Zepbound vs. compounded semaglutide for weight loss

Which prescription weight loss medication is best for your body, biology, and budget? That’s the million-dollar question. 

At Found, our MetabolicPrint™ evaluation helps remove some of the guesswork, and prescriptions, which are always up to a provider’s discretion, are matched to your unique needs. But a side-by-side comparison can be enlightening, especially if you’re already eyeing a couple of options. 

It’s smart to consider how each drug works, what potential side effects and risks they carry, how much they cost, and whether your insurance covers them.  

Here, we’re comparing two drugs for weight loss, Zepbound® (tirzepatide) vs. compounded semaglutide. Let’s see how they stack up.‍

What is Zepbound and how does it work?

Zepbound is a prescription medication for chronic weight management approved by the U.S. Food & Drug Administration (FDA) in November 2023. Made by Eli Lilly, it’s indicated for adults with obesity and those with excess weight who have at least one weight-related health condition (like high blood pressure or high cholesterol). Zepbound’s a once-weekly injection paired with a reduced-calorie diet and increased physical activity.

The active ingredient in Zepbound is tirzepatide which is also in Mounjaro®, a Lilly medication for those with type 2 diabetes. This “dual agonist” works by simulating not one but two gut hormones: glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). These naturally occurring hormones help regulate blood sugar, stomach-emptying, and appetite, reducing cravings and improving satiety, which helps people eat less, feel fuller longer, and lose weight. 

What is semaglutide and how does it work?

Semaglutide is the active ingredient in the FDA-approved prescription drugs Ozempic® (for type 2 diabetes) and Wegovy® (for weight loss). Manufactured by Novo Nordisk, both of these brand-name drugs are also taken as a once-weekly injection.

Semaglutide is a single agonist—and more specifically a GLP-1 receptor agonist. It mimics the body’s GLP-1 hormone to help regulate blood sugar levels, improve satiety (fullness after eating), and lose weight. Studies have found semaglutide can also reduce the risk of heart attack, stroke, and other serious cardiovascular events in people with excess weight and previously diagnosed heart disease or those with type 2 diabetes and a risk of cardiovascular disease.

Compounded semaglutide is semaglutide made by a licensed compounding pharmacy or pharmacist or by an FDA-regulated outsourcing facility—rather than by the manufacturer of the FDA-approved drugs.

To be clear: Compounded drugs are not FDA-approved or evaluated by the FDA for safety or efficacy. However, they are permitted by the FDA in certain circumstances, such as when an individual patient needs a slightly different formulation of an FDA-approved drug or when the FDA-approved medication is on the FDA Drug Shortages list—as some doses of Wegovy and Ozempic have been, off and on, since 2022.

Zepbound (tirzepatide) vs compounded semaglutide vs Wegovy (semaglutide): How much weight can you lose—and how fast?

Individual results vary, and it’s impossible to predict whether or how quickly a drug might work for you. But research offers some clues.

In a clinical trial of Zepbound published in JAMA in January 2024, people taking the two highest doses (10 mg and 15 mg) of injectable tirzepatide each week, along with lifestyle changes, lost an average of 20.9% of their body weight in 36 weeks (about nine months). Those who continued taking the drug for another year maintained that weight loss—and, on average, lost an additional 5.5%. The study involved adults with obesity (defined as having a body mass index, or BMI, of 30 or more) and people with overweight (a BMI of 27+) without type 2 diabetes. 

In a premarket clinical trial for Wegovy, people with obesity and people who were overweight with a weight-related health condition were given weekly semaglutide injections along with diet and exercise recommendations. They achieved an average loss of 15% of their body weight in 68 weeks (about a year and 4 months).

A cohort study published in JAMA Internal Medicine in July 2024 examined the electronic medical records of more than 18,000 patients with excess weight or obesity who were prescribed either tirzepatide or semaglutide (in formulations labeled for type 2 diabetes) for weight loss, whether or not they had type 2 diabetes. Researchers found that, on average, patients on tirzepatide lost 2.4% more weight at three months, 4.3% more weight at six months, and 6.9% more weight at 12 months than those on semaglutide did.

It’s unclear whether compounded semaglutide (versions of semaglutide created by compounding pharmacies during drug shortages or variations adapted for individual patient needs) would have achieved the same results. And there are no head-to-head trials that compare compounded semaglutide to Zepbound. Compounded semaglutide is not FDA- approved or evaluated for safety or efficacy.

Zepbound vs compounded semaglutide vs Wegovy: How much do they cost per month?

Without insurance coverage or coupons, the cost of four weekly injector pens of any dosage of Zepbound was running between $1,200 and $1,300 in recent retail price checks in some locations. (The wholesale list price is about $1,060, but pharmacy prices can typically be up to 20% higher.) The manufacturer’s savings card or coupon can cut the cost to $650 for those with commercial health insurance that doesn’t cover Zepbound—or to as little as $25 a month for those with insurance that does. 

The two lowest Zepbound dosages (2.5 mg and 5 mg) are also available in vials from Lilly Direct for $399 or $549 a month, respectively. The vials require users to draw up and inject the medication with a needle-tipped syringe, and the vial price cannot be paired with insurance or discounts.

Advertised prices for injectable compounded semaglutide varied in recent checks but were typically less than $300 for a one-month supply (compared to retail prices for Wegovy, which has a list price of about $1,350 but was retailing in some locations for $1,580 and $1,650 in October 2024 without insurance). Many insurers do not cover compounded medications. 

At Found, compounded semaglutide costs $189, including shipping, for a 28-day supply (four weekly doses in vials). That doesn’t include the cost of clinical visits, labs or a Found subscription—which provides access to a health coach, as well as lifestyle change education and support from a community of fellow Found members within the Found app.

Tirzepatide vs semaglutide: Common side effects & warnings 

The most commonly reported side effects for tirzepatide (Zepbound and Mounjaro) and semaglutide (Wegovy and Ozempic) are stomach and gastrointestinal issues (such as nausea, vomiting, diarrhea, constipation, and abdominal pain). These often occur when patients start taking the medication or are transitioning to a higher dose. 

More serious side effects reported for both drugs include pancreatitis, gallbladder disease, acute kidney injury, gastroparesis (stomach paralysis), hypoglycemia, suicidal behavior or ideation, and worsening of diabetic eye disease. Both carry FDA “black box” warnings about thyroid cancer: Those with a personal or family history of medullary thyroid cancer (MTC) or multiple endocrine neoplasias should not use Zepbound or semaglutide. Nor should women who are planning to become pregnant or are pregnant or breastfeeding. This isn’t a complete list of risks or side effects, but you can find more for specific drugs by name on our dedicated medication page.

While all drugs present some risk, compounded medications like compounded semaglutide come with additional safety concerns: 

1. The FDA does not review compounded medications for safety, efficacy, or quality. Although a compounded drug must contain the active ingredient it promises, its exact formulation, dosage, potency, ingredient combination, and side effects may differ from that of an FDA-approved brand-name or generic drug. 
2. Poor practices at an outsourcing facility or a pharmacy that is compounding semaglutide may result in serious issues with quality—including medication that’s contaminated or contains too much or too little of the active ingredient. 
3. Self-dosing errors can happen more commonly with drugs that are dispensed in vials with separate syringes and needles (as compounded semaglutide injections typically are),  rather than in prefilled injector pens. There have been serious dosing errors reported with compounded semaglutide use. Patients whose weight loss medications come in vials must take care to avoid drawing up or injecting the wrong amount.
4. And for compounded semaglutide in particular, the FDA has received reports of illegal counterfeits. These include the salt forms of semaglutide, such as semaglutide sodium or semaglutide acetate, masquerading as legally compounded semaglutide or FDA-approved Wegovy or Ozempic. So, it’s important to ask exactly what’s in any compounded medication you take.

So, which is better for you: Zepbound, compounded semaglutide, or Wegovy? 

In truth, no medication is right for everyone. And just because one treatment proves more effective than another in clinical settings doesn’t mean it will be the one that works best—or is  the most sustainable—for you. 

That’s why getting your unique MetabolicPrint, designed by the obesity medicine specialists at Found, can be so helpful. It begins with this simple quiz.‍

About Found

Found is among the largest medically-supported telehealth weight care clinics in the country, having served more than 250,000 members to date. To discover your MetabolicPrint™ and start your journey with Found, take our quiz. 

While GLP-1s and tirzepatide are effective for weight loss, they are not clinically appropriate for everyone. Eligibility for these drugs is based on a provider’s evaluation of your medical history, MetabolicPrint, and lab work. If these drugs are not appropriate for you, a provider will work with you to determine an effective medication for your health profile.

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