Why Supplier Diversification Doesn't Ensure Supply Safety

By Shammi Thakur

Qualifying a second supplier can make a pharmaceutical supply plan look safer without changing where its most consequential dependencies sit. A procurement system may show two or three approved vendors, while an interruption farther upstream can still affect them all.

A July 2026, semaglutide disruption demonstrated how an issue involving an API can travel beyond the company that first encounters it. Dr. Reddy’s Laboratories disclosed that an impurity issue associated with semaglutide API had affected production, while reporting on the event identified downstream implications for Torrent Pharmaceuticals, which used Dr. Reddy’s API in its semaglutide products.

Events like that make supplier count an incomplete measure of resilience. The more useful question is whether separate supply arrangements remain independent when a critical material, capability, or route fails.

Tier-One Visibility Can Create False Confidence

Most supplier-management systems are built to answer a practical purchasing question: who is approved to supply the material? That answer becomes less useful when the same supplier base shares something it does not show.

A manufacturer might have:

• Three qualified API suppliers using the same critical intermediate producer,
• Multiple finished-dose sources dependent on one specialist excipient,
• Separate manufacturing sites using the same constrained testing capability, or
• Different suppliers routing critical materials through one logistics gateway.

Each arrangement looks diversified from the first tier. None necessarily provides three independent paths to production.

That distinction matters as the United States pushes to rebuild domestic pharmaceutical capacity. The U.S. Food and Drug Administration (FDA) has said more than half of pharmaceuticals distributed in the country are manufactured overseas. Its October 2025 announcement on generic-drug manufacturing reported that only 9% of API manufacturers were located in the United States, compared with 22% in China and 44% in India.³

Analysis of the U.S. API market also breaks the supply base down by manufacturer type, including captive and merchant production, and by end user, including pharmaceutical manufacturers and contract development and manufacturing organizations (CDMOs). That structure matters because concentration can emerge at different points in the API ecosystem, not simply at the level of a manufacturer’s direct supplier.

The figures support greater domestic manufacturing. They do not, by themselves, establish an independent supply network. Moving API or finished-dose production closer to the end market can remove one dependency while leaving another untouched upstream. The resilience question therefore has to move beyond facility location and approved-vendor count.

The Dependency Often Sits One Step Further Back

Useful reviews start with the material that could interrupt production, then work backward until every major dependency is visible. Following one critical product through its chain provides a practical starting point:

Starting material → intermediate → API → formulation → manufacturing → packaging → testing → release → distribution

At each stage, look for convergence.

• Shared upstream sources can turn several approved suppliers into one exposure.
• Shared physical routes can reconnect otherwise separate supply chains through the same port, transport corridor, industrial zone, or energy network.
• Scarce technical capabilities can become the bottleneck even when materials are available. Specialist synthesis, analytical testing, sterile processing, equipment, or other services may have limited substitutes.
• Long qualification paths can make an apparently available supplier unusable when a disruption is already underway.

Qualification time deserves particular attention in pharmaceutical manufacturing. An alternative source does not become a real alternative simply because it exists commercially. It must be qualified to produce material that can enter the regulated process within the timeframe required to protect supply.

Conventional supplier-diversification exercises can therefore stop too early.

Reshoring Does Not Remove Every Dependency

Domestic manufacturing is now receiving substantial policy and capital support.

FDA launched its PreCheck Pilot Program in February 2026 to facilitate development of new U.S. pharmaceutical manufacturing facilities through earlier regulatory engagement. On June 29, the agency selected seven participants from more than 80 requests, including projects involving APIs, sterile products, cell and gene therapies, and biomanufacturing.

The investment matters. So does the question of what sits behind each new facility. Domestic plants can still depend on:

• Imported starting materials or intermediates,
• Specialty chemicals and excipients,
• Foreign equipment or components,
• External analytical and testing capabilities, and
• Transportation infrastructure exposed to international disruption.

FDA's own PreCheck criteria reinforce the importance of upstream sourcing: the agency says priority may be given to facilities that use domestically sourced key starting materials

This guidance changes how localization should be assessed. The relevant question is not simply whether a manufacturing step moves to the United States. It is whether the move removes a critical dependency or only relocates one part of a longer chain.

Recent investments show why the distinction is timely. Eli Lilly announced a $3.5 billion Pennsylvania manufacturing site in February 2026, while Bristol Myers Squibb announced a $2.3 billion manufacturing campus in Houston in August. Those projects add significant U.S. capacity, but capacity additions should still be evaluated against their upstream material and infrastructure dependencies.

More facilities can strengthen resilience. More facilities with the same hidden dependencies may not.

An Alternate Source Still Has to Be Usable

Once dependencies are mapped, the next question is whether proposed alternatives can actually protect production. A practical assessment can move through five decisions.

1. Start with the consequence: Which failure would create the greatest impact on production, release, or patient availability? A critical API precursor deserves a different level of contingency planning from an input that can be replaced without technical or regulatory delay.
2. Trace the alternate source upstream: An alternate supplier needs the same scrutiny as the incumbent. A second vendor that purchases the same constrained precursor has not solved the underlying exposure.
3. Put qualification on the clock: Estimate the actual time required for audits, analytical testing, process changes, technology transfer, validation, stability work, and regulatory activities. A source that cannot be activated before available inventory is exhausted is not an effective short-term backup.
4. Stress-test capacity: Ask how much volume the alternate source could absorb if several customers were affected simultaneously. Nominal capacity and usable surge capacity are not interchangeable.
5. Choose mitigation according to the failure: Different vulnerabilities require different forms of protection, so the response should address the dependency most likely to interrupt qualified production. Single-source materials may require alternate qualification, long qualification cycles may justify advance technical work, while geographic or logistics concentration may call for genuinely separate routes or additional contingency capacity.

The purpose is not to maximize the number of suppliers. It is to create enough independent options at the points where failure could stop production.

Measure The Time Between Failure and Recovery

“Dual sourced” is useful procurement information, but it says little about what happens once the primary route is disrupted. A resilience assessment becomes more meaningful when it measures the time available to absorb a failure and the time required to restore qualified supply.

Several measures can expose that gap:

• Supplier concentration: How much production depends on one direct source?
• Upstream concentration: How many approved suppliers ultimately depend on the same critical input or capability?
• Qualification time: How long would an alternate source take to become commercially usable?
• Capacity headroom: Could an alternate source absorb transferred demand without creating another bottleneck?
• Inventory coverage: How much time does available stock provide while another route is being activated?
• Recovery time: How long could production remain exposed after a critical dependency fails?

FDA's calendar year 2025 drug-shortage report provides a useful example of why early intervention matters. The agency recorded four new drug shortages during 2025, the lowest annual number in a decade, while FDA and manufacturers reported preventing 330 potential shortages through intervention and mitigation measures.

Predictive visibility is becoming part of that approach. The U.S. Government Accountability Office reported that FDA had implemented a system providing drug-shortage staff with monthly predictions of supply disruptions that could contribute to shortages.

Manufacturers can apply the same principle to their own networks. A useful resilience review should connect critical dependency → likely failure impact → alternative source → qualification time → available capacity → recovery window rather than stopping at a supplier-status field.

Resilience Starts Where Supplier Lists End

Supplier diversification remains an important part of pharmaceutical supply planning. Problems emerge when diversification is judged only by the number of approved vendors or manufacturing sites. Upstream dependencies can leave several suppliers exposed to one material, capability, or infrastructure constraint. Domestic facilities can still rely on imported inputs. Alternate sources can exist commercially without becoming usable quickly enough to protect production.

Resilience ultimately depends on what remains available after a critical dependency fails. Manufacturers should therefore measure diversification by the number of qualified, genuinely independent paths that can sustain supply through disruption—not simply by the number of suppliers on the list.

Author Bio:

Shammi Thakur is Research Director at MarkNtel Advisors, with more than 15 years of experience in strategic market intelligence, industry forecasting, and competitive analysis. He leads research across pharmaceutical and healthcare markets, focusing on industry trends, supply-chain developments, market dynamics, and evidence-based insights for business and industry decision-makers.