Whey protein guide: concentrate, isolate and hydrolysate
What whey protein is, the difference between concentrate, isolate and hydrolysate, and how to choose the right one.
What is whey protein?
Whey is the liquid part of milk left after cheese is made. It is filtered and dried into a powder that is rich in protein and in essential amino acids, including leucine. It mixes easily with water or milk, which makes it one of the simplest ways to add protein to your day.
The three main types
| Type | Protein per 100 g (typical) | Good for |
|---|---|---|
| Concentrate | About 70 to 80 g | Best value; a little lactose, fat and carbs |
| Isolate | About 90 g | Very low lactose, fat and carbs; popular while cutting |
| Hydrolysate | About 80 to 90 g | Pre-digested; easy on the stomach; usually the most expensive |
Many products blend concentrate and isolate. Always read the nutrition label: protein per scoop, calories, sugar and serving size differ between brands.
How to choose
- On a budget or bulking: concentrate or a blend.
- Cutting or sensitive to lactose: isolate.
- Stomach discomfort with other powders: hydrolysate or isolate.
How it fits your day
Research summarised by the ISSN and a large meta-analysis show that protein supplements add to the gains from resistance training when total daily protein is low. One scoop usually gives 20 to 30 g of protein. Use it to fill the gap between your meals and your daily target, which you can find with our protein calculator.
Who should be careful
People with a milk allergy should avoid whey. People with kidney disease should ask their doctor before increasing protein.
Frequently asked questions
Is whey isolate better than concentrate?
Not better, just purer: isolate has more protein per gram and less lactose, fat and carbs, and costs more. Concentrate gives similar protein per serving at a lower price.
Can I take whey on rest days?
Yes. Your daily protein target applies on rest days too, so a shake can help on any day you fall short.
Water or milk?
Both work. Water keeps calories low; milk adds protein and calories, which helps when bulking.
Scientific references
- Journal of the International Society of Sports Nutrition. International Society of Sports Nutrition Position Stand: protein and exercise (Jäger et al.) (2017-06-20) — PMID: 28642676 · DOI: 10.1186/s12970-017-0177-8
- British Journal of Sports Medicine. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults (Morton et al.) (2018-03-01) — PMID: 28698222 · DOI: 10.1136/bjsports-2017-097608
- NIH Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health Professionals
Related articles
Educational content based on the references listed. This article gives no dosing or usage instructions and does not replace professional medical advice.