Tirzepatide for Prediabetes: Off-Label and Insurance

The approval language for tirzepatide is precise: Mounjaro is for type 2 diabetes, Zepbound is for chronic weight management in adults with obesity or overweight. Prediabetes — an HbA1c between 5.7% and 6.4%, or a fasting glucose of 100–125 mg/dL — fits neatly into neither box. Yet the SURMOUNT-1 trial produced the most striking prediabetes reversal data any pharmaceutical trial has ever generated, and a growing number of people in the 5.7–6.4% HbA1c range are now asking whether tirzepatide for prediabetes makes clinical sense.

The short answer: the biology is compelling, the off-label prescribing path is navigable, and insurance is the main friction point.

What SURMOUNT-1 actually showed

SURMOUNT-1 was the pivotal weight-management trial for tirzepatide (the molecule behind Zepbound). It enrolled 2,539 adults with obesity or overweight and without type 2 diabetes — but 95.3% of enrolled participants had prediabetes at baseline. That makes SURMOUNT-1, alongside being a weight trial, one of the largest prospective prediabetes intervention datasets ever collected.

The results at 72 weeks were striking. On 15 mg tirzepatide, participants lost a mean of 22.5% of body weight. Among the prediabetes subgroup, approximately 90% reverted to normal blood glucose — HbA1c below 5.7% — by week 72 on the highest dose. Even on 5 mg, roughly 70% of participants with prediabetes at baseline achieved normoglycemia.

To appreciate how unusual this is: the gold-standard lifestyle intervention for prediabetes — the Diabetes Prevention Program lifestyle arm, on which the CDC's Prevent T2 curriculum is based — achieved a 58% reduction in progression to T2D over three years. Tirzepatide isn't just slowing progression; it appears to be reversing glucose dysregulation entirely in the majority of people who try it.

The mechanism isn't only weight loss. Tirzepatide is a dual GLP-1/GIP receptor agonist, and GIP specifically improves insulin sensitivity at adipose tissue in ways that GLP-1 agonism alone doesn't. People with prediabetes have an early-stage insulin resistance problem, and tirzepatide addresses it at two receptor pathways simultaneously. The detailed mechanism is in our how tirzepatide works cluster.

Why it's technically off-label

Mounjaro's FDA indication is adults with type 2 diabetes. Zepbound's indication is adults with BMI ≥30, or BMI ≥27 with at least one weight-related comorbidity (hypertension, dyslipidemia, type 2 diabetes, obstructive sleep apnea, or cardiovascular disease).

Prediabetes is not type 2 diabetes. And while prediabetes might qualify as a weight-related comorbidity for Zepbound in some clinical interpretations, the label doesn't list it explicitly, and an insurer reading the label strictly will deny coverage on those grounds.

Off-label prescribing is legal and common in the United States. Roughly 20% of all prescriptions written are off-label. Clinicians can legally prescribe tirzepatide for prediabetes prevention if they have clinical justification. The question is whether your insurance will pay for it.

How insurance handles prediabetes use

Commercial insurance and prior authorization

Most commercial plans cover Mounjaro for T2D with prior authorization. Zepbound coverage for weight management is expanding but still uneven — in 2025, fewer than half of large employer-sponsored plans covered GLP-1s for obesity, though that number is rising.

For prediabetes specifically, you need your insurer to approve a drug for an indication that doesn't match the label. That requires:

1. A letter of medical necessity from your prescriber explaining the clinical rationale — SURMOUNT-1 data, HbA1c trajectory, documented family history, and explicit T2D prevention intent
2. Documentation that lifestyle modification was attempted or is insufficient alone
3. Often, a formal appeal if the initial prior authorization is denied

Appeals are worth filing. Studies of denied insurance claims find that 40–50% of properly documented appeals succeed, especially when a physician is involved and the appeal cites clinical evidence.

Some commercial insurers have begun reading Zepbound's "weight-related comorbidity" language broadly enough to include prediabetes, particularly when the prescriber explicitly documents the comorbidity and the patient has a BMI ≥27. If your plan has updated its formulary to include obesity as a covered condition, this is the angle most likely to succeed.

Medicare and Medicaid

Medicare Part D covers Mounjaro for T2D under its standard drug benefit but does not cover Zepbound for weight management under the current law (the Treat and Reduce Obesity Act, which would add coverage, has not passed as of recent sessions). For prediabetes prevention, there is no established Medicare coverage pathway.

Medicaid coverage varies significantly by state. A handful of states have expanded GLP-1 access for obesity; most have not. Check your state Medicaid formulary directly.

Compounded tirzepatide as a bridge

If insurance is a dead end, compounded tirzepatide from a 503B pharmacy typically costs $200–$500 per month depending on dose — roughly one-quarter the list price of Zepbound. For someone using tirzepatide on a finite timeline to reverse prediabetes (12–18 months, then reassess), this is a cost some patients are willing to absorb. The vetting criteria for safe compounded tirzepatide are in our compounded tirzepatide guide.

Making the risk-benefit case: who this is for

Not every person with an HbA1c of 5.7% needs to consider a GLP-1. The clinical math changes depending on trajectory and risk factors.

The American Diabetes Association's 2024 Standards of Care note that GLP-1 receptor agonists "may be considered" for T2D prevention in high-risk prediabetes, though they're not currently a first-line recommendation. This is the kind of nuanced language that changes over time — the guideline is moving in one direction.

What to bring to the conversation with your doctor

If you want to make a case for tirzepatide for prediabetes, come prepared:

• Two or three HbA1c readings showing trajectory (not just one number)
• BMI and waist circumference (adds clinical weight to the comorbidity argument)
• Family history of T2D (first-degree relatives)
• Evidence of lifestyle effort: dietary changes tried, exercise history, weight trend
• Willingness to commit to a trial: a 12-month course with HbA1c retesting at 3 and 6 months is a reasonable proposal

The specific trial to reference is Jastreboff et al., "Tirzepatide Once Weekly for the Treatment of Obesity," New England Journal of Medicine, 2022 — particularly the prediabetes subgroup data in the supplementary appendix.

If coverage is denied, ask your prescriber whether they'll submit a prior authorization letter citing the SURMOUNT data and T2D prevention intent. A well-written letter from a physician carries weight in the appeals process.

See also:

• Mounjaro vs. Zepbound: what the two approvals mean for you
• Tirzepatide vs. semaglutide head-to-head
• SURMOUNT trial results decoded
• How tirzepatide works as a dual agonist

Related reading

• Tirzepatide complete guide
• Weight loss: realistic timelines
• GLP-1 side effects overview