Hemp Seeds Protein: How Much, and How Good Is It?

How much protein is in hemp seeds?

Hulled hemp seeds contain 31.6 g of protein per 100 g. USDA FoodData Central lists that figure for “Seeds, hemp seed, hulled”, the product sold as hemp hearts.

A 30 g serving supplies 19% of FDA’s 50 g Daily Value for protein. That percentage is a plain weight calculation by this site. It does not adjust for protein quality, covered below.

Hemp hearts are also a high-fat food. Each 9.5 g of protein comes with 14.6 g of fat.

Whole hemp seeds have less protein

Whole seeds are about 24 to 25% protein, against about 32 to 36% for hulled seeds. The fibrous hull dilutes the protein.

USDA has no SR Legacy record for whole hemp seeds. The whole-seed numbers come from published analyses:

At 24 to 25%, a 30 g portion of whole seeds would hold roughly 7.2 to 7.5 g of protein. That range is arithmetic from the papers above, not a label value. More on the two forms: hemp hearts vs hemp seeds.

Amino acid profile

Hulled hemp seed contains all nine essential amino acids, and USDA lists an amount for each. Arginine, which is not one of the nine, is the most notable: 4.55 g per 100 g, or 14% of the protein.

The table compares the USDA amounts with the reference pattern used for PDCAAS. The pattern is the FAO/WHO one for children aged 2 to 5, as reproduced by Health Canada. A ratio below 1.00 means the protein falls short of the pattern for that amino acid.

The “mg per g protein” and ratio columns are this site’s calculation: USDA amino acid amounts divided by 31.6 g of protein, then by the reference value. Lysine is the only amino acid under 1.00.

Callaway (2004) names the two main proteins in hempseed as edestin and albumin. He describes both as easily digested storage proteins and notes the seed’s exceptionally high arginine level.

Protein quality: the PDCAAS figures

Hulled hemp seed has a PDCAAS of 63 to 66%, measured by House, Neufeld and Leson in 2010. The study appeared in the Journal of Agricultural and Food Chemistry and is the main reference for hemp protein quality.

PDCAAS stands for protein digestibility-corrected amino acid score. Health Canada’s method page gives the formula: the lowest amino acid ratio multiplied by true protein digestibility. Scores above 1.00 are cut to 1.00.

The team tested 30 commercial hemp products grown in Western Canada. Digestibility was measured with a rat bioassay, against the FAO/WHO pattern for children aged 2 to 5.

Three findings from the abstract matter here:

1. Lysine was the first limiting amino acid in all products. That matches the 0.70 ratio in the table above.
2. Removing the hull improved digestibility and PDCAAS.
3. Hemp protein scored equal to or higher than certain grains, nuts and some pulses. The abstract does not name them, so this page does not either.

What a PDCAAS of 63 to 66% means

It means hemp protein, eaten alone, covers about two thirds of the reference lysine need per gram of protein after digestion. It does not mean a third of the protein is wasted.

The score rates one food in isolation, and diets mix protein sources. The reference pattern is built on the needs of children aged 2 to 5.

Two limits of the evidence: the digestibility data come from rats, not people, and the samples were commercial products grown in Western Canada. Mierlita (2026) used a lab (in vitro) method and found 86.73% digestibility for hulled seeds against 78.34% for whole seeds, the same direction as House.

Hemp seeds protein compared with other seeds

Hemp hearts have the most protein of the six seeds in USDA’s data, just ahead of pumpkin seed kernels. They have nearly twice the protein of chia seeds per gram.

This table compares quantity only. This site has not sourced PDCAAS values for the other five seeds, so it does not rank them on quality.

The trade-off is fiber. Chia and flaxseed carry far more of it. The seed nutrition comparison tool shows every nutrient for all six, and hemp seeds vs chia seeds covers that pairing.

Hemp protein powder in brief

Hemp protein powder has more protein per gram than the seeds, but the one PDCAAS study scored the closest product lower. House and colleagues measured hemp seed meal, the material left after cold-pressing the oil. It averaged 40.7% protein and 10.2% fat.

Its protein digestibility was the highest of the three products at 90.8 to 97.5%. Its PDCAAS was 46 to 51%, below dehulled seed. The meal samples also varied widely in protein: the standard deviation was 8.8 percentage points.

In the US, FDA reviewed a GRAS notice for hemp seed protein powder (GRN 771) and had no questions, in December 2018. Retail powders differ in protein content, so the label on the tub is the number to use.

What the evidence does not show

No study cited here tests hemp seed protein for muscle gain, weight loss or any health outcome in people. The data cover composition and a rat-based quality score.

For the full nutrient tables, see hemp hearts nutrition. For what is and is not established about health effects, see hemp hearts benefits.