Same molecule, different product. Zepbound and compounded tirzepatide share an active ingredient, and that's where the overlap ends. Approval, oversight, ingredients, devices and evidence all differ. The table below lays it out; the sections after it explain each row. For the basics of the compounded drug, see our compounded tirzepatide guide.
| Attribute | Zepbound | Compounded tirzepatide |
|---|---|---|
| FDA-approved? | Yes (NDA 217806, November 2023) | No |
| Who makes it | Eli Lilly, under its approved application | A state-licensed compounding pharmacy, per prescription |
| Approved uses | Weight reduction in adults with obesity, or overweight plus a related condition; moderate to severe sleep apnea with obesity | None |
| Forms | Single-dose pens and vials; 4-dose vials and KwikPen; 2.5 mg to 15 mg | Usually multi-dose vials; strength varies by pharmacy |
| Ingredients | Tirzepatide plus listed excipients | Tirzepatide, sometimes with B12, B6 or glycine added |
| Trial evidence | SURMOUNT trials, e.g. −20.9% average weight at 15 mg, 72 weeks | None |
| FDA quality review before sale | Yes | No |
| Adverse-event reports | Collected under standard drug-safety reporting; side effects listed on the label | More than 730 reports to FDA as of May 31, 2026; likely underreported |
| Self-pay price | LillyDirect: $299 (2.5 mg), $399 (5 mg), $449 (7.5–15 mg, refilled within 45 days) | $85–$399/mo at telehealth programs |
| Prescription needed? | Yes | Yes |
| Insurance | Possible, depending on plan and diagnosis | Generally not covered |
Zepbound rows draw on its DailyMed prescribing information (version 40) and Drugs@FDA. The compounded price range reflects provider sites, and the brand prices reflect LillyDirect, both as of this update.
Zepbound went through FDA review; compounded tirzepatide never does
FDA approved Zepbound on November 8, 2023 [3], and Mounjaro, Lilly's tirzepatide for type 2 diabetes, on May 13, 2022 [4]. Approval means FDA reviewed the trial data, the manufacturing and the label before either drug was sold.
Compounded drugs skip that step. In FDA's words, compounded drugs "are not FDA approved," so the agency never checks a compounded product's safety, effectiveness or quality ahead of sale. It adds that they should be used only when a patient's needs can't be met by an approved drug [5].
Since the shortage ended, the legal room is narrow. A state-licensed pharmacy may compound tirzepatide for an individual patient, but routine copies of Zepbound aren't allowed unless a prescriber documents that the compounded version makes a significant difference for that patient [6]. The guide to whether compounded tirzepatide is still available covers the timeline.
What's in each: a listed formula vs whatever the pharmacy adds
Zepbound's label lists exactly what's in it. Single-dose pens and vials contain tirzepatide with sodium chloride, sodium phosphate and water. The 4-dose vial and KwikPen add preservatives, including benzyl alcohol and phenol, plus glycerin [1]. The label identifies the active ingredient simply as tirzepatide.
Compounded versions vary. Many add vitamin B12, B6 or glycine. When researchers posed as patients at 75 clinics and med spas in West Virginia and Oklahoma in 2025, 56% offered GLP-1s mixed with B vitamins [11]. Those add-ins have never been tested with tirzepatide in a trial.
One 2026 lab study tested compounded tirzepatide-B12 products bought in the U.S. and found a previously unknown impurity formed by a reaction between tirzepatide and some forms of B12. Its clinical effects are unknown [10]. The authors are Eli Lilly scientists, so read it as the brand maker's own testing.
Zepbound comes as fixed doses; compounded vials need measuring
Zepbound comes in single-dose pens and vials and in 4-dose vials and KwikPens, each at one strength from 2.5 mg to 15 mg [1]. You get the dose printed on the pen or vial.
Compounded tirzepatide usually ships in multi-dose vials whose strength depends on the pharmacy, so the amount you draw changes with the vial. FDA has adverse-event reports linked to dosing errors with compounded GLP-1s, and it recommends using multi-dose vials within 28 days of first use [5]. Doses themselves are your prescriber's call; the starting dose guide explains what the label says.
Zepbound has the evidence; compounded tirzepatide has none of its own
SURMOUNT-1 is the trial behind Zepbound's weight-loss approval. Over 72 weeks, average weight loss was 15.0% on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg, against 3.1% for placebo [8]. That's the evidence people quote for tirzepatide.
Those results belong to Lilly's product, made to its approved specifications. No compounded tirzepatide has been tested in a trial. So the honest answer to "is Zepbound better?" is that Zepbound is the one with evidence. Whether a given compounded product performs the same is unknown.
Safety: the same label warnings, plus compounding risks
Because the molecule is the same, Zepbound's warnings apply to compounded tirzepatide too. That includes the boxed warning about thyroid C-cell tumors seen in rodents, and the label's warnings on stomach side effects [1].
Compounding adds its own risks. As of May 31, 2026, FDA had received more than 730 adverse-event reports tied to compounded tirzepatide, and it says these are likely underreported because most compounding pharmacies don't have to report them [5]. FDA has also found fraudulent products whose labels name pharmacies that don't exist, or real pharmacies that didn't make them.
Cost: the gap is smaller than it was
Compounded tirzepatide used to cost a fraction of the brand. Lilly's own self-pay prices currently start at $299 a month at the 2.5 mg starting dose, rise to $399 at 5 mg, and top out at $449 from 7.5 mg up, as long as each refill comes within 45 days [7]. Miss that window and the regular prices apply: $499 for 7.5 mg and $699 for 10 mg and above. Needles are bought separately.
| Option | Starting dose | Higher doses | Notes |
|---|---|---|---|
| Zepbound via LillyDirect | $299 a month (2.5 mg) | $399 (5 mg); $449 (7.5–15 mg) | $449 needs a refill within 45 days; otherwise $499–$699 |
| Compounded, telehealth programs | $85–$399/mo | Often the same price at every dose | Not FDA-reviewed |
Program prices from each provider's own site on each provider's site; brand-access rows show the program's headline monthly cost including its fee.
Also offered by (no standing monthly price published): Zepbound via Shed.
At the starting dose, some compounded plans still cost less than LillyDirect. At maintenance doses the comparison depends on the program, since many compounded plans charge one price at every dose. The compounded tirzepatide cost guide has every program's price, and compounded tirzepatide programs, scored compares them on more than price.
Mounjaro vs Zepbound vs compounded: one molecule, three products
Mounjaro and Zepbound are both Lilly's tirzepatide. Mounjaro is labeled to improve blood sugar in adults and children 10 and older with type 2 diabetes, and to lower the risk of major heart events in adults with type 2 diabetes at high risk for them [2]. Zepbound is labeled for weight reduction and for obstructive sleep apnea with obesity [1]. Compounded tirzepatide has no labeled use.
Semaglutide is a different molecule altogether. In SURMOUNT-5, a Lilly-funded open-label trial of 751 adults with obesity, tirzepatide at its top tolerated dose produced 20.2% average weight loss at 72 weeks versus 13.7% for semaglutide [9]. For semaglutide itself, see our compounded semaglutide guide, and for the brand matchup, Zepbound vs Wegovy.
Switching between them is a prescriber decision
If you want to move from compounded tirzepatide to Zepbound or back, talk to your prescriber first. The labels offer no conversion for compounded products, and a different vial strength changes how a dose is measured. Zepbound's label does describe a step-up schedule from 2.5 mg, which some prescribers use as the reference point when restarting [1].
If you're still choosing a source, how to get compounded tirzepatide legally walks through the routes and the checks.