Hemp smoothies and hemp-laced muffins could appear on shop shelves and cafe menus by the year's end following a decision to legalise the cannabis plant's seeds for human consumption.

After rejecting proposals to amend the Food Standards Code as far back as 2002, state and federal health ministers have now decided hemp - the same species as marijuana - is safe to eat.

"The standard will take effect six months after it has been gazetted and ministers acknowledged that there is still a range of New Zealand and State and Territory legislation that currently prohibits the sale of low-THC hemp seeds as a food which will need to be amended," reads a communique from health ministers at the Forum of Food Regulation on Friday.

Industrial hemp, unlike marijuana, has extremely low levels of the mind-altering chemical tetrahydrocannabinol (THC). But ministers had feared it would affect roadside drug testing and make them appear soft on drugs.