Casein protein powder
Values per 100 g — CIQUAL data (ANSES).
Photo: Pexels
The slow-digesting protein
Casein powder is a slow-digesting milk protein: ~78 g of protein per 100 g. Unlike whey (fast), it releases amino acids gradually over several hours — hence its classic use at night, to feed the muscle overnight.
It is not essential, but it is a convenient supplement for those who want a prolonged protein source, especially before bed.
Whey or casein?
Whey is ideal around training (fast digestion); casein suits prolonged fasting periods better (night, long hours without a meal). Many lifters only need whey; casein is a bonus, not a must. What matters most is your daily protein total.
How to use it
As a shake at night, or mixed into a dairy to thicken it. Its texture is thicker than whey. Natural casein-rich foods (fromage blanc, skyr, cottage cheese) offer the same 'slow' benefit without any powder.
Casein and sleep: what research shows
Studies on 'pre-sleep' protein suggest that around 30-40 g before bed can support muscle protein synthesis overnight. Casein fits this well thanks to its slow digestion, which spreads the amino-acid release over several hours.
Keep it in perspective: this benefit stays modest next to the essential thing, your daily protein total. If you already hit it, evening casein is a small bonus, not a necessity.
What to pair it with
Casein (or a casein-rich dairy) as an evening snack.
Key takeaways
- ~78 g protein per 100 g, slow-digesting: ideal at night.
- A supplement, not a must: the protein total comes first.
- Whey around training, casein for long meal-free stretches.
- Fromage blanc/skyr/cottage cheese = natural casein.
Frequently asked questions
Is casein essential?
No: a casein-rich dairy (fromage blanc, skyr, cottage cheese) provides the same slow protein. The powder is mainly a convenience, not a must.
Can you take whey and casein?
Yes: whey during the day and around training, casein rather at night. But the key remains hitting your daily protein total.
When should you take casein?
Most often before bed, or before a long stretch without a meal, to make use of its slow digestion. But timing is secondary: hitting your daily protein total matters far more than the exact moment.
Compute your needs and track your progress
Calorie, protein and macro calculators — free, no account.