Since Novalgin (metamizole) is banned in many regions due to safety risks, safer alternatives are available for severe headaches. For over-the-counter relief, you can try Ibuprofen (400 mg) or Paracetamol (Acetaminophen, 500-1000 mg). Combination pain relievers containing caffeine can also be highly effective. If you suffer from severe, migraine-like headaches, prescription medications called Triptans (such as Sumatriptan) are the gold standard. I highly recommend consulting a doctor to determine the exact cause of your severe headaches and to get a safe, personalised prescription.