Biopharmaceutical companies are facing increased challenges in securing fetal bovine serum (FBS), a key input used to cultivate and sustain cells for research and manufacturing. The availability of FBS has become more limited, with release timelines now stretching from weeks to months.
FBS is derived from bovine fetuses and provides essential growth factors and proteins needed for most cell lines. While some drug development programs have considered substitutes, these alternatives require extensive validation and can behave differently in culture, making FBS difficult to replace once a project is underway.
The supply situation is particularly strained in the United States. The domestic cattle population reached its lowest July inventory on record in 2025, with only 94.2 million head reported by the USDA as of July 1, 2025. This decline restricts the raw material available for producing FBS. Additionally, disease outbreaks in Europe have further tightened global supply. For example, France confirmed a case of lumpy skin disease in June 2025, leading to herd culls and export restrictions on cattle and related products.
U.S. regulations also impact imports: the USDA prohibits importing bovine products from regions experiencing disease outbreaks. As a result, buyers have redirected orders to countries still eligible under animal-health import rules, increasing demand for U.S.-approved supplies and tightening markets further.
Demand for FBS continues to rise due to expanding pipelines for cell, gene, and RNA therapies. Many biologics developers prefer to keep using FBS throughout multi-site studies to ensure comparability with earlier data. Once a program reaches Phase II clinical trials, manufacturing processes—often including FBS—are locked in place for regulatory consistency.
Regulatory requirements add additional delays; imported FBS must undergo safety testing at the National Veterinary Services Laboratories (NVSL). The Animal and Plant Health Inspection Service (APHIS) has warned stakeholders about backlogs that were exacerbated during the recent government shutdown when staffing at NVSL was reduced. Even after operations resumed, purchase-to-release gaps remain measured in months rather than weeks.
These combined factors have driven up prices sharply; industry reports show that U.S. FBS prices have risen more than 300% over five years. Analysts estimate that the global market for FBS was valued at about $1 billion in 2025 and could reach $1.3 billion by 2029 as biopharma demand grows while raw material supply remains tight.
Additional uncertainty arose in 2025 when the United States introduced “reciprocal” tariffs on certain imports—a measure currently under quarterly review but not yet enacted—which prompted companies to budget for possible higher costs even before any duties are applied.
As serum prices increase due to these pressures, so do therapy production costs per batch. Delays in APHIS release add carrying costs as inventory sits idle awaiting clearance. When shipments stall or new lots take months to clear testing, some teams resort to spot purchases outside contracted allocations—often paying premium rates—or stockpiling serum ahead of time at significant cost.
None of these developments support policy goals aimed at lowering drug prices.
Industry experts suggest several strategies to help companies manage high FBS costs:
“Companies should keep specs flexible,” said an executive director and co-founder of SeraPrime who works globally with manufacturers and biopharma teams supplying FBS and other reagents.“Where science and regulation allow, define acceptance criteria by safety testing and performance of FBS batches, not a single country of origin... standardize protocols before Phase II.”
Drug developers are also encouraged to diversify their supply sources by working with multiple origins or suppliers instead of relying on last-minute spot buys; planning longer lead times; sizing inventories appropriately; aligning budgets with current freight realities; and educating procurement staff about treating constrained reagents like FBS differently from standard materials.
“Proactive governance, flexible specifications, redundant qualification and realistic clocks reduce risk more reliably than any single substitution,” the SeraPrime executive added.“In my opinion, that’s how teams keep science moving while protecting downstream value for patients.”
