Patients are worried that porcine insulin will no longer be available this year, after a major firm has withdrawn their line, research shows.
Novo Nordisk withdrew their pork insulins this December but companies such as Wockhardt UK are still committed to creating the medicine line.
Ainslie Lang, diabetes specialist nurse at Royal United Hospital in Bath, said: "Insulin management plays such a huge part in a diabetic's life and for many, the prospect of moving away from a product that has worked for many years can be scary.
"There is certainly a group of patients that we know would be lost without porcine insulin and we are grateful that the choice remains available to them."
Sirjiwan Singh, managing director of Wockhardt UK, said: "We firmly believe that patient's freedom of choice should be maintained."
The Department of Health has stated that it fully accepts some people are better suited to porcine or bovine insulin and that these insulins will continue to be available.