Weight Loss Medications vs

Weighing Your Options: Weight Loss Medications vs. Weight Loss Surgery

February 14, 2024

Weight Loss Medications vs. Weight Loss Surgery: Obesity is a chronic, relapsing disease that increases the risk of many additional health problems if left untreated. In 2000, 30.5% of American adults had obesity as compared to 41.9% today, and that number is expected to grow to 48.9% by 2030. Fortunately, a new class of weight loss drugs has catapulted obesity treatment to the center of attention in America. Unfortunately, weight stigma and misconceptions about weight-loss treatment have been widely circulated by celebrities on social media platforms, amplified by traditional news outlets, and have influenced members of the healthcare community and insurance providers.

Let’s cut through the nonsense and have a factual, judgement-free discussion about the burning question in our readers’ minds - “Which is better for me, weight loss medications or weight loss surgery?” Before you read any further, remember that this article should not be misconstrued as medical advice and is not a substitute for a consultation with an expert in obesity medicine or weight loss surgery.

What are the available weight loss drugs and surgeries? How do they work? What is the amount of weight loss I can expect for each option?

Four of the most prescribed medications for weight loss are phentermine (Lomaira, Adipex), phentermine + topiramate (Qsymia), bupropion + naltrexone (Contrave), and the glucagon-like peptide receptor (GLP-1) agonists: liraglutide (Victoza/Saxenda), semaglutide (Ozempic/Wegovy), tirzepatide (Mounjaro/Zepbound). The first three medications work by reducing appetite and cravings. The GLP-1 agonists work by reducing the forward motion of food in the intestinal tract and signal satiety to the brain. The most commonly performed weight loss surgeries are the gastric sleeve, roux-en-y gastric bypass, and the biliopancreatic diversion/duodenal switch. In the gastric sleeve procedure, the surgeon removes a part of the stomach, shrinking it from the size of a melon to the size of a banana. By reducing the size of the stomach, smaller meals produce satiety and the hunger signal to the brain is dampened.  In the roux-en-y gastric bypass, the surgeon “reroutes” the intestinal tract to delay food mixing with digestive juices. This results in fewer calories absorbed per meal, and may produce similar hormonal effects to the GLP-1 agonists. The biliopancreatic diversion/duodenal switch combines both a sleeve gastrectomy and roux-en-y gastric bypass and produces the most robust weight loss of all treatment options but carries more risk. There are other weight-loss medications and procedures available, but they are beyond the scope of this article. Please see the chart below to get a sense of the expected weight loss for each treatment option.

Weight Loss Medications vs
*Taken from Hendricks EJ, Greenway FL, Westman EC, Gupta AK. Blood pressure and heart rate effects, weight loss and maintenance during long-term phentermine pharmacotherapy for obesity. Obesity (Silver Spring) 2011;19:2351-60.
^Taken from clinical trial data found on company website
~% Weight loss attributed to lifestyle modification estimated based on Look AHEAD Research Group (2013). Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes. New England Journal of Medicine, 369(2), 145–154.
~% Weight loss for surgery estimated based off ASMBS Risk Calculator for white female with a BMI of 38 kg/m2 and no comorbidities. Estimates can be more specifically tailored to individuals by entering patient-specific information at https://riskcalculator.facs.org/bariatric/reportoutcomes.jsp

*Taken from Hendricks EJ, Greenway FL, Westman EC, Gupta AK. Blood pressure and heart rate effects, weight loss and maintenance during long-term phentermine pharmacotherapy for obesity. Obesity (Silver Spring) 2011;19:2351-60.

^Taken from clinical trial data found on company website

~%Weight loss attributed to lifestyle modification estimated based on Look AHEAD Research Group (2013). Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes. New England Journal of Medicine, 369(2), 145–154.

~%Weight loss for surgery estimated based off ASMBS Risk Calculator for white female with a BMI of 38 kg/m2 and no comorbidities. Estimates can be more specifically tailored to individuals by entering patient-specific information at https://riskcalculator.facs.org/bariatric/reportoutcomes.jsp

What are the adverse effects of weight loss medications vs. bariatric surgery? Will any of my medications be affected by weight loss medications vs. surgery?

Medications tend to have moderate adverse effects, but they tend to occur more frequently. For example, in patients taking the maximum dose of tirzepatide (Zepbound), nausea occurred in 28%, diarrhea occurred in 23%, vomiting occurred in 13%, and low blood pressure occurred in 2%. As with patients taking other weight-loss medications, these adverse effects often improved over time. New or worsening depression can occur when starting many weight loss medications, so close monitoring by an experienced medical professional is critical. Additionally, GLP-1 agonists can cause low blood sugar in patients taking medication for diabetes and may decrease absorption of other oral medications, including pills for birth control. See the table below for more information.

Drug Table

Phentermine tablets Adipex-P, Lomaira Reduces appetite

For short-term use (a few weeks) in
patients 17 years and older:

Adipex-P: 37.5 mg tablets  orally daily
Lomaira: up to 8 mg tablets orally three times a day

~3.6 kg (8 pounds) using up to 30 mg daily at 2-24 weeks1 ~97% of patients met weight loss goal (≥5%) at one year compared to 80% with placebo.3

Can increase heart rate and blood pressure Can cause insomnia Can cause withdrawal symptoms Discontinuation rate: unknown

Cost: Adipex-P: <$1/day Lomaira: ~$1.50/day  

Phentermine + topiramate extended release capsules Qsymia Reduces appetite

For patients 12 years and older:   3.75 mg/23 mg to 15 mg/92 mg capsules orally daily

~3.6 kg (8 pounds) using up to 30 mg daily at 2-24 weeks1 ~97% of patients met weight loss goal (≥5%) at one year compared to 80% with placebo.3

Can reduce sweating/increas body temperature especially with physical activity/hot weather Risk of birth defects Can worsen depression and/or suicidal thoughts/behaviors Risk of kidney stones with low fluid intake Can cause vision changes Can increase heart rate and blood pressure Can cause insomnia Can cause withdrawal symptoms Discontinuation rate: 1 out of 14 patients

Cost: Adipex-P: <$1/day Lomaira: ~$1.50/day  

Bupropion + naltrexone extended release capsules Contrave Reduces appetite and cravings  

For patients 18 years and older: 8 mg / 90mg – 32 mg / 360 mg capsules orally per day

≤4.1 kg (9 pounds) using maximum dose at 56 weeks 36% to 57% of patients met weight loss goal (≥5%) at 56 weeks compared to 17% to 43% with placebo

Can worsen depression and/or suicidal thoughts/behaviors Can cause seizures Can cause liver toxicity Can increase heart rate and blood pressure Can cause withdrawal symptoms in patients taking opiate medications Can cause vision changes Can cause low blood sugar in patients taking medication for diabetes Discontinuation rate: 1 out of 9 patients

Cost: ~$3/day  

Liraglutide injections Saxenda, Victoza glucagon-like peptide-1 receptor agonist to reduce appetite and food/calorie intake

For patients 12 years and older: 0.6 mg - 3 mg pen injections subcutaneously daily  

~3.7 to 5.2 kg (8.1 to 11.4 pounds) at maximum dose daily at 56 weeks   ~44% to 62% of patients met weight loss goal (≥5%) at 56 weeks compared to 16% to 34% with placebo.

Can cause severe nausea   Can cause pancreatitis   Can cause gallstones requiring surgery   Can cause kidney problems   Can cause low blood sugar in patients taking medication for diabetes Can cause vision problems in patients with diabetes Can worsen depression and/or suicidal thoughts/behaviors Risk of thyroid cancers Risk of fetal harm in pregnant patients Discontinuation rate: 1 out of 18 patients  

Cost: ~$45/day  

Semaglutide injections Wegovy, Ozempic glucagon-like peptide-1 receptor agonist to reduce appetite and food/calorie intake

For patients 12 years and older: 0.5 mg – 2.4 mg pen injections subcutaneously weekly  

~10.6 to 12.7 kg (22 to 27 pounds) at maximum dose  at one year2,10   67% to 85% of patients met weight loss goal (≥5%) at 52 weeks compared to 30% to 48% with placebo2,10

Can cause severe nausea   Can cause pancreatitis   Can cause gallstones requiring surgery   Can cause kidney problems   Can cause low blood sugar in patients taking medication for diabetes Can cause vision problems in patients with diabetes Can worsen depression and/or suicidal thoughts/behaviors Risk of thyroid cancers Risk of fetal harm in pregnant patients Discontinuation rate: 1 out of 18 patients  

Cost: ~$49/day or ~$340/week  

Tirzepatide injections Zepbound, Mounjaro glucagon-like peptide-1 receptor agonist to reduce appetite and food/calorie intake

For patients 18 years and older: 2.5 mg – 15 mg pen injections subcutaneously weekly  

22kg (48 pounds) at maximum dose at 72 weeks11   92% of patients met weight loss goal (≥5%) at 72 weeks compared to 34.5% with placebo11

Can cause severe nausea   Can cause pancreatitis   Can cause gallstones requiring surgery   Can cause kidney problems Can cause low blood sugar in patients taking medication for diabetes Can cause vision problems in patients with diabetes Can worsen depression and/or suicidal thoughts/behaviors Risk of thyroid cancers   Risk of fetal harm in pregnant patients Discontinuation rate: 1 out of 7 patients

Cost: ~$38/day or ~$265/week  


While it is true that the risk of infections, leaks, bleeding, blood clots, and injury to adjacent organs can be severe and are specific to surgery, weight-loss surgery has become very safe. The odds of the aforementioned risks are less than 5% for most healthy patients with obesity. Some patients report heartburn and reflux symptoms with a sleeve gastrectomy that is new or is worsened after surgery. In patients undergoing roux-en-y gastric bypass or duodenal switch, there is a risk of nutritional deficiencies, diarrhea, and internal hernias. It is common for patients to take a daily antacid medications and multivitamins after weight loss surgery. Extended-release formulations of medications often need to be switched to immediate-release formulations after surgery because the coating on the extended-release pills may not be broken down properly resulting in decreased absorption of the medication.

Note that dehydration, nausea, and vomiting can occur with either medications or surgery, so you need to drink lots of water with either treatment!

How long does it take for the weight loss medications vs. weight loss surgery to work? How long do they last? What if the treatment doesn’t help me lose enough weight?

Generally, medications and bariatric surgery both take about a year to see the full effects of the treatment with results noticeable in the first 3 months for the majority of patients. Studies show that patients often gain most of their weight back when medications are stopped. Surgery, on the other hand, has shown durability for weight loss at 2, 6, 10, and 20 years. Alternatively, weight loss medications can be switched or the dosage can be adjusted to achieve the intended weight loss. Surgery, unlike medications, is a permanent treatment and cannot be reversed. In some cases, weight loss surgery can be revised to achieve additional weight loss, though the amount of weight loss with revisional weight loss surgery is less predictable than primary (first time) weight-loss surgery.

How much experience does the medical community have with weight loss drugs vs. weight loss surgery?

It is tempting to think drugs are better than surgery to treat any given problem. After all, drugs are supposed to produce consistent and predictable effects. The reality is that data on GLP-1 agonists is extrapolated from thousands of patients over approximately 20 years, and the long-term effects are unknown. There is a wide range of weight loss (see the chart above) that the drugs can offer. Remember that these numbers are derived from clinical trial data which reflects a highly controlled environment in which study subjects had access to resources that may not be available to patients in the real world (ie. intense monitoring, robust lifestyle modification tools, free weight-loss coaching). In contrast, weight-loss surgery has been performed since the 1950s which means there is much more data on the long-term effects of surgical weight loss. In fact, the American Society of Metabolic and Bariatric Surgery (ASMBS), has collected data on over 1.6 million bariatric surgeries at 925 centers over the past decade which is publicly available and predicts the expected weight loss and risk for patients undergoing surgery.

What is the cost of weight loss drugs vs. surgery? Does insurance cover one or the other?

If insurance covers weight loss drugs, they are certainly going to be cheaper than surgery. However, many state-sponsored insurance plans including Medicare and Medicaid (in 33 of 50 states) do not cover weight loss drugs though they do cover weight loss surgery. The out-of-pocket cost of some of the oral medications is approximately $100 per month; the injectable GLP-1 agonists are closer to an exorbitant $1000 per month. Recent estimates from the ASMBS indicate surgery ranges from $17,000-$26,000. The total long-term costs of surgery could be comparable to those of medications, especially for patients on extended durations of GLP-1 agonist therapy.

What is required prior to getting weight-loss medications vs. surgery?

It may seem like weight loss medications are easier to obtain and less of a hassle than surgery. Some patients can remain in limbo for months to years due to insurance requirements, preoperative testing, or specialist doctors’ availability before finally getting weight loss surgery. Weight loss drugs may not require as extensive of workup as surgery; however, it is common to obtain bloodwork, ekgs, or even imaging before or during medical treatment (i.e. ultrasound of the gallbladder before starting GLP-1 agonists). Occasionally, clearances from specialists may be required prior to initiating therapy (i.e. consulting the cardiologist before starting phentermine products or consulting the psychologist before starting buproprion + naltrexone) like the process for weight loss surgery.

Are weight loss drugs readily accessible? What about weight loss surgery?

The reality is that there is a nationwide shortage of all the GLP-1 agonists, and it is expected to continue for the foreseeable future. This means that the pharmaceutical companies are not manufacturing the medications to meet the significant demand. Factor in the lack of widespread insurance coverage for weight loss drugs and the extra steps your doctor needs to take (prior authorizations) to get the drugs covered for the lucky few who do have coverage, and only fraction of people seeking medical weight loss actually end up starting treatment for an affordable price within a reasonable timeframe. While there is no shortage of surgeons performing weight loss surgery, some surgeons may not perform the specific procedure you are requesting. In this case, you may be referred to a reliable surgeon who does offer the procedure you are seeking, but travel may be necessary, especially in rural areas.

What is the deal with online “weight loss clinics” and online pharmacies? Are they legitimate? What about surgery overseas?

The frustrating roadblocks previously mentioned may drive some patients to seek weight loss medications from untrustworthy sources like online “weight loss clinics” specializing in obesity treatment or advertising medication at prices far cheaper than any brick-and-mortar pharmacy. Prices are cheaper because they may be sourcing the medication from unscrupulous distributors or partnering with pharmacies that compound (reformulate) the drugs. There is no guarantee that the compounding pharmacies are adhering to good manufacturing standards in sterile conditions, or even that the correct medication is being delivered without any harmful impurities or additives. There is currently minimal regulatory oversight of these online clinics and pharmacies, and it is easy to fake credentials or feign expertise to the unsuspecting patient. Be wary of these websites; if it sounds too good to be true, it probably is. The same is true for patients seeking surgery overseas to save money. Do not risk your life by settling for a surgeon that does not meet the standard of care in the US. The cost-savings are not worth it even if they are sizeable. Look for healthcare providers that have completed training at reputable institutions you may recognize. Check if their training is generalized or specifically in obesity. Ask your provider if they can provide proof of board certification in obesity medicine or surgery!

What is the “down time” after weight loss surgery? Is there any “down time” after starting the weight loss medications?

Weight loss surgery is generally performed in a minimally invasive approach, which reduces recovery time. Patients often walk in the recovery room immediately after surgery, and walk miles around the ward before being discharged the following day at our program. The patients are counseled to avoid lifting heavy weights for 4-6 weeks, but are able to resume light cardio and swimming after 2 weeks. There is usually no “down time” associated with drugs like there is with surgery. Nausea and diarrhea have been reported to debilitating in some instances for GLP-1 agonists requiring dosage adjustment or even discontinuation of therapy in up to 15% of patients. Often, these symptoms are transient and lessen in severity after the first few weeks.

Who is a candidate for weight loss medications vs. surgery?

Regardless of medications or surgery, a healthy diet and regular exercise should be the first steps in your weight loss journey. These lifestyle modifications should be incorporated in any treatment plan under the supervision of a multidisciplinary weight loss program.

Weight-loss medications can be considered in adolescents or adults with a BMI of 27.5 – 30 with obesity-related health conditions (i.e. diabetes, high blood pressure, high cholesterol, obstructive sleep apnea) or in people of Asian ethnicities. Adolescents or adults with a BMI of 30 or higher can benefit from weight loss medications regardless of whether obesity-related health conditions are present.

Avoid weight loss medications if you: do not wish to take medications for the long-term or cannot afford them, are concerned with weight regain after stopping the medications, or have a history of depression or suicidal thoughts unmonitored by a healthcare professional.

According to the ASMBS, weight loss surgery should be considered in people of Asian ethnicities with a BMI of 27.5 or higher, in patients with a BMI of 30 or higher and obesity-related health conditions or insufficient improvement with other weight-loss treatments, or any patients with a BMI of 35 or higher.

Avoid surgery if you: are deemed to be too high risk for anesthesia, plan on continuing to smoke after surgery, or are dependent on certain medications like ibuprofen or prednisone.

Each person faces unique medical, psychological, logistical, and spiritual challenges on their weight loss journey. Therefore, you need a personalized roadmap that you and your doctor specializing in obesity have created together. Remember that both weight loss medications and surgery are tools, not miracle cures and there is no replacing a healthy diet, regular exercise, and strong support system. If you’d like to know more, please feel free to schedule an in-person or virtual consultation!

Weight Loss Medications vs
Karan Grover

ABOUT THE AUTHOR

Karan Grover, MD, PharmD is a board-certified, fellowship-trained robotic and laparoscopic general surgeon with a specialization in minimally invasive bariatric and foregut surgery. Dr. Grover performs sleeve gastrectomy, roux-en-y gastric bypass, revisional bariatric surgery,endoscopic procedures, anti-reflux procedures, and hernia repairs at Advanced Surgical and Bariatrics of NJ.

ABOUT THE AUTHOR

Dr. Sadek is a board-certified, fellowship-trained robotic and laparoscopic general surgeon with a specialization in minimally invasive bariatric and foregut surgery. A clinical assistant Professor of surgery at Rutgers RWJ Medical School and the Director of bariatric surgery program at RWJ Barnabas University Hospital, as well as the system wide chief of minimally invasive and bariatric surgery at Robert Wood Johnson Barnabas Healthcare system. Dr. Sadek has founded and established one of the largest, safest, state-of-the-art bariatric surgery programs in the northeast.