Personal training covers more ground than simply cultivating strength and building endurance. Many clients turn to us for weight-related health problems, and the two-pronged diet-exercise approach often proves highly successful. However, for the client who repeatedly and consistently tries diet and exercise without seeing any progress, a different approach might work better. Every trainer should be familiar with the currently available weight loss drugs on the market and be prepared to share this information with clients who ask.

Medical Intervention

Sometimes, the solution manifests itself in the form of a medically supervised program that includes a weight-loss drug. At this point, trainers must take a step back and allow the client to pursue this option outside of our expertise but along side our guidance. Typically, a physician will take into consideration the individual’s diet and exercise history as well as current health challenges before deciding if this course of action makes prudent sense.

Prior to embarking on such a program, patients should fully understand that weight-loss drugs do not “do the work for you”. A total comprehensive restructuring plan must also include a calorie-restricted diet, scheduled appropriate exercise, and behavior modification coursework.

The Weight Loss Drug Options

Since 2012, the U.S. Food and Drug Administration has approved the following four pharmaceuticals for purposes of weight loss:

  • Bupropion-naltrexone (Contrave)
  • Liraglutide (Saxenda)
  • Orlistat (Xenical)
  • Phentermine-topiramate (Qsymia)

Most of these work by decreasing appetite and/or increasing the sensation of satiety. Orlistat, however, works by interfering with the body’s fat absorption process.

Bupropion-naltrexone combines a drug used to combat alcohol and opioid dependence with an antidepressant. Like all antidepressants, this medication poses a suicide risk. Monitoring blood pressure levels for potential elevation must begin at the onset and continue throughout course of treatment. The most commonly reported side effects include nausea, headache, and constipation.

Liraglutide, often used to manage diabetes, does not come in an oral preparation. Delivered by injection, liraglutide often induces nausea. Severe vomiting can limit its use in some individuals.

Orlistat, also available without a prescription in a reduced strength, is offered over-the-counter under the trade name of Alli. Known for its gastrointestinal side effects, such as loose stools and frequent expulsion of gas, patients on this drug must strictly adhere to a low-fat meal plan while taking this medication.

Widely Used, Occasionally Abused

Phentermine-topiramate extended-release, which combines the weight-loss drug phentermine with an anticonvulsant, represents the pharmaceutical most widely prescribed, and will figure prominently in the following discussion. This drug also stands alone as the most effective weight loss pharmaceutical available to date. A daily dose of 37.5 mg phentermine alone, taken over the course of 12 weeks, can lead to an average weight loss of 15.8 pounds. Pharmacies nationwide fill over 2 million prescriptions for phentermine every year.

Phentermine belongs to a class of drugs known as sympathomimetic amines, which work by decreasing appetite, increasing the amount of energy used by the body, and releasing dopamine and norepinephrine into the brain. Similar to an amphetamine, phentermine stimulates the central nervous system, increasing heart rate and blood pressure while decreasing appetite.

Phentermine carries with it a risk of addiction, often exacerbated when an individual has a concurrent addiction to drugs or alcohol. As such, experts caution against taking phentermine in conjunction with other appetite-suppressant drugs or herbal supplements, including alcohol and cannabis.

Side Effects

Commonly reported side effects include a dry mouth, dizziness, sleep disturbances, nausea, elevated blood pressure, irritability and diarrhea/constipation. Rare but more serious complications can affect the pulmonary and cardiac systems. Primary pulmonary hypertension (PPH), a rare and potentially fatal lung disease, occurs when elevated blood pressure affects the arteries in the lungs and the right side of the heart.

Symptoms can include shortness of breath, heart palpitations, a bluish tint to the lips and skin, fatigue, and swelling in the ankles. Valvular heart disease occurs when damage to the heart valves causes leakage, interrupting blood flow throughout the body.

Due to its risk of inducing fetal damage, pregnant women should avoid taking topiramate. Similarly, because the drug can potentially pass into breast milk, postpartum women should find a temporary alternative to nursing while taking the phentermine-topiramate combination.


[sc name=”nutrition” ]


The Convincing Science

A research study conducted in Korea aimed to verify the effectiveness and safety of phentermine for the purpose of weight reduction. The randomized, double-blind, placebo-controlled study lasted three months. The 68 volunteers, relatively healthy yet obese adults whose body mass index equaled or exceeded 25 kg/m2 , received either 37.5 mg/day of phentermine or a placebo. Both groups also received behavioral therapy for obesity.

After assessing for changes in body weight and waist circumference from the baseline, data revealed that the mean decrease of both parameters in phentermine-treated subjects significantly exceeded that of the placebo group. A large proportion of volunteers in the phentermine group accomplished a weight reduction of at least 5% from baseline, and at least a 10% modification in waist circumference.

Dry mouth and insomnia occurred more frequently in the group given phentermine, although to a mild extent, and none of the other commonly observed side effects posed problems. Scientists concluded that a short-term course of treatment induced significant reduction in weight and waist circumference with few if any problematic effects.

The Risk/Benefit Analysis

As with any issue of significance to one’s physical wellness, the debate over the pros and cons of weight loss drugs remains a hot topic. The daunting side effects of these pharmaceuticals, even under the watchful eye of a medical professional, pose enough of a concern for many to reconsider the idea of embarking on this path. In addition, the mental anguish brought on by society’s misguided views on obesity often push one into a decision that he or she later regrets.

If we find ourselves in the position to advise a client considering medical intervention, always keep in mind the legalities of our scope of practice. This is definitely an area where you can educate and offer information, as well as an empathetic ear, but leave the decision making to the client and his/her medical provider.

Weight loss drugs and severe caloric restriction seem like dire interventional methods, but also might prove the only logical choice for some who have struggled a lifetime with weight control. Our platform remains simple and consistent: remind the client that your dedication as a fitness professional will never waiver and you will continue to serve as a partner in his or her healthy journey as long as your guidance is needed.


[sc name=”masterfitness” ]



Cathleen Kronemer

Cathleen Kronemer

Cathleen Kronemer is an NFPT CEC writer and a member of the NFPT Certification Council Board. Cathleen is an AFAA-Certified Group Exercise Instructor, NSCA-Certified Personal Trainer, ACE-Certified Health Coach, former competitive bodybuilder and freelance writer. She is employed at the Jewish Community Center in St. Louis, MO. Cathleen has been involved in the fitness industry for over three decades. Feel free to contact her at She welcomes your feedback and your comments!