A doctor and his wife have been convicted of treating patients with a Botox knockoff at their Las Vegas clinic.

Federal jurors returned the verdict late Wednesday against 53-year-old Dr. Stephen Lee Seldon and 41-year-old Deborah Martinez Seldon. They are convicted of mail fraud and adulterating a drug while held for sale.

Deborah Seldon was her husband's office assistant at A New You cosmetic clinic. Prosecutors say patients thought they were getting Botox treatments to reduce facial wrinkles but got the cheaper TRItox instead.

The government says the substitute was research quality and not for human use. The Seldons could face decades in prison when they are sentenced in February.