The safety of weight loss pills can vary based on whether they are prescription medications or over-the-counter supplements. Prescription weight loss pills have undergone rigorous testing and are generally considered safe when used under medical supervision. However, they can still have side effects, such as nausea, bowel changes, and increased blood pressure. Over-the-counter weight loss supplements are not as strictly regulated and may pose risks due to unverified ingredients or incorrect dosages. It’s essential to consult with a healthcare professional before starting any weight loss pill, even if they are available without prescription.

Weight loss pills work through different mechanisms, depending on their active ingredients. Here are a few common ways they work:

• Appetite suppressants. These pills help reduce hunger and cravings, making it easier to eat less. They often work by affecting brain chemicals that regulate appetite.
• Fat absorption inhibitors. These medications prevent the absorption of fat from the food you eat, reducing overall calorie intake. Orlistat (Xenical) is a well-known example that works this way.
• Metabolism boosters. Some pills contain ingredients that can help increase your metabolism, allowing your body to burn more calories throughout the day.

There are many non-prescription products marketed for weight loss in the UK. These may include:

• Caffeine-based fat burners
• Green tea extract
• Fibre supplements like glucomannan

Important Note: the evidence behind most over-the-counter slimming pills is limited, and many are unregulated.

Always check with a pharmacist or GP before using any weight loss supplement, especially if you have underlying conditions or are taking other medication.

Yes, a GP can prescribe weight loss pills (aka “slimming tablets”) if you meet the eligibility criteria.

For example, Orlistat (Xenical) is available for those with a BMI of 30 or higher, or a BMI of 28 or higher with additional weight-related health conditions like diabetes or hypertension. The NHS may also require a patient to be assessed by a specialist, which often has long wait times.

If you do not qualify for an NHS prescription or prefer a different medication, you can seek an assessment with a private prescription service. This would involve an additional cost, which can be higher but may provide access to a broader range of medications.