What can help my paralyzed and drooping right eyebrow?

You will get no change in your brow position or nerve damage from Marijuana. If the brow position is severely asymmetric, it is unlikely that botox will significantly improve your condition either. Photos would be helpful to determine the extent of the asymmetry and whether a surgical approach might be beneficial for you.
 

Marijuana will not improve your brow symmetry or function of the muscle in any way. If your injury is more than 1-2 years old, it is unlikely that your brow function will spontaneously improve. If your injury is, 6 months old for example, you might see improved movement with time. Assuming this is an old injury there are two options. Botox can be used to subtly raise the weak side and decrease movement on the strong side to improve symmetry. This lasts about 3 months and will cause some improvement. The best option is typically a browlift surgery to lift the weak brow and improve symmetry. This is a safe procedure in experienced hands and will provide a permanent result. I hope this information is helpful.Stephen Weber MD, FACS