Amino Acids

Protein Powder

Supplementary protein is well-studied. The source on the tub changes what you're actually paying for.

Protein powder is the most everyday supplement in the category, and the reference meta-analysis on it establishes that adding protein to a training programme meaningfully improves lean mass and strength up to roughly 1.6g per kilogram of body weight per day — above that, the extra doesn't add much. Whey isolate is the fastest-absorbing option and highest in the branched-chain amino acid leucine; whey concentrate is the same source at a lower cost with more lactose; casein digests slowly and is the classic before-bed option. Plant sources like pea, soy, rice, and hemp cover vegetarian and vegan needs, with soy and pea carrying the strongest amino acid profiles among them. Collagen protein has its own uses for skin and joints but is a poor choice for building muscle, because it lacks meaningful leucine.

Forms and bioavailability

Not all forms are absorbed equally. The form on your supplement label affects how much your body can actually use.

FormAbsorptionWith foodTimingEvidence
whey protein concentrateTypicalEitherEitherStrong
egg white proteinHigherEitherEitherLikely
collagen proteinTypicalEitherEitherLikely
soy protein isolateTypicalEitherEitherLikely
pea protein isolateTypicalEitherEitherLikely
hemp proteinLowerEitherEitherPossible
rice proteinTypicalEitherEitherLikely
casein (micellar)TypicalEitherEveningStrong
whey protein isolateHigherEitherEitherStrong

How it pairs with other supplements

Works well with

CreatineStrong

Protein provides the amino acid substrate while creatine enhances ATP resynthesis; combined benefits for lean mass and strength exceed either alone (Cribb et al. 2007).

Stack Almanac tracks your protein source and daily total, and highlights the classic pairing with creatine — the two have been studied together enough that treating them as separate purchases misses the combined effect.

Track your Protein Powder in Stack Almanac

Last reviewed: 2026-07-22. Reference values are adult-general RDAs. Individual needs may vary. This page is for informational purposes only and is not a substitute for professional medical advice.