A gonadotropin is administered within a surprisingly effective narrow range for the purpose of treating chronic pain or other central sensitization sequelae. In one aspect a recipient is provided with at least one of human chorionic gonadotropin (uHCG and /or rHCG) a pharmaceutically active HCG analogue and a pharmaceutically active metabolite of the HCG or analogue at a dosage selected to provide an amount therapeutically bioequivalent to a human subcutaneous dosage of between 120 IU/day and 170 IU/day of HCG and more preferably between 140 IU/day and 160 IU/day of HCG. A combination product is also described which includes a supply of the HCG related drug a delivery device and a conversion scale for therapeutic bioequivalence that identifies the specific amount and route of administration for chronic pain or central sensitization as an indication of the drug.
