Hemp is a food product derived from the same plant of which Marijuana originates from, but without intoxicating components; the protein fragment appears to be a popular meal replacement supplement but is not yet linked to unique properties (relative to other Protein supplements).
Hemp Protein is most often used for
Hemp protein is a industrial byproduct from hempseed where the seeds (balanced macronutrient profile) have their oil extracted into Hempseed oil, and the remainding seedmeal that is high in protein relative to the seeds is then processed into Hemp protein supplements.
Hemp that is currently on the market is a strain low in THC (the intoxicant and psychoactive agent in Marijuana) and does not confer intoxicating properties. It is usually not a pure protein supplement, as it has up to 10% fatty acids by weight (pretty balanced between omega-3 and omega-6 fatty acids and generally high in polyunsaturated fatty acids) and confers a higher inherent fiber content relative to other Protein supplements. The protein portion of hemp is not a complete protein source, due to being low in Lysine (the rate limiting essential amino acid); it is also relatively low in leucine, but is relatively high in both L-Tyrosine and Arginine.
There is a cannabinoid content in Hemp, although they are cannabinoids that do not interact with the two classical cannabinoid receptors in the human body and are unlikely to have the same neural properties attributed to marijuana. These may confer some health properties unique to hemp products (either hempseed protein or Marijuana) but in the context of using hemp protein as a meal replacement they are not studied.
Currently, hemp protein appears to be a viable meal replacement option and has the benefit of having a higher fiber content but is not yet linked to unique health benefits (or harms) to establish its importance over other dietary sources of protein.
Like any protein supplement, hemp protein supplements are dosed in relation to dietary protein goals and how much dietary protein is consumed via other sources. Protein goals vary from person to person, but a general guide is:
If you are an athlete or highly active person currently attempting to lose body fat while preserving lean muscle mass, a daily intake of 1.5-2.2g/kg bodyweight (0.68-1g/lb bodyweight) would be a good target
If you are an athlete or highly active person, or you are attempting to lose body fat while preserving lean mass, then a daily intake of 1.0-1.5g/kg bodyweight (0.45-0.68g/lb bodyweight) would be a good target
If you are sedentary and not looking to change body composition, a daily target of 0.8g/kg bodyweight (0.36g/lb bodyweight) and upwards would be a good target
Supplementation of hemp protein should be in the dose that is required to meet these ranges after dietary protein has been accounted for. If dietary protein has adequately reached these ranges, then protein supplementation is not required.
Obese individuals (body fat over 20/30% for males and females or a BMI greater than 30 without significant levels of muscle mass) should not follow the above recommendations exactly as the state of obesity would overshoot requirements. In these instances, calculate your targets based upon what your weight would be assuming an overweight BMI.
Eating a high-protein diet doesn't appear to harm the kidneys or liver unless there is pre-existing damage and dysfunction. It's possible that dramatically increasing protein intake in a short timespan can lead to adverse effects on the liver and kidneys, but evidence for this is lacking. Bone health also appears to be either largely unaffected or benefited by eating more protein.
Several scales have been developed to rate proteins according to their respective bioavailabilities and, more recently, amino acid profiles. Those scales can help guide your choice of protein, as long as you understand their premises and limitations.