They build two or three routines they can keep on knackered days. My own hack is prepping a protein-forward lunch while Nimbus (my cat) yells for hers-habit stacked with habit. Boring wins usually beat heroic sprints.