MCT Oil Versoin Vs Grape Oil Version Gears Personally I think some people are allergic to grapeseed oil based gears which is why we’ve now made a listing for a MCT oil basedversion. MCT oil may be a better choice even for someone who doesn’t suffer from grapeseed oil allergies, this is because MCT oil tends to be less viscous (thinner) than grapeseed oil meaning it’s easier to draw into a syringe and inject.