Summary of Hemp Protein
Primary Information, Benefits, Effects, and Important Facts
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.
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Things To Know & Note
There is a low THC content in hemp protein and supplementing the protein will likely not confer any intoxicating properties
Hemp protein is known to not have the most desirable taste. It may be prudent to taste hemp first (via free samples or a friend) before making a purchasing decision
How to Take Hemp Protein
Recommended dosage, active amounts, other details
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.
Human Effect Matrix
The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects hemp protein has on your body, and how strong these effects are.
|Grade||Level of Evidence [show legend]|
|Robust research conducted with repeated double-blind clinical trials|
|Multiple studies where at least two are double-blind and placebo controlled|
|Single double-blind study or multiple cohort studies|
|Uncontrolled or observational studies only|
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
|-||Very High See 2 studies|
|-||Very High See 2 studies|
|-||Very High See 2 studies|
|Minor||- See study|
|-||- See study|
Scientific Research on Hemp Protein
Click on any below to expand the corresponding section. Click on to collapse it.
Hemp is the common name for the plant Cannabis sativa, which has a history of being a multipurpose crop for fiber, food, and medicinal products; farming of Hemp was banned around 1930 due to the psychoactives in Marijuana and was repermitted in 1998 (Canadian data but appears to extend to Australia, Austria, China, Great Britain, France and Spain but not the US  ) due to Hemp being bred to contain less than 0.3% of the main main marijuana psychoactive (delta-9-tetrahydrocannabinol).  All hemp products sold as food products (legally) abide by this and appear to contain less than 0.3% THC (in reference to total product weight).  
Hemp can be cultivated for the oil component or the fiber component with the latter being more popular economically, and has some roots in Traditional Chinese Medicine where the seed kernel is referred to as Huo Ma Ren  for the treatment of conspitation, gastrointestinal disease, and aging.  Hempseeds are also referred to as Fructus cannabis (fruits of cannabis). 
The seeds of Hemp tend to contain Around 2200kJ (525kcal) per 100g 30.4+/-2.7% and 24.0+/-2.1% fatty acids and proteins respectively, with an ash (4.8+/-0.7%) and nondigestible fiber (22.2%) content. Other bioactives found somewhat exclusively in hempseeds include:
Cannabidiolic acid  and its parent molecule, Cannabidiol (both nonintoxicating)
N-trans-Caffeoyltyramine at 33mg/g (3.3%) of a 60% methanolic extract 
With compounds not seen as unique to hemp including:
Much hemp oil can be extracted from the seeds via cold-processing and sold as its own nutritional supplement, the product after cold-processing is known as seed cake or seed meal and is approximately 10% fatty acids (oil) by weight with a comparably high protein content (30-50%).  
When looking at the fatty acid composition overall, it appears to contain:
Linoleic acid as omega-6 (56%)
Alpha-linoleic acid as omega-3 (22%)
Oleic acid (9%)
Palmitic acid (5%)
Gamma-linoleic acid (4%)
Stearic acid (2%)
Stearidonic acid (2%), an omega-3 fatty acid with the designation 18:4
The omega-6 and omega-3 ratio appears to be between 3:1 and 2:1, and Hemp is one of the few sources of Stearidonic acid (the other common source being blackcurrant oil).
Hemp seeds are fairly balanced in their macronutrient profile, and extraction of fatty acids to produce hemp oil leads a seed meal as byproduct; this seed meal is higher in protein (30-50%) and used as 'hemp protein'. The seeds are surprisingly low in sodium, and have a somewhat balanced omega fatty acid profile; like many plants, they may have a few unique polyphenolics or bioactives in them (these are cannabinoid compounds, although the psychoactive THC in Marijuana is not present in high amounts in commerical hemp anymore)
The composition of the seed meal appears to be:
Around 1700kJ (406kcal) per 100g
40.7+/-8.8% protein content
10.2+/-2.2% fatty acid content
6.7+/-1% ash content
26.3% nondigestible fiber
Arginine 94−128 mg/g
When comparing the amino acid profile against other sources, Hemp is comparatively high in Arginine and Tyrosine (greater than all other common sources tested) and is high in Alanine and Aspartic acid alongside Soy (both being greater than other sources).
The protein of hemp appears to be incomplete as, although it contains all essential amino acids, some are in insufficient quantity to provide the bare minimum of essential human nutrition; The limiting amino acids in Hemp appear to usually be Lysine, with Leucine and L-Tryptophan being the second and third limiting amino acids.  This makes it, from a complementary protein perspective, having comparable insufficiencies as grain products. 
In assessing the digestability of the protein from 30 samples of hemp (hempseed either hulled or dehulled as well as seedmeal) using a rat bioassay and rating the score via PDCAAS noted a digestability of approximately 86.7% (the reference protein, casein, scored 97.6%) when looking at the seed meal.  It appears that using dehulled seeds, prior to extraction of the oil, had a comparable absorption to casein (94.9+/-3.5%)  and according to PDCAAS (reference of casein at 100) Hemp scored between 50 and 60, comparable to lentils, due to the deficient quantity of Lysine. 
Hemp protein appears to be an incomplete amino acid source, but has decent protein absorption rates. Comparatively high in Arginine and Tyrosine and low in Lysine and Leucine
The two main cannabinoids in Hemp as a food product, Cannabidiol and its metabolite Cannabidiolic acid, are not agonists of the cannabinoid receptors (CB1 and CB2)  although cannabidiol may be able to act as an inverse agonist at 1µM  and impair the actions of other agonists at lower concentrations.  As mentioned earlier, legally produced hemp must contain less than 0.3% Delta-9-THC by weight and is unlikely to confer the psychoactive properties of this molecule (which are causative of the known effects of Marijuana).
Due to depletion of THC, there are not any major intoxicating effects of hemp protein which would mostly be due to the THC content. Cannabidiol retains the potential to impair the activity of other agonists at the CB1 receptor
Hempseed extract, in vitro, appears to activate calcineurin in a concentration dependent manner with maximal activity at 10mg/mL increasing activity by 35+/-5%. 
Oral ingestion of 200-800mg/kg hempseeds to mice for 7 days, where anti-memory agents (sodium nitrate, high acute dose of alcohol, and scopolamine) were introduced on days 8-10 during cognitive tested noted that preloading with all doses appeared to have anti-amnesiac effects (the best dose seemed to vary widely depending on test). 
May have minor pro-cognitive effects at higher doses, bioactive mediating these effects is not yet known (if a cannabinoid, then it may be novel to hemp protein supplementation; if due to an amino acid, this may apply to protein in general)
A rat study using ovariectomized rats (research model of menopause) using 1%, 5%, or 10% hempseed in the diet appeared to reduce menopause-related anxiety at all groups in a dose-dependent manner relative to control; the increase in serum cholesterol (including HDL) and calcium seen in ovariectomized control was similarly reduced with hempseed ingestion. 
At least one study suggests benefit to menopausal rats, active component not known
Hempseed has been investigated for its cardiovascular effects, particularly the fatty acid fragment.  Dietary inclusion of hempseed at 5-10% expectedly gives rise to plasma omega-6 and omega-3 concentrations in animals and may reduced platelet aggregation secondary to that;   an effect attributed to omega fatty acids in general. 
The oil from hempseed given to otherwise healthy persons at 30mL on top of a regular diet for 4 weeks noted a reduction in triglycerides (1.23+/-0.64mmol/L to 1.03+/-0.44mmol/L) which was also observed with the other group given flaxseed; there was no observable change of HDL-C nor LDL-C with either treatment,  and this lack of efficacy on LDL-C and HDL-C was replicated elsewhere with 12 weeks of hempseed oil ingestion at 2g daily (although this study also noted a lack of effect on triglycerides). 
There may be minor heart protective effects secondary to reducing clotting potential, but these are attributed to the omega-6 and omega-3 fatty acid content (up to 10% in hempseed protein) and not solely unique to this product. Linoleic and Alpha-Linonelic acid are common fatty acids in nature
Cannabidiolic acid appears to be a selective COX-2 inhibitor, although fairly weak with an IC50 of 2mM on COX-2 and 9.1-fold selectivity for COX-2 over COX-1. 
Unlikely to be biologically relevant due to the high concentration required paired with the low oral intake of cannabidiolic acid in hempseed meal
Cannabidiolic acid and its parent molecule Cannabidiol appear to have anti-migration properties on invasive MDA-MB-231 cells, with 5μM ; this appeared to be independent of COX2 inhibition (noted with these molecules), and appears to be due to activation of RhoA due to inhibiting its phosphorylation (possibly downstream of PKA inhibition). 
Oral ingestion of 30mL hempseed oil over 8 weeks relative to placebo (olive oil) in persons with atopic dermatitis noted that there was a trend to reduce transepidermal water loss (TEWL) in persons using hempseed from 12.2+/-5.3 at baseline to 9.6+/-3.7, although this failed to reach statistical significnace; the decrease in subjective skin dryness and itchiness did reach significance in the hempseed oil group. 
Possible benefits against atopic dermatitis associated with the fatty acid fragment of hempseed oil, may not be unique to hempseed
- Rodriguez-Leyva D, Pierce GN. The cardiac and haemostatic effects of dietary hempseed. Nutr Metab (Lond). (2010)
- House JD, Neufeld J, Leson G. Evaluating the quality of protein from hemp seed (Cannabis sativa L.) products through the use of the protein digestibility-corrected amino acid score method. J Agric Food Chem. (2010)
- Ross SA, et al. GC-MS analysis of the total delta9-THC content of both drug- and fiber-type cannabis seeds. J Anal Toxicol. (2000)
- Holler JM, et al. Delta9-tetrahydrocannabinol content of commercially available hemp products. J Anal Toxicol. (2008)
- Chen T, et al. The isolation and identification of two compounds with predominant radical scavenging activity in hempseed (seed of Cannabis sativa L.). Food Chem. (2012)
- Luo J, et al. Extract from Fructus cannabis activating calcineurin improved learning and memory in mice with chemical drug-induced dysmnesia. Acta Pharmacol Sin. (2003)
- Hempseed as a nutritional resource: An overview.
- Takeda S, et al. Cannabidiolic acid, a major cannabinoid in fiber-type cannabis, is an inhibitor of MDA-MB-231 breast cancer cell migration. Toxicol Lett. (2012)
- Chen T, et al. Cannabisin B induces autophagic cell death by inhibiting the AKT/mTOR pathway and S phase cell cycle arrest in HepG2 cells. Food Chem. (2013)
- The nutritive value of hemp meal for ruminants.
- Silversides FG, Lefrançois MR. The effect of feeding hemp seed meal to laying hens. Br Poult Sci. (2005)
- Characterization, amino acid composition and in vitro digestibility of hemp (Cannabis sativa L.) proteins.
- Girgih AT, Udenigwe CC, Aluko RE. Reverse-phase HPLC Separation of Hemp Seed (Cannabis sativa L.) Protein Hydrolysate Produced Peptide Fractions with Enhanced Antioxidant Capacity. Plant Foods Hum Nutr. (2013)
- Bisogno T, et al. Molecular targets for cannabidiol and its synthetic analogues: effect on vanilloid VR1 receptors and on the cellular uptake and enzymatic hydrolysis of anandamide. Br J Pharmacol. (2001)
- Thomas A, et al. Cannabidiol displays unexpectedly high potency as an antagonist of CB1 and CB2 receptor agonists in vitro. Br J Pharmacol. (2007)
- Saberivand A, et al. The effects of Cannabis sativa L. seed (hempseed) in the ovariectomized rat model of menopause. Methods Find Exp Clin Pharmacol. (2010)
- Prociuk MA, et al. Cholesterol-induced stimulation of platelet aggregation is prevented by a hempseed-enriched diet. Can J Physiol Pharmacol. (2008)
- Richard MN, et al. Dietary hempseed reduces platelet aggregation. J Thromb Haemost. (2007)
- Simopoulos AP. The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases. Exp Biol Med (Maywood). (2008)
- Schwab US, et al. Effects of hempseed and flaxseed oils on the profile of serum lipids, serum total and lipoprotein lipid concentrations and haemostatic factors. Eur J Nutr. (2006)
- Kaul N, et al. A comparison of fish oil, flaxseed oil and hempseed oil supplementation on selected parameters of cardiovascular health in healthy volunteers. J Am Coll Nutr. (2008)
- Takeda S, et al. Cannabidiolic acid as a selective cyclooxygenase-2 inhibitory component in cannabis. Drug Metab Dispos. (2008)
- Callaway J, et al. Efficacy of dietary hempseed oil in patients with atopic dermatitis. J Dermatolog Treat. (2005)