(NEW YORK) -- The U.S. Food and Drug Administration has issued a new warning about a popular medication used for weight loss.
The FDA says it has received reports of people overdosing on compounded semaglutide, giving themselves as much as 20 times more than the intended dose of the medication.
The incidents, some of which required hospitalization, involve semaglutide that is drawn from a vial and taken by injection, according to the FDA.
The agency said the dosing errors are a result of both patients measuring and self-administering incorrect doses of the medication, as well as health care providers "miscalculating" doses of the medication.
"Many of the patients who received vials of compounded semaglutide lacked experience with self-injections, according to the adverse event reports," the FDA said in a July 26 statement. "Unfamiliarity with withdrawing medication from a vial into a syringe and coupled with confusion between different units of measurement (e.g., milliliters, milligrams and "units") may have contributed to dosing errors."
The agency said patients should consult with a medical professional on how to measure and administer the correct dose, and that health care providers should "provide patients with the appropriate syringe size for the intended dose and counsel patients on how to measure the intended dose using the syringe."
Semaglutide is the active ingredient in three FDA-approved medications, Wegovy, Ozempic and Rybelsus.
While the FDA-approved medications are administered via either an oral tablet or pre-filled pens, compounded versions of semaglutide have patients draw the dose themselves from vials, which can lead to dosing errors.
Overdose symptoms of compounded semaglutide include nausea, vomiting, abdominal pain, fainting, headache, migraine, dehydration, acute pancreatitis and gallstones, according to the FDA.
People should contact their health care provider if they feel any symptoms.
The FDA is also encouraging people to report "adverse events" and "medication errors" to the agency via its online portal or by downloading and faxing an adverse event report.
The FDA has previously warned against the use of compounded semaglutide, citing safety concerns.
Compound pharmacies create their own semaglutide or tirzepatide compounds using raw ingredients. They are not the same as generic drugs, which are FDA-approved and monitored for safety and effectiveness.
There are currently no generic versions of semaglutide medications, including Ozempic and Wegovy.
"Patients should not use a compounded drug if an approved drug is available to treat a patient. Patients and health care professionals should understand that the agency does not review compounded versions of these drugs for safety, effectiveness, or quality," the FDA said in a safety warning earlier this year.
The warning came as many people reported turning to compounding pharmacies to get cheaper doses of semaglutide.
Without insurance coverage, the cost of medications like Ozempic, Rybelsus and Wegovy can run more than $1,000 a month.
Both Ozempic and Rybelsus are approved by the FDA to treat Type 2 diabetes, but some doctors prescribe the medication "off-label" for weight loss, as is permissible by the FDA.
Wegovy is FDA-approved for weight loss for people with obesity or who are overweight with a comorbidity like high blood pressure.