UPDATE 1-Allergan gets subpoena on Botox promotion

(Adds details on company policy, background)

NEW YORK, March 3 (Reuters) - Allergan Inc (AGN.N) said on Monday that it received a subpoena from the U.S. Department of Justice investigating the promotion of Botox, a drug best known for its cosmetic use.

The drug maker said authorities were seeking documents regarding promotional, educational and other activities relating to Botox.

Allergan said it believes the subpoena is related to alleged off-label promotion of Botox to treat headaches.

Botox, which is best known for smoothing facial wrinkles, is not approved as a headache treatment.

Although Allergan is conducting trials to investigate the use of the drug to treat headaches, the company said that its policy is to comply with all applicable laws, rules and regulations in promoting its products.

But it noted that doctors are free to prescribe the drug for uses not approved by the U.S. Food and Drug Administration.

Allergan, which in November projected that worldwide sales of Botox would top $1.1 billion in 2007, said it is fully cooperating with the investigation.

The subpoena comes a few weeks after U.S. regulators said they were reviewing the safety of Botox and a competitor amid reports that at least one child died following treatment for serious medical conditions.

Botox has been approved to treat a variety of conditions including cervical dystonia, or rigid neck muscles. (Reporting by Chris Reiter, editing by Jacqueline Wong)