Mounjaro's First Year in Brazil: From Launch to R$13.5 Billion in Sales

When Eli Lilly launched its weight-loss pen Mounjaro in Brazil in May 2025, the company expected a strong debut in a market already primed by Novo Nordisk’s Ozempic and Wegovy. What happened next outpaced even Lilly’s internal forecasts. Within twelve months, the drug, based on the original molecule tirzepatide, racked up R$13.54 billion in sales and reached nearly 3 million patients, according to the company.

The demand surge forced Lilly to scramble. Some dosages became intermittently unavailable as the company raced to rebalance its supply chain, eventually running factories 24/7 to secure additional volumes for Brazil. Today, all presentations from 2.5 mg to 15 mg are back on pharmacy shelves, and the Brazilian subsidiary has leaped into the top 10 of Lilly’s global affiliates, with the explicit aim of breaking into the top five within a few years.

The Brazilian operation more than tripled its revenue in 2025 compared to 2024 and expects to more than double it again in 2026. Globally, Lilly reported a 56% jump in first-quarter 2026 revenue to US$19.8 billion, with incretin-based therapies like Mounjaro as the primary engine. Felipe Berigo, executive director of cardiometabolism at Lilly, told EXAME that the initial uptake “went far beyond expectations” and that “the unmet medical need was even greater than we imagined.”

Inside Eli Lilly's Brazilian Surge and the Looming Generic Wave

Mounjaro’s explosive launch is not just a company-level win; it is a snapshot of a Brazilian obesity and diabetes market in rapid transformation. According to Nielsen, GLP-1 receptor agonist pens are already present in 4.6% of Brazilian households, and the sector’s total value is climbing steeply.

Where Lilly’s Brazilian Gamble Paid Off

Tirzepatide’s dual action on GIP and GLP-1 receptors gave Lilly a scientific differentiation from the start, but the sheer volume of demand suggests that years of limited therapeutic options had created a deep backlog of patients ready to switch to more effective treatments. Berigo stressed that the molecule’s mechanism, not an absence of competition, is what sustains the company’s leadership position. However, the sales trajectory also reflects a deliberate corporate strategy to transform Brazil from a peripheral market into a pillar of global growth. Lilly’s local investments in clinical research—59 ongoing studies, 8,000 active patients and over 300 research centers—underscore that ambition.

The Semaglutide Patent Cliff Arrives

The competitive landscape has already shifted dramatically. In March 2026, the patent on semaglutide expired in Brazil, opening the door to generic and similar versions. Since then, at least seven new injectable semaglutide-based medications have been approved by health regulator Anvisa. BTG Pactual analyst Luiz Guanais estimates that this wave of generics could add R$3.6 billion to the market in 2026 alone, pushing the total to R$15.6 billion. While tirzepatide is clinically more effective, Guanais notes that Lilly now faces pressure to reduce prices because less effective but far cheaper alternatives are flooding the market.

The Parallel Market and Quality Risks

Alongside the formal market growth, a dangerous parallel circuit is also expanding. In a recent Federal Police and Anvisa operation, 3.5 kilograms of tirzepatide were seized from compounding pharmacies across 12 states—enough to produce more than 1 million injection pens. Investigators also found experimental substances without regulatory approval. Berigo warned that the real concern is public health: “We have knowledge of samples with contamination, impurities and even substances completely different from what they claim. This is a public health problem that worries us much more than any market dispute.” Lilly’s response is to reinforce the legal, regulated supply chain rather than engage in a price war, betting that safety and proven efficacy will continue to differentiate its brand.

What the Mounjaro Milestone Means for Pharma Executives and Investors

For executives at pharma companies with GLP-1 portfolios and for investors following the obesity treatment boom, Mounjaro’s first year offers several concrete indicators.

  • For Eli Lilly: The supply crisis in mid-2025 demonstrated that rapid demand can outstrip even 24/7 factory operations. Continued investment in global manufacturing capacity—which has already exceeded US$50 billion since 2020—must be matched by accurate local allocation models, especially as the Brazilian affiliate targets a top-five global ranking. The company’s plan to more than double revenue locally in 2026 will require maintaining availability of all doses.
  • For competitors (Novo Nordisk and generic entrants): The expiration of semaglutide’s patent creates an immediate, high-volume opportunity in Brazil. Generic manufacturers can capture price-sensitive segments, but they must scale quickly and compete on distribution reliability, not just price. Novo Nordisk, meanwhile, is banking on its pipeline of next-generation molecules like CagriSema and IcoSema to defend its franchise—but that strategy will face its own timeline and regulatory hurdles.
  • For regulators and public health officials: The seizure of over one million doses’ worth of illicit tirzepatide underscores the urgency of strengthening oversight of compounding pharmacies. Any lapses that allow contaminated or mislabeled products to reach consumers could trigger a confidence crisis across the legitimate GLP-1 market.
  • For investors: The Brazilian unit’s leap into Lilly’s top 10 affiliates signals that emerging markets are becoming a material part of the incretin revenue story. Watch for Lilly’s quarterly disclosures on volume growth in international markets and any commentary on price erosion as semaglutide generics ramp up. The BTG estimate of R$3.6 billion in new generic sales by end-2026 provides a benchmark to gauge whether Lilly can maintain its share or whether the competitive mix is shifting faster than its pipeline can compensate.

Risk & Opportunity Assessment

Commercial RiskMediumDemand for Mounjaro remains robust, but the influx of cheaper semaglutide generics—expected to add R$3.6 billion to the market—could slow Lilly's volume growth or force margin-diluting price cuts.
Competitive RiskHighThe semaglutide patent expiration unleashed at least seven new injectable competitors in weeks. While tirzepatide is more effective, price-conscious patients and payers may switch to generics that are 'good enough,' intensifying market share erosion.
Regulatory RiskMediumAnvisa's aggressive approval of generics is enabling competition, but its crackdown on illegal compounding pharmacies could disrupt informal supply channels, indirectly affecting perceptions of the entire GLP-1 category if public health incidents occur.
Reputation RiskLowLilly's brand is not directly implicated in the parallel market scandals, but any high-profile safety incident involving counterfeit tirzepatide could cast doubt on the regulated market and heighten patient anxiety.
Technology DisruptionMediumNovo Nordisk's pipeline candidates (CagriSema, IcoSema) and other R&D-stage dual- or multi-agonists could leapfrog tirzepatide. Lilly's ongoing 59 clinical studies in Brazil are a defensive moat, but breakthrough rival molecules could undermine its dual-agonist advantage.
Commercial OpportunityHighThe nearly 3 million patients reached in year one, combined with a household penetration of only 4.6%, indicates a vast untapped market. Lilly's strategic push to make Brazil a top-five global affiliate opens the door to disproportionate revenue growth if it can sustain supply and defend its differentiation.