Benefits
Blood pressure compared with casein protein
In a double-blind crossover trial in 31 adults with mildly raised blood pressure, 50 g a day of hemp seed protein for 6 weeks gave 24-hour blood pressure about 3.5/2.9 mmHg lower than casein, and a version with added hemp peptides about 8.9/5.8 mmHg lower. It is one academic trial with short 2-week washouts, and a hemp company donated the powder.
Post-meal blood sugar and insulin response
In two acute crossover experiments (27 and 16 adults), a 20 or 40 g hemp protein drink before a pizza meal lowered the early blood sugar response compared with a carbohydrate drink, with a larger effect at 40 g. Soy protein did the same, and hemp and soy did not differ. These were single-dose lab tests, not long-term blood sugar outcomes.
Muscle thickness during resistance training
In an 8-week double-blind trial in 34 trained adults, 60 g a day of hemp powder (40 g protein) was compared with soy matched for protein. Arm muscle thickness rose with hemp in women and with soy in men, and men on hemp kept more muscle twitch force after a fatigue test. The abstract does not report an overall hemp advantage in lean mass or strength.
Fullness hormones after a hemp flour meal
In 10 adults who ate meals each supplying 30 g of protein from different plant flours baked into bread rolls or from beef, the hemp meal raised the fullness hormone GLP-1 more than the other plant meals and lowered the hunger hormone ghrelin compared with beef. Buckwheat, not hemp, gave the strongest reduction in hunger ratings. These were one-day tests in a very small group.
Blood fatty acids from hulled hemp seeds
In a 4-week double-blind crossover in 30 adults with a BMI of 25 to 35, 60 g a day of hulled hemp seeds plus 30 g of hemp oil raised ALA, GLA and DGLA in blood compared with sesame seeds and soybean oil. Blood lipids, glucose, insulin, blood pressure and body composition did not differ between the two diets.
Plant protein with lysine as the limiting amino acid
In laboratory analyses of commercial products, hulled hemp seed had a protein quality score (PDCAAS) of 63 to 66%, pressed seed meal 46 to 51% and whole seed 49 to 53%. Lysine was the first limiting amino acid in every product, and removing the hull improved digestibility. The digestibility part of the score was measured in rats.
Mechanism of action
Edestin-rich storage protein
Edestin, a legumin-type globulin, is the main protein in hemp seed. A protein isolate had essential amino acid levels similar to or higher than soy isolate except lysine, and lysine and the sulfur amino acids fell short of the FAO/WHO pattern for young children. Removing the fibrous hull raises protein digestibility.
Peptides that act on blood pressure enzymes
In lab and rat studies cited by the trial authors, hemp protein hydrolysates inhibited the blood pressure enzymes ACE and renin. In the human crossover trial, plasma ACE and renin activity were lower and nitric oxide higher after hemp protein than after casein, which fits this idea but does not prove it.
Protein slows the post-meal glucose rise
Taking protein before a meal blunted the early rise in blood sugar in a dose-dependent way in the acute hemp and soy experiments, with lower insulin at the 40 g doses. This appears to be an effect of protein in general rather than something unique to hemp.
Polyunsaturated fat in the hulled seed
Hulled hemp seeds are almost half fat by weight and supply polyunsaturated fats including linoleic acid, ALA, GLA and stearidonic acid. Pressing out the oil leaves a meal that is higher in protein and much lower in fat, so powders and hemp hearts deliver different nutrient mixes.
Clinical trials
Double-blind, randomized crossover trial of three 6-week treatments (50 g/day casein, 50 g/day hemp seed protein, or 45 g hemp seed protein plus 5 g hemp peptides) taken as smoothies, with 2-week washouts; 24-hour ambulatory blood pressure was the main outcome. Funded by the Heart and Stroke Foundation of Canada, with hemp powder donated by Manitoba Harvest (Samsamikor et al. 2024, Am J Clin Nutr)
35 adults with mild hypertension (systolic 130 to 160 mmHg) were randomized and 31 completed; mean age about 61, and 11 were taking blood pressure medicines.
At the end of each 6-week period, 24-hour blood pressure averaged 137.0/81.8 mmHg after casein, 133.5/78.9 mmHg after plain hemp protein and 128.1/76.0 mmHg after the peptide-enriched hemp protein; both hemp treatments were lower than casein (P < 0.0001). Both hemp treatments lowered plasma ACE and renin activity and raised nitric oxide versus casein. Six people had mild gas or stomach discomfort in the first 2 weeks.
Two acute randomized crossover experiments comparing 20 or 40 g of hemp protein, 20 or 40 g of soy protein and an isocaloric carbohydrate control taken before a pizza meal; Manitoba Harvest is listed as a collaborator on both trial registrations (Mollard et al. 2021, Appl Physiol Nutr Metab)
27 adults in experiment 1 and 16 adults in experiment 2.
Both protein types lowered the 0 to 60 minute blood sugar response compared with the control in a dose-dependent way, and in experiment 2 the 40 g hemp and soy doses lowered mean insulin before the meal compared with the 20 g doses and control. Hemp and soy did not differ. The abstract does not report a difference in food intake at the test meal.
Double-blind randomized trial of 60 g/day hemp powder (40 g protein, 9 g oil) or soy matched for protein and calories during 8 weeks of training about 4 times a week; lean mass by DXA, muscle thickness by ultrasound, strength, muscle twitch properties and inflammation markers (Kaviani et al. 2024, Eur J Appl Physiol)
34 resistance-trained young adults (22 men, 12 women).
Elbow flexor muscle thickness rose with hemp in women (2.6 to 3.1 cm, p = 0.012) and with soy in men (3.7 to 4.0 cm). Men on hemp kept twitch torque and rate of torque development after a fatigue test better than men on soy. The abstract reports no overall hemp advantage in lean mass or strength; results were sex-specific.
Six one-day acute interventions, each meal supplying 30 g of protein from buckwheat, fava bean, pea, hemp or lupin flour baked into bread rolls, or from beef, with blood sampling over 24 hours and appetite ratings over 5 hours (Neacsu et al. 2022, Eur J Nutr)
10 adults (3 men, 7 women), mean age 42, mean BMI 26.
The hemp meal raised GLP-1 more than the other plant meals (p = 0.01), and ghrelin was lower after the hemp meal than after beef. Buckwheat gave the lowest hunger scores at 300 minutes. With few exceptions, plasma amino acids after the plant meals did not differ significantly.
Randomized, double-blind crossover trial of 4 weeks of hemp foods (60 g/day hulled hemp seeds plus 30 g/day hemp oil, per the trial registration) versus a control of hulled sesame seeds and soybean oil (She et al. 2026, Food Funct)
30 adults aged 18 to 65 with normal blood sugar and a BMI of 25 to 35.
ALA, GLA and DGLA in plasma, and ALA, DGLA and EPA in red blood cells, were higher after the hemp foods. Serum lipids, glucose, insulin, blood pressure and body composition did not differ between treatments.
Double-blind, placebo-controlled randomized trial with four groups: hemp seed, hemp seed plus aerobic exercise three times a week, exercise plus placebo, or placebo; hemp seed was given as two 1 g capsules a day (Mohammadrezaei et al. 2022, J Food Biochem)
48 sedentary young men in Tabriz, Iran.
Hemp seed alone raised HDL cholesterol compared with baseline. Hemp seed with exercise changed weight, BMI, fat mass, HDL, catalase and BDNF from baseline, and fat mass, total and LDL cholesterol and BDNF differed between groups at the end. The 2 g daily dose is far below a protein serving, and most changes are reported within groups.