I find drinking cayenne pepper tea (a teaspoon of cayenne pepper in hot water) helps to relieve hypnic jerks. Info on Cayenne pepper and all its benefits is just a google search away but it helps regulate blood pressure and is awesome for heart health. I had hypnic jerks last night for the first time in months and tried cayenne pepper tea (which you can also have with green tea and a dash of cinnamon or lemon etc - see many online recipes) - and I was DELIGHTED to see it eased my hypnic jerking when drifting off to sleep almost immediately after getting back to bed and tying to fall asleep!