5 Prescription Weight Loss Drugs and the Results to Expect (2018)*

Prescription Weight Loss Pills

Frustrated with diet and exercise? Prescription weight loss drugs can offer some guaranteed weight loss results, but only when used correctly under the consultation and supervision of a qualified physician.  Saxenda, Apidex and Suprenza, Qysmia, Contrave, and Belviq are the five approved prescription drugs for weight loss.

There are many valid reasons for not being able to lose weight through lifestyle changes and there is no harm in seeking professional medical help for weight loss. Doing it safely with the correct professionals can help you achieve some amazing weight loss results.

Most of the time prescription weight loss drugs are exactly what you need to get you onto the path to weight loss success.

These are the results you can expect with the prescription weight loss drugs Apidex and Suprenza, Qysmia, Contrave, Belviq and Saxenda.


The information provided in this article is for informational purposes only. The information in this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Every individual should always seek the advice of a physician or other qualified health providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it based on any information in this article.  

* the results displayed below are average results from clinical trials and individual results may vary.

Prescription Weight Loss Drug Safety

  • Always consult a registered physician before taking any medication.
  • Get a legal prescription and get your medication from an established pharmacy.
  • Never buy prescription pills online, from websites, or your local personal trainer.
  • Never try out medication prescribed for someone else.

Approved Prescription Weight Loss Drugs (2018)

For a drug to considered effective for weight loss, the drug has to be able to cause a minimum loss of 5% of your weight. Bear in mind that people that participate in these drug trials have to be obese with a BMI over 30 to be included in the trial.

Most studies also include a restricted calorie plan and some include an activity plan to be followed while taking the drug. None of these prescription weight loss drugs will cause weight loss if you continue to eat excessively however they will help you stop eating excessively.

The five drugs included in this article all meet the criteria for approval as a prescription weight loss drug. They all have different modes of action to help you lose weight and only a professional can help you decide which drug is best for you.

Prescription weight loss drugs

* these are average results from clinical trials and individual results may vary.

Phentermine (Apidex-P, Suprenza) Weight Loss Results

This is the oldest prescription weight loss drug on the market. It has been around since the 1960’s and is approved for short term use of up to three months however, it is used for much longer periods in practice.

It works by activating the sympathetic nervous system causing a release of norepinephrine which causes an increase in your resting metabolic rate. This means you will burn more energy even when you are sitting down leading to a calorie deficiency and weight loss.

Norepinephrine also plays a major role in appetite suppression. Phentermine can literally stop your appetite all together and this plays a major part in helping you stick to a diet.

Results to Expect with Phentermine (Apidex-P. Suprenza)

Most of the studies done on phentermine are from the 1960’s and 70’s, however there was a study done in 2010 that showed significant weight loss results for phentermine.

Participants took the standard daily dosage of 30mg and on average, lost 9.2% of their weight. In actual terms this worked out to about 17.8 pounds.

More than 53% of the patients lost more than 10% of their weight with many patients losing up to 26.4 pounds.

The average number of people that lost more than 10% of their weight is quite high and this means that the drug works well for most people.

Side Effects with Phentermine (Apidex-P. Suprenza)

The most common side effects include insomnia, dry mouth, dizziness, and irritability. The insomnia is cured by taking your dosage as early as possible. Dizziness and irritability are also caused by the lack of eating as you often forget to eat when on Phentermine. Set reminders to eat and make sure you eat even if you are not hungry.

Phentermine/Topiramate (Qysmia) Weight Loss Results

Topiramate is used mostly to treat migraines, and some cases of epilepsy, however it was discovered that patients taking it experienced a decrease in appetite and subsequent decrease in calorie intake.

This lead to topiramate being used in conjunction with phentermine for weight loss. The combination of the two drugs also allows you to use smaller dosages leading to less side effects.

Topiramate works particularly well to inhibit compulsive food cravings and addictive food behaviours such as binge eating. This is combination is the only product able to increase energy expenditure and suppress appetite.

Results to Expect with Phentermine/Topiramate (Qysmia)

Qysmia and its dual effect have been proven to get some excellent weight loss results. The strongest dosage contains 15mg of phentermine and 92mg of topiramate.

In a 2011 study, the participants who completed one year of taking a daily dose of Qysmia experienced an average weight loss of 12.4%. This translated to an actual average weight loss of 28.4 pounds.

More than 48% of these participants lost more than 10% of their weight.

Side Effects with Phentermine/Topiramate (Qysmia)

You can expect similar side effects to phentermine on its own, however the phentermine side effects are lower due to the lower dose.

The topiramate dose is also low causing minimal side effects however there are major warnings with topiramate. It should not be taken by patients with previous mental health issues and should never be taken while pregnant or even if you are trying to fall pregnant. 

Locaserin (Belviq) Weight Loss Results

This prescription weight loss drug was approved in 2012, it also works by suppressing your appetite in your hypothalamus.The hypothalamus is the main area in the brain that regulates our appetite.

Locaserin suppresses appetite by blocking serotonin receptors in the hypothalamus.It also increases the feeling of fullness. It does this by stimulating neurons in the hypothalamus that are responsible for creating the feeling of fullness. This action keeps you feeling full for longer and thereby reduces calorie intake resulting in weight loss.

Results to Expect with Locaserin (Belviq)

Locaserin weight loss results are not as impressive as the others but the drug does have a better side effect profile, and is suitable for people who are not obese but just need a little help getting in shape.

A study showed that after 52 weeks of taking 10mg of Locaserin twice daily, patients experienced an average weight loss of 5.8%. The actual average weight loss was about 12.8 pounds.

Side Effects with Locaserin (Belviq)

Locaserin side effects include dizziness, fatigue, nausea, and dry mouth. These can be mitigated by eating correctly and not starving yourself. Diabetic patients on other diabetic medication stand an increased chance of hypoglycaemia when taking Locaserin.

Naltrexone/Bupropion (Contrave) Weight Loss Results

This combination prescription weight loss drug was recently approved in 2014. Bupropion is an old drug that was used to treat depression. It became popular after proving to be very effective in helping smokers quit.

Naltrexone is also an old drug that is very effective in helping heroin addicts and alcoholics quit their addictions. Addictions affect the same areas of the brain that control appetite and weight.

The combination of the two drugs work synergistically to decrease appetite, cravings, and food addictions all resulting in decreased calorie intake for extended periods of time.

Results to Expect with Naltrexone/Bupropion (Contrave)

A study in 2011 researched the effects of an intensive behavioural modification program (BMOD) on weight loss compared to the combination of a behavioural program plus Naltrexone/Bupropion and the results were surprising.

The BMOD program which entailed programs on dieting and exercising caused an average weight loss of 5.1%. However, when they added in Naltrexone/Bupropion 32/360mg daily, the average weight loss increased to 11.5% after 56 weeks. That’s an actual average weight loss of 25.4 pounds.

The shocking part of this study was that more than 55% of the participants who completed the study lost greater than 10% of their weight and almost 40% of them lost more than 15% of their weight”.

Side Effects with Naltrexone/Bupropion (Contrave)

This combination also causes the common side effects of nausea, constipation, headaches, and dizziness. It is also contraindicated in pregnancy and in patients with a history mental health issues. The drug interacts with some antidepressants and can lessen the efficacy of opioid pain killers.

Liraglutide (Saxenda) Weight Loss Results

This injectable prescription weight loss drug was originally prescribed for the treatment of diabetes. It was later noticed that most patients on this drug lost a lot of weight, so the drug was trialled and approved as a weight loss drug.

Liraglutide (Saxenda) is a hormone that is found in our bodies. The liraglutide (Saxenda) produced by our bodies is active for a very short period, usually only one to two minutes. The drug liraglutide (Saxenda) has been modified to be active for up to 13 hours.

The main role of liraglutide (Saxenda) is to block areas of your brain that prompt you to eat. In doing this, it can significantly decrease your appetite and total calorie intake. Liraglutide (Saxenda) also has several other metabolic effects that aide with weight loss. Another big advantage is that Liraglutide (Saxenda) is different from other drugs in that you never plateau and continue to lose weight with extended use.

Results to Expect with Liraglutide (Saxenda)

A very recent study published in 2015, showed that after 56 weeks of 3mg daily doses of Liraglutide (Saxenda), participants of the study lost an average weight of 8% and an actual average weight of 18.5 pounds.

Liraglutide (Saxenda) works well for average weight loss but worked extremely well for some participants who lost up to 34.6 pounds.

Liraglutide (Saxenda) is only available as an injectable drug and this is usually a major drawback but the results speak for itself.

Side Effects with Liraglutide (Saxenda)

The most common side effects with Liraglutide include nausea, constipation, and fatigue. The drug carries a serious risk of hypoglycemia especially in diabetic patients on other diabetic medication. Patients on insulin should not use Liraglutide.




When used safely, prescription weight loss drugs can deliver excellent results for so many people that struggle to lose weight through diet and exercise. It’s a great way to get started on weight loss while you implement lifestyle changes.

Consult your physician to find the weight loss prescription drug that is correct for you.

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  • The Aesthetic Pharmacist on

    Saxenda can be used for weight loss in people without diabetes. The active ingredient Liraglutide is prescribed and used in different doses for weight loss and diabetes.

  • Jack on

    Is Saxenda ONLY prescribed to people with diabetes?

  • trench34 on

    belviq doesnt deserve to be on this list

  • Kam on

    Duromine is a trade name for phentermine, the first drug in this article.

  • Jean on

    what about duromine?

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