Are Appetite Suppressants Safe? (According to Science)

Prescription appetite suppressants are doctors' prescribed drugs or diet pills for weight loss.

Here's a shortlist of prescription medications:

• Lorcaserin (Belviq) - Belviq works to reduce appetite by acting on the 5-HT2C receptor for serotonin in the brain [3], which regulates feelings of fullness and hunger. It is recommended for people with a Body Mass Index (BMI) of 30 or 27 along with a weight-related condition.
• Phentermine (Adipex-P, Lomaira, and Suprenza) - Phentermine helps lessen food intake and improves energy released by your body. However, its downsides may include fast heart rate, hypertension, sleeplessness, and mental instability [4].
• Phentermine-Topiramate (Qsymia) - Qsymia is an extended-release capsule with two drugs, Phentermine which suppresses appetite, and Topiramate, which prevents seizures. It is advised for people with a BMI of over 27 or a weight-related condition to undergo a lifestyle change to lose weight.
• Naltrexone-Bupropion (Contrave) - Contrave is an extended-release capsule and contains two medicines, Naltrexone and Bupropion. Its combination works on the hypothalamus and the brain's reward system to promote satiety to manage excess weight gain [5]. It is recommended along with a low-calorie diet and workout plan to lose weight.
• Liraglutide (Saxenda) - Saxenda is an injectable drug that lessens hunger by producing an appetite hormone called Glucagon-Like Peptide (GLP-1), which slows stomach emptying. It is advised for people with a BMI of more than 27 along with a weight-related medical condition [6].  According to studies, you can continue using these drugs as long as they serve you well and offer no significant side effects [7].

Along with doctors prescribed medications, OTC natural supplements may help control appetite for weight reduction and management.

Here are some OTC drugs and how they work: 

• Fenugreek, Glucomannan, Acacia fiber, and Guar Gum lessen hunger by increasing fullness due to high soluble fiber content.
• Yerba Mate, Coffee, Green Tea Extract, and Guarana supplement weight loss by boosting metabolism due to high caffeine content.
• Garcinia Cambogia, Caralluma Fimbriata, and Griffonia simplicifolia are supplements known to control hunger pangs by increasing serotonin levels in the brain.
• Conjugated linoleic acid (CLA), Bitter Orange, Forskolin, and Saffron Extract are known to lower appetite by increasing fat breakdown.

Appetite suppressants, like any medications, may pose some harmful risks.

Here are the most commonly experienced side effects:

• Restlessness
• Dizziness
• Sleeplessness
• Dry mouth
• Constipation
• Loose Stools
• Increased Heart Rate

Side effects with appetite suppressants can differ depending upon the type of drug and how it works [8]. However, they can be mild to moderate but are still considered safe when taken under a doctor's supervision.

• People with Cardiovascular Problems. Research suggests that mild to moderate valvular heart disease showed one-third of the patients taking appetite suppressant drugs [9].
• People with Glaucoma. Appetite suppressants may tend to raise blood pressure [10] that can add more stress to your eyes. It can lead to blurred vision and permanent damage.
• People with Liver Disease. Some weight loss supplements may elevate liver enzymes in patients with existing liver damage, resulting in liver failure if not medically supervised [11].
• People with hyperthyroidism. Some OTC appetite suppressants might contain significant thyroid hormone levels that may affect the hormonal responses of patients with overactive thyroid problems [12].
• People who are taking antidepressant drugs. Some appetite suppressants tend to interfere and counter the effect of antidepressant drugs, which can cause serious side effects [13].