Mounjaro vs. Qsymia for Weight Loss

Explore the dynamic world of prescription weight loss medications, comparing Mounjaro and Qsymia. This guide aims to assist in choosing the right medication for your weight loss journey, highlighting benefits and considerations for each.

Table of Contents
  • Mounjaro
  • Metformin
  • Comparing Mounjaro and Metformin
  • Effectiveness
  • Administration and Dosage
  • Adverse Effects
  • Cost and Coverage
  • Where Can I Find These Medications?

Mounjaro (Tirzepatide)

Mounjaro is a new medication that belongs to the GLP-1 agonist family of anti-diabetic medications. It has been gaining popularity for its off-label use for weight loss and obesity. It is a GLP-1, GIP, and glucagon triple agonist that works by targeting multiple hormones that regulate appetite and metabolism. Mounjaro has shown promising results in clinical trials, with patients experiencing significant weight loss in over a year combined with exercise and diet (1).

Mounjaro is administered once a week via a subcutaneous injection. The duration of therapy depends on the patient’s goals, but the most significant effects were studied over a 72-week (~1.4 years) period (1). 

The most common side effects of Mounjaro reported in clinical trials include gastrointestinal symptoms such as nausea (24%), vomiting (8%), and diarrhea (18%) (1). However, these side effects were mild to moderate and usually resolved within a few days.

Qsymia (Phentermine/Topiramate) 

Qsymia is a prescription weight loss medication that contains a combination of two drugs: phentermine and topiramate. Phentermine is an appetite suppressant that affects the central nervous system and helps to reduce food cravings. Topiramate is an anti-seizure drug that can also help with weight loss by reducing appetite and increasing feelings of fullness. It also increases the effects of phentermine. Together, these drugs work to help people lose weight by reducing their calorie intake and increasing their metabolism. Qsymia is FDA-approved d for people with a body mass index (BMI) of 30 or higher or those with a BMI of 27 or higher and at least one weight-related condition such as high blood pressure, diabetes, or high cholesterol.

Qsymia is a once-daily oral capsule taken in the morning. The dose starts low at 3.75mg/23mg then increases to 7.5mg/46mg after two weeks. The dose can be steadily increased after 12 weeks based on your response to the therapy.  

The most common side effects of Qsymia include numbness or tingling in the hands, arms, feet, or face (paraesthesia); dizziness; changes in the way foods taste or loss of taste (dysgeusia); trouble sleeping (insomnia); constipation and dry mouth. 

Qsymia should be avoided if you are pregnant or planning to become pregnant as it can cause birth defects in early pregnancy, such as cleft lip and cleft palate. Qsymia should also be avoided if you have glaucoma or a history of tachycardia or arrhythmias. Qsymia is also an FDA controlled substance and has the potential to cause addiction and drug abuse. 

Comparing Mounjaro and Qsymia

Here are some critical differences between Mounjaro and Qysemia when used for weight loss that you should consider before starting either of these medications


Both medications have shown great promise when managing obesity and assisting people with weight loss. It should always be noted that the best results are seen in combination with dieting and regular exercise. 

For Mounjaro, The SURMOUNT-1 trial published in 2022 was a large clinical trial with over 2500 participants that looked at how effective Mounjaro (tirzepatide) was at managing obesity (1). Mounjaro was given at different doses for a period of 72 weeks to groups of non-diabetic participants who were struggling with obesity. The participants also did a calorie restriction diet (500 kcal/day), did 150 minutes of exercise per week, and had regularly scheduled with a dietician. 

The results of this trial were very exciting for doctors in the field of obesity medicine. They found that after 72 weeks, each group that was taking Mounjaro showed significant weight loss compared to the placebo group. Each treatment group experienced a 15-20% change in weight from the start of the trial, with higher doses showing a more remarkable change. 

For Qsymia, the CONQUER Trial that was published back in 2011 studied the effect of low-dose Qsymia on weight and associated conditions for overweight and obese patients. The study was done over a 52-week period where participants took different doses of Qysemia from 7.5mg/46mg to 15mg/92mg and looked at how their weight changed. They saw that people on 7.5 mg of Qysemia saw a 7.8% decrease, and this was seen without regular dieting and exercise! They also saw that around 68% of people noticed at least a 5% reduction in weight after one year (2). 

When comparing the two studies, there are a few things to note. Mounjaro had a more significant percentage of participants who saw at least a 5% reduction in weight in one year. There may be an even greater weight loss effect if Qsymia is paired with diet and exercise that matches Mounjaro.

Administration and Dosage

The dosage and administration of Qsymia and Mounjaro are very different. Mounjaro is a once-weekly injection that starts at a low dose of 2.5mg and can gradually increase over time. 

Qsymia is a once-daily oral capsule that is taken in the morning. It starts at a low dose of 3.75mg for two weeks, then it is increased to 7.5mg, which is the recommended dose for weight loss. This more extended titration period may delay the weight loss effects you want. However, taking a pill may be more convenient than an injection if you are averse to injections.

Side Effects

The most common side effects of Mounjaro are nausea, vomiting, diarrhea, and stomach aches. These are often mild to moderate in severity and are dependent on the dose. They are also often transient and disappear over time. Mounjaro should be avoided if you have a history of pancreatitis, gallbladder disease, diabetic retinopathy, history of medullary thyroid cancer or family history of Multiple Endocrine Neoplasia Cancer Syndrome Type 2 (MEN-2). Mounjaro should also be avoided if you have had low blood sugar (hypoglycemia) episodes or are currently taking insulin. 

The side effects of Qsymia are numbness and tingling in the extremities, dizziness, changes in taste, difficulty sleeping, mood changes, constipation, and dry mouth. Qsymia can also cause suicidal thoughts and is used with caution in people with suicidal depression. Qysmia can increase heart rate and should be avoided if you have tachycardia or any heart arrhythmias. Qsymia should not be used if you are pregnant or planning to become pregnant due to birth defects. 

Cost and Coverage

Unfortunately, Mounjaro can be very expensive, depending on your insurance. The average cost for a month's supply of Mounjaro can range from $900-$1000. Depending on your insurance plan, you may also be eligible for the Mounjaro Savings Card, which can allow you to pay as little as $25 per month for Mounjaro. To see if you are eligible for the Mounjaro Savings Card, click on the link to go to the official website. Complete the online savings program enrollment form to see if you can get set up with the savings card and save yourself a lot of money. 

Mounjaro is not currently FDA-approved for the management of obesity, which may make finding coverage by insurance difficult. You may be eligible if you have type 2 diabetes. Ultimately, you should contact your insurance company to see if you are eligible for coverage of Mounjaro and what steps need to be taken to receive coverage. There are also compound forms of Mounjaro that you can get at a lower monthly price. If you would like to know more about compound options for Mounjaro, check out our website at Mochi Health

The average retail cost for Qsymia is around $250 for a month's supply. Since Qysmia has been on the market for some time and has been approved for weight loss, it is more likely to be covered by insurance. The is also a Qysmia Savings Card where you can pay up to $70 for the first copay, and then the card covers up to $65 of the remaining cost. 

Where Can I Get These Medications?

If you would like to learn more about GLP-1 medications or want to see if you might be eligible for medication-assisted weight loss, check out Mochi Health, where board-certified obesity medicine physicians can offer expertise in this realm!


  1. Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, Kiyosue A, Zhang S, Liu B, Bunck MC, Stefanski A; SURMOUNT-1 Investigators. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022 Jul 21;387(3):205-216. doi: 10.1056/NEJMoa2206038. Epub 2022 Jun 4. PMID: 35658024.
  2. Gadde KM, Allison DB, Ryan DH, Peterson CA, Troupin B, Schwiers ML, Day WW. Effects of low-dose, controlled-release, phentermine plus topiramate combination on weight and associated comorbidities in overweight and obese adults (CONQUER): a randomised, placebo-controlled, phase 3 trial. Lancet. 2011 Apr 16;377(9774):1341-52. doi: 10.1016/S0140-6736(11)60205-5. Epub 2011 Apr 8. Erratum in: Lancet. 2011 Apr 30;377(9776):1494. PMID: 21481449.

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