New Hampshire residents buying medicine online should verify the seller's license and prescription requirements, the attorney general's office warned Oct. 20.

The consumer alert says illegal sellers can supply counterfeit medicine containing the wrong ingredients, contaminants or unexpected drugs such as fentanyl. A professional-looking website does not establish that a seller is licensed or that its products are authentic.

The office recommends checking the mail-order and nonresident pharmacy registry maintained by the New Hampshire Office of Professional Licensure and Certification and using the Food and Drug Administration's BeSafeRx resources. The National Association of Boards of Pharmacy also provides a Safe Site Search tool.

A legitimate online pharmacy should require a valid prescription when one is needed and provide access to a licensed pharmacist, according to the alert. The alert advises using only pharmacies that require both.

Suspected illegal sellers can be reported through the FDA or the New Hampshire Department of Justice's consumer-protection complaint process.

Sources: CONSUMER ALERT: Granite Staters Warned About Dangers of Counterfeit Medicines and Illegal Online Pharmacies.