Hemp milk is made from the seeds of the edible part of the same plant (Cannabis sativa L) used to make marijuana. The seeds or "nuts" are used for making oil, protein powder and now, milk. The seeds, and products made from them, don't contain any THC delta-9-tetrahydrocannabinol), the psychoactive component of marijuana.
Hemp seeds have a rich, nutty flavor, something like sunflower seeds. I like them toasted with a bit of salt or garlic. Hemp milk is made by pulverizing the seeds, blending them with water and straining out the solid residue. The resulting "milk" provides both omega-6 and omega-3 essential fatty acids in a healthy three-to-one ratio. However, the omega-3 in hemp is alpha-linolenic acid, not the more desirable forms (EPA and DHA) found in fish oil. Other nutrients include magnesium, phytosterols, ascorbic acid, beta-carotene, calcium, fiber, iron, potassium, phosphorus, riboflavin, niacin and thiamin.
Hemp milk also contains 10 essential amino acids, making it a good vegetarian source of protein (although I've read that the quality of protein in hemp may not measure up to soy protein). However, according to the manufacturer of one brand of the milk, hemp protein does not contain phytates, enzyme inhibitors found in some soy protein that can interfere with the assimilation of essential minerals. The same manufacturer maintains that hemp protein is more digestible than soy protein because unlike soy, it contains no oligosaccharides, complex sugars that can cause flatulence if not properly broken down during digestion.
As far as allergies are concerned, hemp seeds and nuts do not pose the threat that tree nuts do. Similarly, anyone allergic to soy or dairy should be able to safely consume hemp milk.
Hemp milk is said to taste more creamy and nutty than soy milk or rice milk. And it tends to be a bit thicker than those other products, but you should still avoid any product that uses carrageenan as a thickening agent. Recently, I tried some delicious hemp ice cream, one of the best nondairy frozen desserts I've come across (Tempt from Living Harvest, www.livingharvest.com). Other foods made with hemp now on the market include cereals, waffles, and snack bars.
Overall, I think hemp milk is a good thing. Try it.
Andrew Weil, M.D.