Complaints included consumers who have been trying to find EpiPens in Seattle since March to no avail, patients who said their EpiPen had expired and they are currently without one, patients who were repeatedly told the drug is on “back-order,” and one who reported trying 10 pharmacies before finding an EpiPen.

Linnea Clary, who lives in York, Me., said her son’s EpiPens expired in February and she had been unable to refill the prescription, despite trying different pharmacies, including one at a large hospital in Boston. “I can’t fill it, period,” she said.

Mylan is encouraging consumers who are unable to fill an EpiPen prescription to call its customer service line at 800-796-9526 between 8 a.m. and 5 p.m. Eastern Time for assistance in locating a pharmacy that has the product in stock.

FARE has called on the F.D.A. and the Department of Health and Human Services to notify both the general public and health care providers of the shortages, and to inform insurers they may need to cover alternative medications.

The organization is urging the F.D.A. to take steps to alleviate the shortage, either by expediting reviews of new generic epinephrine auto-injectors or importing other products.

“This is a life and death issue for people with systemic allergic reactions,” said Dr. James Baker, FARE’s chief executive and chief medical officer. “If you have one of these attacks, the only thing you can do to keep yourself from going into shock is to give yourself the epinephrine and then get to the emergency room. And if you don’t have it, you may not make it to the emergency room.”

The shortage is not unique: dozens of drugs are on the F.D.A.’s list of medication shortages, including injectable anesthesia agents, pain medications, penicillin, feeding and hydration solutions, heart disease drugs, and even simple products like sterile water.