Compounded Tirzepatide vs Zepbound: A Factual Comparison

With Zepbound costing $1,000+ per month without insurance, many patients are exploring compounded tirzepatide as an alternative. But what exactly are the differences? Here's a factual comparison to help you understand your options.

Quick Comparison

What is Zepbound?

Zepbound is the brand name for tirzepatide, manufactured by Eli Lilly and FDA-approved specifically for chronic weight management. It was approved in November 2023 for adults with obesity (BMI ≥30) or overweight (BMI ≥27) with at least one weight-related condition.

In clinical trials, tirzepatide showed significant weight loss results. Participants lost an average of 15-21% of their body weight over 72 weeks, depending on the dose. This made Zepbound one of the most effective weight-loss medications ever approved.

Zepbound comes as a pre-filled, single-dose pen that's injected once weekly. The convenience of the pen format eliminates the need for patients to draw their own doses from vials.

What is Compounded Tirzepatide?

Compounded tirzepatide contains the same active pharmaceutical ingredient (API) as Zepbound, but it's prepared by a compounding pharmacy rather than manufactured by Eli Lilly. Compounding pharmacies legally make custom medications when there's a legitimate need, such as during drug shortages or to create alternative formulations.

Unlike Zepbound's pre-filled pens, compounded tirzepatide typically comes in multi-dose vials. Patients must draw each dose using a syringe, which requires accurate measurement to avoid dosing errors.

The Regulatory Situation

The Shortage That Ended

Tirzepatide was on the FDA's drug shortage list until October 2024. During this shortage period, compounding pharmacies could legally produce tirzepatide under Section 503A of the Federal Food, Drug, and Cosmetic Act, which permits compounding of drugs that are in shortage.

When the shortage ended, the FDA announced a transition period. That grace period ended on March 19, 2025, after which compounding of exact copies of tirzepatide was no longer permitted.

The "Significant Difference" Loophole

However, compounding hasn't stopped entirely. Under FDA regulations, pharmacies can still compound a version of a drug if the compounded product is "significantly different" from the commercially available version. Many compounding pharmacies now add ingredients like B12, L-carnitine, or other nutrients to their tirzepatide formulations to create this "significant difference."

This regulatory gray area means compounded tirzepatide remains available, but its long-term legal status is uncertain and could change if the FDA takes enforcement action.

Safety Considerations

FDA-Approved Manufacturing

Zepbound is manufactured in FDA-inspected facilities following current Good Manufacturing Practices (cGMP). Every batch undergoes rigorous testing for potency, purity, and sterility before being released to market. The pre-filled pen format also eliminates patient dosing errors.

Compounding Quality Varies

Compounded tirzepatide quality depends heavily on the specific pharmacy. The FDA has found significant potency variation in compounded GLP-1 products, with some samples testing between 42% and 170% of labeled strength.

There are two types of compounding facilities with different oversight levels:

• 503A pharmacies: State-regulated, prepare medications for individual prescriptions
• 503B outsourcing facilities: FDA-registered, follow cGMP standards, can produce larger batches

If choosing compounded tirzepatide, 503B facilities generally provide more consistent quality due to their FDA registration and manufacturing standards.

Dosing Error Risk

One significant safety difference: compounded vials require patients to draw their own doses. The FDA has documented reports of dosing errors with compounded GLP-1 vials, including cases where patients accidentally administered 5-20 times the intended dose. This has led to hospitalizations for severe nausea, vomiting, and dehydration.

Zepbound's pre-filled pen eliminates this risk entirely, as each pen contains exactly one dose.

Price Comparison

Zepbound Pricing

Without insurance, Zepbound costs approximately $1,000 per month or more. Eli Lilly has introduced lower-cost vial options through LillyDirect, starting at $349/month for the 2.5mg dose, but these are still significantly more expensive than compounded alternatives.

With insurance coverage (which is not guaranteed), out-of-pocket costs can be much lower, but many insurance plans don't cover weight-loss medications or require extensive prior authorization.

Compounded Tirzepatide Pricing

Compounded tirzepatide typically costs $199-450 per month through telehealth providers. Prices vary based on dosage, provider, and whether additional ingredients are included in the formulation.

This price difference – often $500-800 per month – is the primary reason many patients choose compounded versions despite the FDA approval status.

When to Consider Each Option

Consider Zepbound If:

• • Your insurance covers it with reasonable copays
• • You want the assurance of FDA-approved manufacturing
• • You prefer the convenience of pre-filled pens
• • You're uncomfortable with the regulatory uncertainty around compounding
• • You can afford the higher cost

Consider Compounded Tirzepatide If:

• • Cost is a major barrier to treatment
• • You don't have insurance coverage for brand-name medications
• • You're comfortable with the additional steps of drawing doses from vials
• • You choose a provider with verified pharmacy credentials (503B, LegitScript, PCAB)
• • You understand and accept the regulatory uncertainty

Making Your Decision

There's no universally "right" choice between compounded tirzepatide and Zepbound. The decision depends on your financial situation, risk tolerance, and access to insurance coverage.

If you choose a compounded option, prioritize providers that work with 503B outsourcing facilities, hold LegitScript certification, and provide transparent information about their pharmacy partners. The cost savings aren't worth it if you can't verify the quality and legitimacy of what you're receiving.

Regardless of which option you choose, tirzepatide should only be used under the supervision of a licensed healthcare provider who can monitor your progress and adjust treatment as needed.