Has anyone else ever experienced long lasting pain and or feeling in your cerebellum from too much use of LSD-25? I personally feel this is the only negative physical side effect I have ever had myself from LSD-25.
Have you experienced this with other psychedelics? It would also be important to determine where the pain is originating from. Is the pain always in the same place? Many headaches are caused by tension in the muscles of your head and neck. If massaging the area and loosening any cramps out helps, then LSD might just be changing your stance which uses stabilizer muscles in ways you're not used to, causing the soreness. Water (plus electrolytes) also usually helps to alleviate these types of headaches.
On the other hand, it could be receptor-mediated, possibly due to 5-HT1B and 5-HT1D downregulation? How soon does the pain start? If it's after your comedown this would make some sense. Lysergamides are also natural vasoconstrictors, so the pain is probably due to vasodilation, similar to a migraine or cluster headache. There are quite a few possible solutions worth trying. Many have suggested that caffeine is good a vasoconstrictor, and in this thread it was suggested that an oxygen tank might help. An in-depth description is provided by Batch on this cluster headache forum.