Taking a weight-loss medicine may be helpful when used in combination with diet, exercise and lifestyle changes, however, it is important to understand the risks and benefits.

First, it is essential to be realistic about your goal using a weight-loss medicine; you may not reach your “dream” weight, but you may be able to reduce your risk of diabetes or heart disease.

It is also significant to mention that if you do not lose at least five per cent of your initial body weight within 12 weeks of trying any of the below preparations, the medicine should be stopped.

In addition, it is critical to note that the track records on both efficacy and safety of the below drugs do not exceed two to four years.

Xenical (generic name, Orlistat)

Reduces the amount of fat your body absorbs from the foods you eat. A lower-dose version — brand name, Alli — is available over the counter.

After one year of treatment with Xenical, combined with lifestyle changes, the average weight loss is approximately 12 pounds. Cholesterol levels often improve and blood pressure sometimes falls. In people with diabetes, Orlistat may help control blood sugar levels. Side effects occur in ten to 15 per cent of people and may include stomach cramps, gas and diarrhoea. These problems are more likely when you take Xenical with a high-fat meal (ie, fat accounting for more than 30 per cent of meal calories). Side effects usually improve as you learn to avoid high-fat foods. Severe liver injury has rarely been reported in patients taking Orlistat, but it is not known if the latter caused the liver problems.

Belviq (generic name, Lorcaserin)

A medicine that reduces appetite and thereby reduces body weight. It appears to have similar efficacy as Xenical. Its adverse effects — headache, dizziness, nausea and upper respiratory infections — occur in seven to 18 per cent of patients. Belviq should not be used with anti-depression medications.

Qsymia (generic combo, Phentermine-topiramate)

Phentermine is a medicine that reduces food intake by causing early satiety (a feeling of fullness). Topiramate is used for the prevention of migraine headaches and epilepsy; it was found that patients taking topiramate for these indications lose weight, but the way this works is uncertain. Phentermine and topiramate are available in combination as a single capsule (Qsymia). In one-year trials, patients taking the medication lose approximately eight to ten per cent of their initial body weight (about 22 pounds). The most common adverse events are dry mouth, constipation, and a “pins and needles” sensation of the skin. There is also a risk of depression, anxiety and disturbance in attention. Qsymia should not be used in people with cardiovascular disease.

Saxenda (generic name, Liraglutide)

Liraglutide is approved by the US Food and Drug Administration for both weight loss and diabetes. When used for diabetes, it is called Victoza and has a lower dose. Patients without diabetes taking Saxenda for approximately six months lost 7.5 per cent of their initial body weight (16 pounds). Common adverse effects are nausea, vomiting, and diarrhoea, along with low blood sugar. While all the above medicines are taken as pills, Saxenda is injected under the skin in the abdomen, thigh or upper arm once daily.

Contrive (generic combo, Bupropion-naltrexone)

Bupropion is a medicine that is used to treat depression and to prevent weight gain in people who are trying to quit smoking. Naltrexone is a drug used to treat alcohol and drug dependence. In one-year trials studying a combination of bupropion-naltrexone (in one pill, Contrave), patients taking the medication lost approximately 5.5 per cent of their initial body weight (12 pounds). Common adverse effects include nausea, headache and constipation. Contrave should not be used in people with uncontrolled high blood pressure, a seizure disorder or an eating disorder.

Dietary supplements

These are widely used by people who are trying to lose weight. A few of the more common ones are discussed below. None of these are recommended because they have not been studied carefully and there is no proof that they are safe or effective.

1. Chitosan and wheat dextrin are ineffective for weight loss and their use is not recommended.

2. Ephedra, a compound related to ephedrine, is no longer available in the United States due to safety concerns.

3. There are not enough data about safety and efficacy to recommend chromium, ginseng, glucomannan, green tea, L-carnitine, psyllium, pyruvate supplements, St John’s wort and linoleic acid.

4. Two supplements from Brazil, Emagrece Sim (also known as the Brazilian diet pill) and Herbathin, have been in the spotlight over the past couple of years. They have been shown to contain prescription drugs at unregulated doses.

5. Bitter orange (Citrus aurantium) can increase your heart rate and blood pressure, and is not recommended.

6. Human chorionic gonadotrophin (hCG) is a hormonal preparation, usually given by injection, that has been advertised as a weight loss aid when combined with a very low-calorie diet. There have been several studies showing that hCG is no more effective than placebo; thus, it is not recommended.

• Joe Yammine is a cardiologist at Bermuda Hospitals Board. He trained at the State University of New York, Brown University and Brigham and Women’s Hospital. He holds five American Board certifications. He was in academic practice between 2007 and 2014, when he joined BHB. During his career in the US, he was awarded multiple teaching and patients’ care recognition awards. The information herein is not intended as medical advice nor as a substitute for professional medical opinion. Always seek the advice of your physician. You should never delay seeking medical advice, disregard medical advice or discontinue treatment because of any information in this article.