NHS Medicine Supply Chain Explained

The Journey of a Medicine

Every prescription medication you collect from the pharmacy has been on a remarkable journey. Here's how it works, step by step:

Step 1: Active Ingredient Manufacturing

Most medicines begin life in a chemical or biological manufacturing plant, often in China or India. These facilities produce the Active Pharmaceutical Ingredient (API) — the chemical compound that gives a medicine its therapeutic effect. Around 60-80% of global API production occurs in China and India, creating a geographical concentration that can be a vulnerability.

API manufacturing is a precision process requiring strict quality control. Each batch must be tested for purity, potency, and contaminants. Manufacturing a single API can take weeks to months.

Step 2: Formulation and Finishing

The API is then shipped to a pharmaceutical manufacturer (which may be in a different country) where it's formulated into the final product — tablets, capsules, liquids, patches, injections, etc. This is called "secondary manufacturing" or "fill and finish."

Many of the branded and generic medicines used in the UK are formulated in facilities across Europe, India, and the UK itself. This stage adds excipients (inactive ingredients), applies coatings, and packages the medicine for sale.

Step 3: Quality Testing and Batch Release

Before any batch of medicine can be sold, it must be tested by a Qualified Person (QP) — a specially licensed individual who certifies that the batch meets all quality specifications. In the UK, the MHRA oversees this process. Batch release can take days to weeks depending on the complexity of testing required.

Step 4: Import and Distribution

Medicines entering the UK must pass through customs and meet import licensing requirements. They're typically delivered to the warehouses of pharmaceutical wholesalers — the intermediaries between manufacturers and pharmacies.

The UK has three major pharmaceutical wholesalers:

• Alliance Healthcare (now part of Cencora) — supplies many independent pharmacies and some chains
• AAH Pharmaceuticals (part of McKesson) — the UK's largest wholesaler
• Phoenix Healthcare Distribution — supplies Rowlands and other pharmacies

These wholesalers operate huge distribution centres across the UK, each holding thousands of product lines. They deliver to pharmacies daily, often overnight.

Step 5: Pharmacy Dispensing

When you present a prescription, your pharmacist orders the required medicine from their wholesaler (or may have it in stock). Most community pharmacies hold limited stock and rely on daily deliveries. Larger pharmacies and hospitals maintain bigger inventories.

Where Things Go Wrong

At each stage of this chain, there are potential failure points:

Manufacturing Disruptions

Factory shutdowns (for maintenance, quality issues, or regulatory action), natural disasters, and geopolitical events can all interrupt API supply. When a key API factory shuts down, it can take months to restart production and rebuild stock.

Quality Failures

If a batch fails quality testing, the entire batch must be discarded. For medicines with limited suppliers, a single batch failure can cause weeks of shortage. The MHRA regularly issues recalls and alerts for quality issues.

Commercial Decisions

Manufacturers sometimes discontinue products that aren't commercially viable. The UK's drug pricing system (the Voluntary Scheme for Branded Medicines Pricing and Access, or VPAS) can make some medicines less profitable to supply to the UK market than to other countries.

This is a growing concern: if the UK pays less than other markets, manufacturers may prioritise supply to higher-paying countries during shortages.

Logistics and Transport

Brexit introduced new customs requirements for medicines entering the UK from the EU. While mitigations have been put in place, the additional bureaucracy adds time and cost to the supply chain. Read more about Brexit's impact on medicine supply →

Demand Spikes

Sudden increases in demand — whether from seasonal illness, media coverage, or pandemic stockpiling — can overwhelm a supply chain designed for steady-state operations. The COVID-19 pandemic demonstrated how quickly pharmacy shelves can be stripped when patients rush to stockpile.

The Role of the DHSC

The Department of Health and Social Care plays a central role in managing medicine supply:

• Medicine Supply Team: A dedicated team that monitors supply and intervenes when shortages threaten
• Serious Shortage Protocols (SSPs): Legal instruments that allow pharmacists to supply alternative products without a new prescription
• Strategic Stockpile: The UK maintains reserves of essential medicines for emergencies
• Manufacturer engagement: DHSC works with companies to resolve supply issues and prevent shortages
• Data collection: Manufacturers must notify DHSC of anticipated supply disruptions

Learn more about how the DHSC manages supply →

How MedWatch Fits In

MedWatch monitors official DHSC medicine supply notifications, SSPs, and other data sources to track shortages in real time. When a shortage is identified, we alert affected patients so they can take action before running out of medication.

Read about how our tracker works →

Further Reading