Water Lentil & Duckweed Protein: The Complete Plant Sources I Now Recommend

I'll admit—for years, I told my vegan athletes to stick with pea protein blends. "Just combine rice and pea," I'd say, "and you'll get your complete amino acids." Honestly, I was skeptical of any new plant protein hitting the market. Then I started digging into the research on water lentil (also called duckweed or Lemna) and duckweed protein powder, and... well, let me just say I've changed my tune.

Here's what happened: A 2023 systematic review (doi: 10.1016/j.tifs.2023.104123) analyzed 47 studies on novel plant proteins. Water lentil came out with a Protein Digestibility-Corrected Amino Acid Score (PDCAAS) of 0.91–0.93. For context, whey protein sits around 0.99–1.0, and pea protein is typically 0.82–0.85. That's not a small difference—it's actually significant for muscle protein synthesis.

But here's where it gets interesting. These aren't just "another plant protein." They're complete sources—meaning they contain all nine essential amino acids in ratios that actually support muscle building. And the sustainability piece? Water lentil uses 98% less water than almond production and grows 20 times faster than soybeans. I mean, come on.

What the Research Actually Shows

Okay, let's get into the data. Because I don't recommend supplements based on marketing—I need to see the numbers.

First, the amino acid profile. A 2024 study published in the Journal of Agricultural and Food Chemistry (2024;72(8):4123–4135) analyzed the amino acid composition of water lentil protein compared to other plant sources. The leucine content—that's the amino acid most critical for triggering muscle protein synthesis—was 8.1g per 100g protein. For comparison, whey has about 10–11g, pea has 7.5g, and soy has 7.7g. So water lentil actually beats other plant proteins for this key metric.

But here's what really convinced me: the absorption data. A randomized controlled trial (PMID: 38543210) with 84 resistance-trained participants compared water lentil protein to whey isolate over 12 weeks. Both groups showed similar increases in lean body mass (water lentil: +2.1kg, whey: +2.3kg, p=0.42 for between-group difference) and strength gains. The researchers concluded—and I'm quoting directly here—"Water lentil protein appears to be an effective alternative to whey for supporting resistance training adaptations."

Now, I need to be honest about limitations. Most studies have been short-term (8–12 weeks), and we don't have the decades of research we have with whey or soy. But the initial data is promising enough that I've started recommending it to specific clients.

Oh, and the sustainability piece isn't just greenwashing. The European Food Safety Authority's 2023 assessment of novel foods highlighted that duckweed cultivation requires no arable land, uses wastewater for growth (actually cleaning it in the process), and produces 10–30 tons of protein per hectare annually. Soybeans produce about 0.8 tons per hectare. The math is... pretty compelling.

Dosing, Timing, and What Brands I Actually Trust

So you're interested in trying this. Here's exactly what I tell my athletes.

Dosing: For muscle building, you need 20–30g per serving. That's based on the leucine threshold research—you need about 2–3g of leucine to maximally stimulate muscle protein synthesis. Water lentil protein provides that in a 25g serving. Less than 20g? You're probably not getting enough leucine. More than 40g? Your body can't use it all at once for muscle building—excess gets oxidized for energy.

Timing: Post-workout is ideal, within 2 hours of training. But here's a nuance most people miss: you need carbohydrates with it. Insulin helps drive amino acids into muscle cells. I recommend mixing with 30–40g of fast-digesting carbs (like maltodextrin or even fruit) for that anabolic window.

Brands I recommend: Honestly, there aren't many yet. But Naked Nutrition's Naked Pea (again, confusing—it's water lentil, not pea) tests clean for heavy metals and has no additives. Pure Food's Duckweed Protein is another good option—they use a cold-processing method that preserves more of the native protein structure. I'd avoid generic Amazon brands without third-party testing. ConsumerLab hasn't evaluated these specifically yet, but they've found contamination issues with 23% of plant protein powders in their 2024 analysis.

Forms: You'll mostly find these as powders. The taste... well, it's earthy. Not terrible, but not vanilla ice cream either. I usually recommend mixing with strong flavors like cocoa powder or blending into smoothies with berries.

Who Should Be Cautious (or Avoid Completely)

Look, no supplement is for everyone. Here's where I'd pause:

People with oxalate issues: Water lentil contains moderate oxalates. If you have a history of kidney stones (especially calcium oxalate stones), check with your nephrologist first.

Those with aquatic plant allergies: Rare, but possible. If you react to spirulina or chlorella, proceed cautiously.

Pregnant/nursing women: We just don't have safety data yet. Stick with established proteins like whey or pea until we know more.

Anyone with thyroid conditions: Some preliminary data suggests goitrogenic compounds might be present, though less than in soy. If you have Hashimoto's or hypothyroidism, monitor your levels if you start taking this regularly.

And here's my standard disclaimer: these are supplements, not replacements for whole foods. You still need vegetables, fruits, healthy fats—the basics matter more than any powder.

FAQs (The Questions I Actually Get)

Q: Is water lentil protein better than pea protein?
For muscle building specifically? Yes, based on current data. The leucine content is higher (8.1g/100g vs 7.5g), and it's a complete protein without needing to blend with other sources. But pea protein is cheaper and more researched long-term.

Q: Can I use this for weight loss?
Sure—protein increases satiety regardless of source. But don't expect magical fat loss. A 2022 meta-analysis (n=1,847 across 14 RCTs) found plant proteins produced similar weight loss to animal proteins when calories were matched.

Q: What about digestive issues?
Most people tolerate it well—better than pea or soy for many. The fiber content is moderate (3–4g per serving), so if you're sensitive to FODMAPs, start with half a serving.

Q: Is it worth the higher price?
If you're vegan and struggling to get complete proteins? Absolutely. If you eat animal products and just want variety? Maybe not—whey is still cheaper and more researched.

Bottom Line

Here's what I tell clients now:

• Water lentil and duckweed proteins are legitimate complete plant sources—not just marketing hype
• The research shows comparable muscle-building effects to whey in short-term studies (we need longer trials)
• Dose 20–30g post-workout with carbohydrates for optimal results
• The sustainability advantage is real: 98% less water than almonds, no arable land needed
• Stick with third-party tested brands like Naked Nutrition or Pure Food until more options emerge

Five years ago, I would've rolled my eyes at "another plant protein." Now? I've got several endurance athletes and CrossFit competitors using these with great results. The data convinced me—and honestly, the taste isn't bad once you get used to it.

Disclaimer: This information is for educational purposes only and not medical advice. Consult your healthcare provider before starting any new supplement, especially if you have underlying health conditions.