La Marca del Hombre Lobo on AllMovie

Distraught werewolf Waldemar Daninski (played by Spain's most popular horror movie star Paul Naschy) becomes so desperate to find a cure for his lunar-influenced affliction that he visits occult shopkeepers to find a cure. Unfortunately, those who seem anxious to help him turn out to be ruthless bloodsuckers. Originally filmed in 3-D, this film was a major hit in Spain. Before getting US released it had 45 minutes hacked away and was transferred to regular two-dimensional films. Naschy, using his birth name Jacinto Molina, wrote the script.