Pea protein is the most common type of protein used in plant-based protein powders.
If you’re relying more on pea protein, it’s good to know the strengths and weaknesses of its amino acid profile so you know what to combine it with.
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The Complete Amino Acid Profile of Pea Protein
The following graph shows a the typical amino acid profile of pea protein. Essential amino acids have a little asterisk next to their names.
This graph was generated using our amino acid profile comparison tool.
It might be easier to read in table form with just the amino acids.
The “complete protein” column shows you the minimum percent of total protein a specific essential amino acid should be (taken from Wikipedia). The “pea protein” column shows you the percent of total protein that there is of each amino acid in pea protein.
| Complete Protein (min %) | Pea protein (%) | |
|---|---|---|
| Histidine | 1.8 | 2.5 |
| Isoleucine | 2.5 | 4.8 |
| Leucine | 5.5 | 8.5 |
| Lysine | 5.1 | 7.5 |
| Methionine+Cysteine | 2.5 | 1.9 |
| Phenylalanine+Tyrosine | 4.7 | 5.5 |
| Threonine | 2.7 | 3.7 |
| Tryptophan | 0.7 | 1 |
| Valine | 3.2 | 5 |
Pea protein exceeds the minimum for all of the essential amino acids except for methionine/cysteine, although it’s not short by much.
Therefore, pea protein is not a complete protein. This isn’t a huge deal since no one eats 100% of their protein in the form of pea protein, but something to be aware of.
If you’re buying a plant-based protein powder, consider buying one with a blend of pea and other protein sources.
Pea protein has a great amino acid profile, that’s why it’s the most popular protein source in vegan protein powders. However, it’s a bit low in methionine + cysteine, which is why many plant-based protein powders also add in some other ingredient like brown rice protein powder as well.
Pea Protein vs Whey Protein: Amino Acid Comparison
We can compare pea protein to whey protein’s amino acid profile to see how they stack up.
They’re pretty similar except for a few differences.
| Complete Protein (min %) | Pea protein (%) | Whey protein (%) | |
|---|---|---|---|
| Histidine | 1.8 | 2.5 | 1.7 |
| Isoleucine | 2.5 | 4.8 | 6.4 |
| Leucine | 5.5 | 8.5 | 10.6 |
| Lysine | 5.1 | 7.5 | 9.6 |
| Methionine+Cysteine | 2.5 | 1.9 | 4.4 |
| Phenylalanine+Tyrosine | 4.7 | 5.5 | 5.6 |
| Threonine | 2.7 | 3.7 | 6.7 |
| Tryptophan | 0.7 | 1 | 1.4 |
| Valine | 3.2 | 5 | 5.9 |
You can see why whey protein is the gold standard of protein powders. It easily exceeds the minimum needed to be a complete protein in all categories except histidine.
Even though whey protein in the table above is 0.1% shy on histidine, almost everyone would say that whey is a complete protein. That small difference can be explained by rounding errors, and the amount will change slightly based on the batch the sample is from.
Compared to whey protein, pea protein is relatively:
- High in arginine
- High in glycine
- High in phenylalanine
- Low in methionine* and cysteine
- Slightly low in leucine*, isoleucine*, and lysine*
Peas are lower in those 3 essential amino acids, but if you look at the chart or table, you can see that it’s by a very small amount.
Pea protein is very comparable to whey protein’s amino acid profile when you look at the overall profile. However, it turns out that pea protein is also the closest vegan alternative to casein protein.
While whey protein does have a slightly “stronger” amino acid profile than pea protein, they’re quite comparable. Note that whey protein is high in the 3 BCAAs (leucine, isoleucine, and valine), which are typically desirable for muscle synthesis.
Is Whey Protein Better Than Pea Protein?
We’ve noted that whey has a slightly more balanced amino acid profile and also has more branched chain amino acids.
And while this might make a difference if you were only consuming protein powder and nothing else, there is not sufficient evidence showing any difference in muscle growth based on drinking whey or pea protein shakes.
A double-blind, randomized, and placebo-controlled study over 12 weeks with 161 subjects found that while subjects gained muscle mass:
Since no difference was obtained between the two protein groups, vegetable pea proteins could be used as an alternative to Whey-based dietary products
On top of that, there are quite a few huge vegan bodybuilders these days that show that there’s nothing that “special” about animal proteins other than they can be more convenient for the average person to consume.
Research suggests that there’s no significant difference between the results from pea vs whey protein powder in the context of typical usage.
The Best Foods to Pair With Pea Protein
Most people don’t need to do anything special to get enough methionine from other foods in their diet to be worried about it.
But if you’re really serious about building muscle or athletics, you might want to know which other foods to consume alongside pea protein (it doesn’t have to be at the exact same time necessarily).
Here are the top 20 plant-based foods high in methionine:
| Food | Methionine (g) Per 100 grams |
|---|---|
| Seaweed (dried) | 1.14 |
| Brazil nut | 1.12 |
| Vital wheat gluten | 0.98 |
| Hemp seeds | 0.93 |
| Chia seeds | 0.59 |
| Sesame seeds | 0.59 |
| Pumpkin seeds | 0.42 |
| Flaxseed | 0.37 |
| Pistachio nuts | 0.36 |
| Peanuts | 0.32 |
| Oats | 0.31 |
| Cashew | 0.27 |
| Pine nuts | 0.26 |
| Walnut | 0.24 |
| Hazelnut | 0.22 |
| Pecans | 0.18 |
| Almonds | 0.16 |
| Rye grain | 0.15 |
| Buckwheat groats | 0.15 |
| Soybeans | 0.15 |
From the above data, it’s clear that most good plant sources of methionine are:
- Nuts
- Seeds
- Grains
Assuming you’re making a protein shake with your pea protein, you can just toss in some seeds or nut butter. Obviously it helps if you use a blender for this.
Pea protein can be paired with many plant-based foods if you’re really concerned about getting enough methionine and cysteine post workout. However, your body does have a floating pool of amino acids, so as long as you’re eating other protein sources during the day, it’s not something you really need to worry about.
