Nutrition · Guide
How to Buy Protein Powder
It is food, not a supplement. Buy on cost per gram of protein, third-party testing, and whether you will actually drink it.
By Julien Malet, · Updated 2026-09-07
Protein powder has no metabolic advantage over chicken, eggs, dairy or lentils. It is a convenient, cheap, shelf-stable way to add 25 g of protein without cooking. That is the entire case for it, and it is a good enough one.
Which means the buying decision is simpler than the marketing suggests.
Step one: cost per gram of protein
Not price per tub. Not price per serving. Price ÷ (servings × grams of protein per serving).
A $40 tub with 30 servings at 24 g each contains 720 g of protein: 5.6 cents per gram. A $60 tub with 25 servings at 21 g is 525 g: 11.4 cents per gram — twice the price for the same thing.
Good value is roughly 4–7 cents per gram. Above about 10, you are paying for branding.
This is the same arithmetic as cost per serving on any supplement, and protein is where the spread is widest.
Step two: pick a type
Whey concentrate — 70–80% protein, retains some lactose and fat, cheapest per gram, tastes best. The default for most people.
Whey isolate — 90%+ protein, most lactose removed. Worth it if you are lactose-sensitive or want the lowest calories per gram. Otherwise a premium for very little.
Casein — slower digesting. The "before bed" pitch is oversold; total daily intake dominates. Thicker texture, some people prefer it.
Plant blends (pea + rice) — pea is low in methionine, rice is low in lysine; together they are complete. A blend is fine. Single-source pea alone is adequate but not optimal.
Collagen — not a complete protein. No tryptophan, low in several essential amino acids. It does not count toward a muscle-protein target. There is some evidence for skin and joint endpoints, but it is a different product for a different purpose and should not be your protein source.
Hydrolysed / "fast absorbing" — pre-digested for marginally faster absorption. Absorption speed is not a limiting factor for anyone eating protein across a day. Skip.
Step three: check the label properly
Protein per serving vs scoop size. "26 g protein" at a two-scoop serving is a different product from 26 g at one. Check which.
Watch for amino spiking. Adding cheap free-form amino acids — glycine, taurine, creatine — raises measured nitrogen and therefore the stated protein number, without adding usable complete protein. Signs: those aminos listed separately, or a suspiciously cheap product with a high protein claim. It is less common than it was but has not disappeared.
Third-party testing matters more here than in most categories. Protein powders are consumed in large quantities daily, and independent testing has repeatedly found heavy metals — lead, cadmium, arsenic — in some products, with plant-based powders often higher because plants take up metals from soil. Look for NSF Certified for Sport or Informed Sport, and verify in the certifier's database rather than trusting the logo. What each seal verifies.
Added sugar. Some products carry 10–15 g. Check the panel.
Proprietary blends have no business in a protein powder. If there is one, walk. Why.
Step four: will you drink it?
The best-value tub you find revolting is worse value than a slightly pricier one you finish. Buy a single-serving sachet or the smallest tub first — flavour preference is unpredictable and a 5 lb tub of something you dislike is a expensive lesson.
What to ignore
- "Grass-fed" whey. No demonstrated difference in the protein.
- Added BCAAs. Whey already contains them. Redundant.
- Added digestive enzymes. Little evidence of benefit for most people.
- "Anabolic," "mass," "gainer." Usually protein plus cheap maltodextrin at a premium. Buy protein and buy carbohydrates separately if you want them.
The summary
Whey concentrate, third-party tested, 4–7 cents per gram of protein, in a flavour you like. That is the decision. The remaining variable is how much you actually need.