Baloxavir Marboxil Shortage: A Provider's Update for the 2025-2026 Flu Season

Healthcare providers across the country have increasingly encountered challenges with Baloxavir Marboxil (Xofluza) availability during the 2025-2026 influenza season. While Xofluza has not been formally listed on the FDA Drug Shortage Database, real-world pharmacy-level stock-outs have affected patient care and prescribing workflows. This article provides a clinical summary of the current supply landscape, contributing factors, and practical guidance for prescribers.

Current Supply Status

As of early 2026, Baloxavir Marboxil remains available from its sole manufacturer, Genentech (Roche), but distribution has been uneven across regions. Pharmacies—particularly community and independent pharmacies—have reported intermittent stock-outs during periods of peak influenza activity. Large retail chains have generally maintained better inventory levels, though localized shortages have been documented even at major pharmacy chains in high-demand areas.

The shortage pattern mirrors those seen during the 2022-2023 and 2023-2024 influenza seasons, when similar demand-driven gaps occurred. Genentech has not issued formal communications indicating manufacturing or supply chain disruptions.

Contributing Factors

Several factors are driving the current availability challenges:

• Single-source manufacturing: Baloxavir Marboxil has no generic equivalent and is produced solely by Genentech. This creates a single point of failure in the supply chain that is particularly vulnerable during demand surges.
• Demand growth: Provider and patient adoption of Xofluza has increased year-over-year, driven by its single-dose convenience and expanded indications (now including post-exposure prophylaxis in patients ≥5 years and treatment in patients ≥5 years).
• Seasonal demand unpredictability: Influenza season severity and timing are inherently unpredictable, making pharmacy-level inventory forecasting difficult for a seasonal medication.
• Insurance and formulary barriers: Some payers require prior authorization or step therapy with Oseltamivir before approving Xofluza coverage. These delays can lead to patients arriving at pharmacies after inventory has been depleted, compounding apparent shortages.

For patient-facing information on these factors, see why Baloxavir Marboxil is hard to find in 2026.

Clinical Implications

The 48-hour treatment window for influenza antivirals makes medication availability a time-critical clinical concern. When Baloxavir Marboxil is unavailable, delays in filling prescriptions can push patients beyond the optimal treatment window, potentially diminishing therapeutic benefit.

Providers should be aware that:

• Patients may present with prescriptions they were unable to fill at their preferred pharmacy.
• The suspension formulation may have different availability than the tablet formulation.
• Post-exposure prophylaxis prescriptions may face additional insurance hurdles that compound availability issues.

Prescribing Strategies During Shortage

To mitigate the impact of Xofluza shortages on patient care, consider the following strategies:

1. Verify availability before prescribing. Direct patients to tools like MedFinder for Providers to check pharmacy-level availability in real time. The Xofluza product finder at xofluza.com can also provide availability data by zip code.
2. Prescribe alternatives proactively. When Xofluza availability is uncertain, consider providing patients with a backup prescription for Oseltamivir. This reduces the likelihood of patients exceeding the 48-hour treatment window.
3. Consider dual prescriptions. Write a primary prescription for Baloxavir Marboxil and a secondary prescription for Oseltamivir with instructions to fill whichever is available first. Ensure patient understanding of why two prescriptions are being provided.
4. Leverage telehealth e-prescribing. Telehealth platforms can route prescriptions to pharmacies with confirmed stock, reducing fill failures.
5. Communicate with pharmacy partners. Establish communication channels with preferred pharmacies to get ahead of stock-outs and direct patients accordingly.

Alternative Antiviral Options

When Baloxavir Marboxil is unavailable, the following FDA-approved influenza antivirals remain appropriate alternatives:

• Oseltamivir (Tamiflu/generic): 75 mg PO BID × 5 days. Widely available as generic. Most commonly used alternative. Approved for treatment in patients ≥2 weeks and prophylaxis in patients ≥1 year.
• Zanamivir (Relenza): 10 mg (2 inhalations) BID × 5 days. Contraindicated in patients with underlying airway disease (asthma, COPD). Approved for treatment in patients ≥7 years.
• Peramivir (Rapivab): Single IV dose (600 mg for adults). Reserved for patients unable to take oral or inhaled medications. Approved for patients ≥6 months.

For patient-facing alternative information, see alternatives to Baloxavir Marboxil.

Insurance and Access Considerations

Providers should be aware of common payer-level barriers that may compound shortage-related access issues:

• Prior authorization: Many commercial and managed Medicaid plans require PA for Xofluza. Given the time-sensitivity of influenza treatment, consider submitting PAs proactively during flu season for high-risk patients, or prescribe Oseltamivir concurrently.
• Step therapy: Some plans mandate a trial of Oseltamivir before approving Xofluza. Document clinical rationale when Xofluza is specifically indicated (e.g., medication adherence concerns, patient preference for single-dose therapy).
• Patient cost: Cash price for Xofluza ranges from $200-$250. Genentech offers a coupon (pay as little as $35 for commercially insured patients) and a $50 cash-pay option at select pharmacies. Direct patients to savings resources at xofluza.com or our savings guide.

Resources for Providers

• MedFinder for Providers — Real-time pharmacy availability search
• How to help your patients find Baloxavir Marboxil in stock — Provider workflow guide
• How to help patients save money on Baloxavir Marboxil — Provider cost-assistance guide
• FDA Drug Shortage Database — accessdata.fda.gov/scripts/drugshortages/
• Genentech Access Solutions — 1-866-422-2377

Summary

Baloxavir Marboxil availability during the 2025-2026 flu season has been inconsistent, driven by seasonal demand surges and single-source manufacturing. While not a formal shortage, the practical impact on prescribing and patient care is significant. Providers should verify availability before prescribing, have alternative prescribing strategies ready, and direct patients to resources like MedFinder for real-time availability information. Proactive communication with pharmacy partners and awareness of insurance barriers will help ensure patients receive timely influenza treatment.