An image produced using optical microscopy shows Clostridium botulinum, an ingredient in Botox and similar cosmetic substances. The purified form of the botulinum toxin is approved by the FDA for use by licensed health-care providers as a cosmetic treatment.
CNN  — 

Nineteen people from nine states have reported harmful reactions after receiving cosmetic injections — commonly known as Botox — that were administered from unlicensed or untrained individuals or in non-medical settings, the US Centers for Disease Control and Prevention said Monday. Some people received injections of counterfeit or mishandled product.

Nine people were hospitalized and four were treated with botulism antitoxin because of concerns that the botulinum toxin could have spread beyond the injection site, the agency said.

The reactions to the products occurred in Colorado, Florida, Illinois, Kentucky, Nebraska, New Jersey, New York, Tennessee and Washington.

The CDC says all 19 people identify as female and range in age from 25 to 59 years old. All but one reported receiving the injection for cosmetic purposes.

The agency, along with several state and local health departments, and the US Food and Drug Administration are investigating the reports.

The CDC advises asking providers and settings, such as clinics or spas, if they are licensed and trained to give the injections. It also advises asking if the product is FDA approved and obtained from a reliable source. If in doubt, the agency advises not to get the injection.

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Botulism is a rare but serious illness caused by toxins released by bacteria that attack the nervous system. Symptoms can include blurry or double vision, droopy eyelids, difficulty breathing, fatigue, slurred speech or hoarse voice. Muscle paralysis may progress over hours to days if left untreated and can be fatal.

The Clostridium botulinum bacteria is an ingredient in Botox and similar cosmetic substances, according to the Illinois Department of Public Health. The purified form of the botulinum toxin is approved by the FDA for use by licensed health-care providers as a cosmetic treatment, it said in a news release published last week.

CNN’s Deidre McPhillips contributed to this story.