With a number of slimming pills being availably only with a valid prescription issued by a certified medical professional, it comes as no surprise that not everyone is suitable for weight loss medications. These drugs can help optimise weight loss efforts when use in parallel to dietary regimen and workout routine, but they can be prescribed only to those who:

  • Have BMI of 27 or more
  • Are older than 18
  • Don’t have a history of certain medical conditions
  • Aren’t currently taking certain medications

What’s on this page?

Weight loss treatments in the UK

In the UK, there is only one compound that can be legally used in prescription treatments for weight loss, namely orlistat. As such, orlistat is an active ingredient of three slimming pills available in the UK – branded Xenical, generic Orlistat and over-the-counter Alli with decreased concentration of the active ingredient.

All of the mentioned medications work by preventing the fat from being absorbed in the gut, cutting the total fat intake by as much as one third and a quarter in case of Alli. The remaining fat which has not been consumed by the body will be passed through the system as faeces.

Who can use orlistat-based medications?

Of course, as orlistat-based weight loss tablets are prescription medications, not everyone can use them and there are specific criteria that must be met before the doctor can decide to prescribe any of the aforementioned medications. One of the most commonly used indicators used to determine if an individual is suitable for weight loss treatment is the body mass index, better known by its abbreviation BMI. BMI is a number that is calculated using a specific formula that relies on weight and height as its variables.

Usually, the patient will have to have a BMI of 30 or above, or 27 with accompanying obesity-related medical condition (hypertension, high cholesterol or diabetes for example) in order to obtain a prescription for any of the prescription weight loss medications.

In addition to this, drugs such as Xenical or Orlistat will be prescribed only to those patients who are dedicated to their goal of losing weight, since neither of these is a ‘magic pill’ that will simply melt away the excess pounds. On the contrary, in order to be effective, weight loss medications must be used in parallel with a healthier diet and exercise routine. The doctor will likely help you to make plans regarding making these lifestyle changes and implementing them properly.

The first three months of your weight loss treatment are often considered to be the most crucial. During this period, the doctor will closely monitor your progress and suggesting eventual changes if needed. In this period, the desired amount of weight loss is usually around 5% of your total weight. Depending on how close you manage to get to this goal, the doctor might decide to change or even completely halt your treatment.

Can I use weight loss medicines safely?

As has been said multiple times in this article, prescription slimming pills cannot be used by anyone safely, so you might not be suitable for treatments of this type.

  • If your BMI is below 25, you should not use weight loss medications
  • Slimming pills should not be used by pregnant women
  • Women who are currently breastfeeding should avoid orlistat-based medications since trace amounts of medicine can be passed into the milk
  • Anyone under 18 years of age should not use these medications
  • People affected by chronic malabsorption syndrome or cholestasis should not use weight loss medication
  • People struggling with kidney disease can use weight loss pills only under strict monitoring
  • Any kind of allergic reaction to Xenical or Orlistat indicates you should halt treatment immediately and avoid these medications in the future

Unwanted interactions with weight loss medicines

It has been proven that weight loss treatments can interact with other medications you might be taking at the same time, potentially compromising their effectiveness. Of course, during the consultations with your doctor, you should disclose all information regarding your medical profile and history, and this includes any and all treatments, medicines or supplements you might be taking at the same time, regardless of whether they are prescription-only or over-the-counter.

It is important to note that diarrhoea is a relatively common side effect or orlistat-based slimming pills, and a side effect that can even impede the efficacy of oral contraceptive pills. If you are using the pill as your preferable contraception method, but plan to start taking weight loss medications, you should consider switching to alternative contraception methods, ideally barrier contraceptives.