Losing weight isn’t easy, especially when hunger cravings get in the way. If you’ve tried dieting but struggle with appetite control, you may be considering appetite suppressant tablets to help curb cravings and stay on track with your weight loss goals.
But what exactly are appetite suppressants? How do they work? And which one is right for you?
What are appetite suppressant pills?
Appetite suppressants are medications designed to help reduce hunger, making it easier to quieten food noise, eat less, and lose weight (1). These drugs target the body’s hunger signals, helping reduce food cravings and lower your caloric intake.
The most talked-about appetite suppressants are GLP-1 weight loss injections (2), but appetite suppressant tablets also exist, where instead of injecting a medicine, you take it orally as a pill. As these tablets help you lose weight, they are considered a type of weight loss tablet. However, unlike your traditional fat binders (also called lipase inhibitors and include Orlistat, Orlos, and Alli), which block fat absorption (3), appetite suppressants work by influencing the hunger signals in the brain, like GLP-1s (2).
While these medications can be helpful, especially for people who cannot or prefer not to use injections, they aren’t a magic fix. They work best alongside a balanced diet, regular exercise, and long-term, healthy lifestyle changes.
What appetite suppressant tablets are there?
In the UK, the most effective appetite suppressant tablet is Mysimba, which contains two drugs: naltrexone and bupropion (4). These two drugs work together to affect the brain’s reward system and hunger signals, reducing cravings and helping to control emotional eating.
Research shows that Mysimba can help you lose weight, but don’t expect immediate results. You’ll need to take the appetite suppressants for around four months first. However, if you keep it up, these pills can help with weight loss.
Studies found that those taking Mysimba for a year (along with a healthy diet and exercise) lost about six times more weight on average than diet and exercise alone and were about three times more likely to lose 10% or more of their body weight (5).
These appetite suppressant pills are only available on prescription, and you’re unlikely to get them from your NHS doctor due to cost. This means that many people look to get it privately through a service like Oxford Online Pharmacy.
If you don’t want to pay for a private prescription, some over-the-counter products are marketed as appetite suppressants, but these tend to be herbal supplements rather than licensed medicines. They may offer mild effects but are generally not as effective as prescription treatments like Mysimba.
Who can use appetite suppressants?
Appetite suppressant tablets like Mysimba may be prescribed to people with a BMI of 30 or higher (6). If you have a weight-related health condition (such as diabetes or high blood pressure), you may be able to get Mysimba tablets if your BMI is 27 or more (6).
However, they aren’t suitable for everyone. You may not be able to take Mysimba if you (4, 6):
- Are planning to become pregnant or are pregnant or breastfeeding.
- Have uncontrolled high blood pressure or certain heart conditions.
- Have a seizure disorder or have a previous history of seizures.
- Are taking medications that interact with appetite suppressants.
- Are allergic to bupropion, naltrexone, or any of the ingredients.
- Have been previously diagnosed with anorexia or bulimia.
- Have a history of bipolar disorder.
- Have end-stage kidney failure.
If you have a diagnosed eating disorder like binge eating disorder (BED), you won’t be able to get Mysimba through our remote service. However, that doesn’t mean the treatment is unsuitable for you, and studies have found it an effective BED treatment (7). It just means you’ll need to see a specialist in person to discuss a prescription, as they can provide a more in-depth assessment of your needs.
There have also been concerns over the cardiovascular safety of Mysimba. However, a large review that looked at results from five clinical trials found no increased risk (8).
What are the side effects of appetite suppressant tablets like Mysimba?
Like all medications, appetite suppressants such as Mysimba can cause side effects in some people.
The most common side effects include:
- Nausea
- Constipation
- Headache
- Dry mouth
- Trouble sleeping (insomnia)
These may affect more than 1 in every 10 people who use this medicine.
Less common, but more serious side effects can include increased blood pressure or heart rate. Your prescribing doctor will review your health and medical history to make sure Mysimba is a safe option for you.
A full list of possible side effects is available in the Mysimba patient information leaflet.
Hunger suppressant vs weight loss pills: What’s the difference?
If you’re looking into oral weight loss treatments, you’ve probably come across appetite suppressant tablets like Mysimba and fat-blocking medications like Orlistat. While both can support weight loss, they work in different ways and are best suited to different needs.
- Mysimba targets the brain’s hunger and reward system, helping to reduce cravings and emotional eating. This means it might be a good option if you struggle with constant food thoughts, overeating, or snacking even when you’re not hungry. It’s particularly effective for helping manage appetite and breaking long-standing, unhealthy eating habits.
- Orlistat is a fat-blocking medication (3). Instead of affecting hunger signals, it works in the digestive system by preventing the body from absorbing some of the fat you eat. If you consume a high-fat meal, Orlistat will stop about one-third of the fat from being absorbed, which can help lower overall calorie intake and aid weight loss (9).
Which are the best weight loss tablets for me?
Not sure whether to choose appetite suppressant tablets or fat-blocking weight loss pills? Here are some things to consider:
- What are your main barriers to weight loss? If you’re struggling with cravings, food noise, or emotional eating, hunger suppressant tablets like Mysimba may be the better option. But if you tend to eat high-fat meals and want to reduce absorption, Orlistat might be more suitable.
- Will you qualify for a prescription? Mysimba is only available on prescription, whereas you can buy both prescription-strength Orlistat (brand name Xenical) and a lower strength, over-the-counter (OTC) version, sold under the brand names Alli and Orlos.
- What is your budget? Mysimba is more expensive than Orlistat, setting you back over £100 for a month’s supply. In comparison, one month of Orlistat 120mg costs around £35, and OTC strengths are a similar price point. Unlike Mysimba, you can also get Orlistat on the NHS.
Where can I buy Mysimba safely?
If you’re considering appetite suppressant tablets, Mysimba is one of the best options. While it’s not typically available on the NHS due to cost, it’s still an effective treatment for weight loss when prescribed by licensed doctors and pharmacies.
At Oxford Online Pharmacy, we offer a discreet and convenient way to request prescription weight loss treatments through the Oxford Online doctor service. The medical team will assess your eligibility and, if appropriate, prescribe Mysimba to support your weight loss journey, quieten food noise, and help you form healthier eating habits.
Begin your online consultation today to get started.
References
- Silverstone T. Appetite Suppressants. Drugs. 1992 Jun;43(6):820–36.
- Moiz A, Filion KB, Tsoukas MA, Yu OHY, Peters TM, Eisenberg MJ. Mechanisms of GLP-1 receptor agonist-induced weight loss: A review of central and peripheral pathways in appetite and energy regulation. The American Journal of Medicine [Internet]. 2025 Jan 31;
- Liu TT, Liu XT, Chen QX, Shi Y. Lipase Inhibitors for Obesity: A Review. Biomedicine & Pharmacotherapy [Internet]. 2020 Aug 1;128(110314):110314.
- Package leaflet: MySimba 8mg/90mg prolonged-release tablets [Internet]. [cited 2025 Mar 12].
- Thomas B, Lindblad AJ, Luu T, Paige A. Naltrexone-bupropion for weight loss. Canadian Family Physician [Internet]. 2023 Sep 1 [cited 2024 Aug 15];69(9):627–7.
- BNF. Naltrexone with Bupropion. [Internet]. NICE.
- Grilo CM, Lydecker JA, Morgan PT, Gueorguieva R. Naltrexone + Bupropion Combination for the Treatment of Binge-eating Disorder with Obesity: A Randomized, Controlled Pilot Study. Clinical Therapeutics [Internet]. 2021 Jan 1;43(1):112-122.e1.
- Sposito AC, Bonilha I, Luchiari B, Benchimol A, Hohl A, Moura F, et al. Cardiovascular safety of naltrexone and bupropion therapy: Systematic review and meta‐analyses. Obesity Reviews. 2021 Apr 12;22(6).
- NHS. Treatment - Obesity [Internet]. NHS. NHS; 2023.