Yes, mar73, Botox if very effective for horizontal dynamic (caused by muscle movement) wrinkles on the forehead caused by the frontalis muscle. When injecting this muscle, though, it is important not to inject too much above the sides of the eyebrows, as this can cause the brows to droop or cause a "frozen", expressionless look to the face. I usually do not recommend filler to these horizontal lines, as these wrinkles tend to be too superficial for fillers to be effective. For excessive brow droop (or ptosis), you may eventually want to consider a surgical browlift procedure, either traditional open approach or an endoscopic approach for a more-permanent correction.
