Protein powders — plant-based (pea, rice, soy, hemp, blends)

Plant protein powders 2026 — completeness, heavy metals and the single-source problem

Nine of the most-bought plant protein powders ranked on amino completeness, leucine per serving, published heavy-metal testing and honest cost per gram of usable protein

Plant protein has a chemistry problem and a testing problem, and the marketing addresses neither. The chemistry problem: pea protein is short on methionine, rice protein is short on lysine, hemp is short on both and low in total protein, and only soy arrives complete on its own. Blend pea with rice and you fix it — which is why the good products are blends and the bad ones are single-source with a leaf on the tub. The testing problem is heavier: plants concentrate what the soil gives them, and repeated Clean Label Project assays have found measurably more cadmium and lead in plant protein powders than in whey. The brands that publish per-batch heavy-metal certificates are doing the one thing that actually matters in this category, and there are fewer of them than you would hope.

What it claims

'Complete plant protein with all 9 essential amino acids'
'Organic, non-GMO, clean, easy to digest'
'Same muscle-building results as whey'
'Gut-friendly with added enzymes and probiotics'
'Third-party tested for purity'

What the label is not telling you

'Complete' on a plant tub usually means 'contains all nine', not 'contains enough of all nine'. Every plant protein technically contains all essentials. What matters is whether the limiting amino acid clears its requirement at your serving size. Pea protein's methionine and rice protein's lysine are the two that fail. A pea+rice blend, or pea+pumpkin+sunflower, fixes it. Single-source pea at 20g does not, and the label will still say complete.
Leucine per serving runs 15–25% lower than whey at the same protein number. A 25g plant scoop typically lands at 1.8–2.3g leucine versus whey's 2.5–3.2g. The practical fix is unglamorous: take 30–40g instead of 25g. Every serious paper on plant-versus-animal protein equivalence (Pinckaers 2023 is the cleanest) reaches the same conclusion — plant protein matches animal protein when the dose is raised enough to match the leucine.
Heavy metals are the real risk axis and the industry mostly stays quiet. Rice protein is the worst offender for inorganic arsenic; cacao-flavoured SKUs add cadmium; pea is generally cleaner but soil-dependent. Consumer Reports' 2018 and Clean Label Project's repeated assays both found plant powders averaging higher than whey. Ask for a per-batch certificate. If a brand will not publish one, that is your answer.
'Organic' says nothing about heavy metals. Cadmium and lead are geological, not agrochemical. An organic certification and a clean heavy-metal assay are unrelated documents, and only one of them is on the front of the tub.
Digestive enzyme and probiotic add-ins are usually decorative. The probiotic dose in a protein powder is typically 1 billion CFU of a strain with no protein-specific evidence, sitting on a shelf at room temperature for a year. The enzyme blends are more defensible for pea protein's bloating, but the doses are rarely disclosed.
Soy is the one complete single source, and the phytoestrogen panic is not supported. Messina's reviews and the 2020–2024 meta-analyses find no adverse effect of soy isoflavones on testosterone or thyroid function at dietary and supplemental doses. Soy protein isolate is cheap, complete, well tested and unfashionable — a combination that usually means it is the value pick.
Ritual Essential Protein 18+ (€45 / 20 servings) — Pea plus organic pumpkin seed, ~20g protein, ~2.2g leucine, published third-party heavy-metal testing, added choline. Best-documented product in the category. Take 1.5 scoops if muscle is the goal.
Vega Sport (€45 / 20 servings) — Pea, brown rice and sacha inchi, ~30g protein, ~2.5g leucine, NSF Certified for Sport on some SKUs. The best training-focused plant option. Texture is chalky; the amino profile is genuinely complete.
Garden of Life Sport (€50 / 19 servings) — Organic multi-source blend, NSF Certified for Sport, ~30g protein. Good certification, high price per serving.
Form Performance / KOS (€40–50) — Well-formulated multi-source blends, good flavour work, testing disclosure thinner than Ritual's.
Orgain Organic (€30 / 20 servings) — Widely available, pea-rice-chia blend, ~21g protein. Fine value; heavy-metal disclosure is weaker than the premium tier and it has appeared in third-party testing controversies.
Sunwarrior / single-source rice or hemp SKUs (€35–45) — Incomplete on their own and rice-based products carry the highest arsenic risk in the category. Use as an ingredient in a blend, not as your only protein.
Supermarket soy protein isolate (€15–25 / 30 servings) — Complete, ~27g protein, ~2.2g leucine, unfashionable, cheapest correct answer in the category if you tolerate soy.

Effect on the nervous system

This is where the plant-protein conversation gets genuinely interesting, and it is not about muscle. The amino acids that build nervous-system infrastructure are exactly the ones single-source plant proteins run short of. Methionine and cysteine feed glutathione, the brain's main oxidative buffer — and pea protein is short on methionine. Lysine is required for carnitine synthesis and mitochondrial fat transport — and rice protein is short on lysine. Tryptophan sets the ceiling on serotonin production, most of which happens in the gut and is read by vagal afferents. So the person eating 90g of protein a day entirely from a single-source pea powder can be hitting their total and still short on the two inputs their oxidative buffering and their mitochondria depend on. That is the mechanism behind a pattern we see constantly: someone goes plant-based, tracks protein diligently, and six months later reports flatter mood, worse sleep and a fuse that shortened without explanation. Total was fine. The profile was not. Plant protein done properly — blended, dosed at 30–40g, with a B12 and omega-3 plan alongside — is a completely legitimate way to feed a nervous system. Done as a single-source scoop with a leaf on the tub, it is a slow deficit with good branding.

Who it might suit

Vegans and vegetarians, obviously — with a blend, not a single source. Anyone with cow's-milk protein allergy. Anyone who finds whey genuinely uncomfortable. People with an ethical or environmental preference, which is a perfectly good reason as long as the amino maths is respected.

Who should skip it

Anyone relying on single-source pea, rice or hemp as their only protein. Anyone who will not raise the dose to 30–40g. Pregnant people and children should be especially careful with rice-based powders because of inorganic arsenic. And anyone buying a plant powder from a brand that will not publish a heavy-metal certificate — in this category that document is the product.

Bottom line

Plant protein works when you respect two rules: buy a blend, not a single source, and take 30–40g, not 25g. Best documented: Ritual Essential Protein. Best for training: Vega Sport. Best value: plain soy protein isolate, which is complete and cheap and nobody wants to say so. Avoid: single-source rice as a primary protein. Then close the two gaps a tub cannot: B12 and omega-3. The amino-profile review has the completeness maths in full, the Recovery Anchor sets the training side, and the Nervous System Journal is where you find out whether your profile — not just your total — is actually adequate.