Protein Powder Guide
Protein powder is convenient food, not a supplement with special properties. Here is how to choose one and when you genuinely need it.
Last updated: 1 July 2026
Overview
Protein powder is dried food. It is a convenient, cheap, high quality protein source with a long shelf life, and that is the entire pitch.
It does not build muscle better than chicken does. It builds muscle exactly as well as chicken does, and fits in a gym bag.
Quick Answer
Protein powder is a convenient protein source rather than a supplement with unique properties. Whey is the cheapest and best absorbed option, casein digests more slowly, and soy or pea blends work well for plant-based diets. You only need it if you struggle to hit your protein target from food.
Key Points
- Powder is food, not magic. Whole food works just as well.
- Whey concentrate is the best value for most people.
- Isolate is only worth the premium if lactose is a problem.
- Plant blends need to combine sources for a complete amino profile.
- Check protein per 100g, not per scoop.
The main types
| Type | Protein per 100g | Digestion | Best for |
|---|---|---|---|
| Whey concentrate | 70 to 80g | Fast | Most people, best value |
| Whey isolate | 85 to 90g | Fast | Lactose sensitivity, lower calorie |
| Casein | 75 to 85g | Slow | Before bed, longer satiety |
| Soy | 80 to 90g | Moderate | Plant-based, complete profile |
| Pea and rice blend | 75 to 85g | Moderate | Plant-based, blended for completeness |
Whey concentrate is the default recommendation. Isolate is more filtered, lower in lactose and slightly higher in protein per gram, at a noticeably higher price.
Plant-based options
Single plant proteins are often low in one or more essential amino acids. Pea is low in methionine, rice is low in lysine, and blends of the two solve both problems.
Soy is complete on its own. For plant-based lifters, either a soy powder or a pea and rice blend works well, and aiming slightly higher on total daily protein covers the remaining gap.
Reading a label
| What to check | Why |
|---|---|
| Protein per 100g | The real comparison figure |
| Serving size | Scoops vary from 25g to 40g between brands |
| Added carbohydrate | Some products are half maltodextrin |
| Amino spiking | Added glycine or taurine inflating nitrogen tests |
| Third party testing | Relevant if you are a tested athlete |
The per-scoop figure on the front is close to meaningless when scoops differ by 60 percent between products. Compare per 100g, and divide price by grams of protein rather than by kilogram of powder.
Do you need it
| Situation | Verdict |
|---|---|
| Hitting protein target from food comfortably | No need |
| Falling 30 to 50g short most days | Genuinely useful |
| Very busy, meals hard to organise | Useful |
| Plant-based and struggling to hit targets | Useful |
| Trying to gain weight and appetite is limiting | Useful in a shake with oats and milk |
There is no health or performance penalty for skipping it. There is also nothing wrong with using it daily.
Common Mistakes
| Mistake | Why it causes problems | Better approach |
|---|---|---|
| Comparing prices per kilogram | Ignores protein density | Compare cost per 100g protein |
| Replacing meals with shakes | Poor satiety, worse diet quality | Use it to top up, not replace |
| Buying based on flavour claims | Says nothing about quality | Check protein per 100g |
| Assuming it works better post-workout | Timing barely matters | Fit it wherever it helps |
| Ignoring the rest of the diet | A shake does not fix a poor diet | Whole foods first |
Frequently Asked Questions
Is whey better than plant protein?
Whey has a slightly better amino acid profile and leucine content, which gives it a small edge per gram. Plant proteins close the gap when blended and when total intake is slightly higher.
Do I need protein powder to build muscle?
No. Hitting your daily protein target matters; how you hit it does not.
Is casein better before bed?
It digests more slowly, which has a theoretical advantage overnight. In practice the effect is small and total daily protein matters far more.
How many shakes a day is too many?
There is no hard limit, but if more than a third of your protein comes from powder you are probably missing out on the fibre, micronutrients and satiety that whole foods provide.
Sources
British Dietetic Association food facts - https://www.bda.uk.com/food-health/food-facts.html
Journal of the International Society of Sports Nutrition - https://jissn.biomedcentral.com/
Examine independent supplement analysis - https://examine.com/