Casein Protein
Casein is a slow-digesting dairy protein used for muscle protein synthesis and satiety, especially overnight.
Overview
What is casein?
Casein is a protein found in milk. Cow's milk contains around 80% casein protein but it is also found in dairy products including cheese, yogurt and infant formulas.
Dosage
Casein protein can be used to supplement dietary protein intake. Typical protein intakes range from 0.8–2.0 g/kg/day. Athletes and highly active people may benefit from a protein intake towards the higher end of this range.
Effect graph
Effect heatmap
SupplementDEX Database
7 conditions for and rated at least stars. All purchase bands. No minimum star filter.
Database Snapshot
Most casein protein research is concentrated in a handful of conditions.
- Athletic performance accounts for 12 of 36 studies (33%).
- Obesity accounts for 9 of 36 studies (25%).
- Low birth weight accounts for 7 of 36 studies (19%).
- Sparse coverage remains for Diabetes, Blood sugar control, Physical function in older adults.
Safety
Casein may cause gastrointestinal side effects for people with lactose intolerance. Some people may be allergic to casein, which is found in milk.
Frequently Asked Questions
References
Sources35 references
SupplementDEX uses only high-quality sources to determine supplement effectiveness.
SupplementDEX Database · High blood pressure
4 references1.SupplementDEX Database: High blood pressure — Impacts of Milk Protein Supplementation on Lipid Profile, Blood Pressure, Oxidative Stress, and Liver Enzymes: A Systematic Review and Meta-analysis2025
A meta-analysis of 65 milk-protein RCTs found supplementation modestly improved lipids, blood pressure, oxidative stress, and liver enzymes in adults.
2.SupplementDEX Database: High blood pressure — Effects of high-quality protein supplementation on cardiovascular risk factors in individuals with metabolic diseases: A systematic review and meta-analysis of randomized controlled trials2024
A meta-analysis of 63 RCTs found soy, milk, whey, and casein proteins each modestly lowered blood pressure and improved some lipid measures in metabolic disease.
3.SupplementDEX Database: High blood pressure — Effects of milk proteins and combined exercise training on aortic hemodynamics and arterial stiffness in young obese women with high blood pressure2013
In 33 obese hypertensive women over 4 weeks, whey or casein plus exercise lowered brachial/aortic BP and arterial stiffness vs carbohydrate control.
4.SupplementDEX Database: High blood pressure — The chronic effects of whey proteins on blood pressure, vascular function, and inflammatory markers in overweight individuals2010
In 70 overweight adults over 12 weeks, whey and casein each lowered systolic and diastolic BP vs glucose control; lipid and inflammatory effects were modest.
5.SupplementDEX Database: Physical function in older adults — Effect of Protein Supplementation Combined With Resistance Training in Gait Speed in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials2024
A meta-analysis of 18 RCTs (1,147 older adults) found protein plus resistance training improved gait speed vs training alone, especially when protein followed exercise.
SupplementDEX Database · Low birth weight
7 references6.SupplementDEX Database: Low birth weight — Are babies more satisfied by casein based formulas?1989
An RCT of 173 infants found ~23% had formula changed by 6 weeks regardless of starting whey- or casein-dominant formula, arguing against inherent satiety differences.
7.SupplementDEX Database: Low birth weight — Growth and metabolic response of premature infants fed whey- or casein-dominant formulas after hospital discharge1989
In 19 preterm infants followed 6 months after discharge, whey- vs casein-dominant formula produced no significant differences in growth or biochemistry.
8.SupplementDEX Database: Low birth weight — Late metabolic acidosis and poor weight gain in moderately pre-term babies fed with a casein-predominant formula: a continuing need for caution1989
In 70 moderately preterm Chinese infants, casein-predominant formula caused persistent metabolic acidosis and poorer weight gain vs humanized or special preterm formulas.
9.SupplementDEX Database: Low birth weight — Protein quality in feeding low birth weight infants: a comparison of whey-predominant versus casein-predominant formulas1987
In 30 low-birth-weight infants, whey- vs casein-predominant formula at ~3.4 g/kg/day protein produced similar growth, nitrogen retention, and tolerance over feeding.
10.SupplementDEX Database: Low birth weight — Growth and adiposity of term infants fed whey-predominant or casein-predominant formulas or human milk1987
In 111 term infants, whey- or casein-predominant formula and breast milk led to similar growth and body composition over 16 weeks.
11.SupplementDEX Database: Low birth weight — A comparative trial of casein or whey-predominant formulae in healthy infants1986
In 100 healthy infants over 6 weeks, whey-predominant formula produced greater weight gain and head growth than casein-predominant Vitamilk.
12.SupplementDEX Database: Low birth weight — Comparative growth and biochemical response of very low birthweight infants fed own mother's milk, a premature infant formula, or one of two standard formulas1985
In VLBW infants, premature formula supported faster growth than standard or mother's milk alone; mother's milk groups had lower phosphate and higher alkaline phosphatase.
SupplementDEX Database · Athletic performance
11 references13.SupplementDEX Database: Athletic performance — Pre-sleep protein supplementation after an acute bout of evening resistance exercise does not improve next day performance or recovery in resistance trained men2022
In 18 resistance-trained men, 40 g pre-sleep casein after evening training did not improve next-day performance or recovery vs placebo over 2 days.
14.SupplementDEX Database: Athletic performance — Pre-Sleep Consumption of Casein and Whey Protein: Effects on Morning Metabolism and Resistance Exercise Performance in Active Women2018
In 9 active women, 48 g pre-sleep casein likely raised next-morning resting metabolic rate ~4% vs placebo; 24 g casein or whey did not clearly affect exercise volume.
15.SupplementDEX Database: Athletic performance — The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes2013
In 16 collegiate female athletes over 8 weeks, 24 g whey or casein pre/post training produced similar strength and body-composition changes with resistance exercise.
16.SupplementDEX Database: Athletic performance — The effects of six weeks of supplementation with multi-ingredient performance supplements and resistance training on anabolic hormones, body composition, strength, and power in resistance-trained men2012
In 24 resistance-trained men over 6 weeks, a multi-ingredient whey/casein supplement increased lean mass and strength markers vs placebo with periodized training.
17.SupplementDEX Database: Athletic performance — Physiological and physical effects of different milk protein supplements in elite soccer players2011
In 24 elite soccer players over 8 weeks, 1 g/kg/day whey, hydrolyzed whey, or casein with training maintained muscle mass; casein increased muscle mass slightly.
18.SupplementDEX Database: Athletic performance — Stimulation of muscle protein synthesis by whey and caseinate ingestion after resistance exercise in elderly individuals2011
In elderly adults after resistance exercise, whey and casein (before or after) produced similar muscle protein synthesis rates; timing did not significantly differ.
19.SupplementDEX Database: Athletic performance — Effect of protein-supplement timing on strength, power, and body-composition changes in resistance-trained men2009
In 33 resistance-trained men over 10 weeks, protein timing around workouts did not outperform morning/evening supplementation for strength, power, or body composition.
20.SupplementDEX Database: Athletic performance — Time-divided ingestion pattern of casein-based protein supplement stimulates an increase in fat-free body mass during resistance training in young untrained men2009
In 13 untrained men over 8 weeks, time-divided casein dosing increased fat-free mass more than pre-workout-only casein during resistance training.
21.SupplementDEX Database: Athletic performance — Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strength2006
In 19 untrained men over 10 weeks, 20 g whey/casein protein before and after training increased lean mass, strength, and anabolic markers vs dextrose placebo.
22.SupplementDEX Database: Athletic performance — The effect of whey isolate and resistance training on strength, body composition, and plasma glutamine2006
In 13 male bodybuilders over 10 weeks, whey isolate produced greater lean-mass gain (5.0 vs 0.8 kg) than casein with identical resistance training.
23.SupplementDEX Database: Athletic performance — Creatine-dextrose and protein-dextrose induce similar strength gains during training2001
In 19 untrained men over 8 weeks, post-exercise casein plus glucose matched creatine plus glucose for gains in strength, muscle area, and fat-free mass.
SupplementDEX Database · Diabetes
2 references24.SupplementDEX Database: Diabetes — Protein co-ingestion strongly increases postprandial insulin secretion in type 2 diabetes patients2014
In 60 men with type 2 diabetes, adding intact or hydrolyzed protein to carbohydrate doubled postprandial insulin secretion in nearly all participants.
25.SupplementDEX Database: Diabetes — Hydrolyzed casein decreases postprandial glucose concentrations in T2DM patients irrespective of leucine content2011
In type 2 diabetes patients, a hydrolyzed casein preload lowered 4-hour postprandial glucose ~4.7% vs placebo; unhydrolyzed casein had a smaller effect.
SupplementDEX Database · Blood sugar control
1 reference26.SupplementDEX Database: Blood sugar control — Effects of supplementation with milk protein on glycemic parameters: a GRADE-assessed systematic review and dose–response meta-analysis2023
A meta-analysis of 36 randomized controlled trials (1,851 participants) examining the effects of milk protein supplementation on glycemic outcomes. The review reported significant reductions in fasting blood glucose, fasting insulin, and HOMA-IR, while overall HbA1c did not change significantly; subgroup analyses showed HbA1c declines in participants with normal baseline BMI.
SupplementDEX Database · Obesity
9 references27.SupplementDEX Database: Obesity — Enhanced protein intake on maintaining muscle mass, strength, and physical function in adults with overweight/obesity: A systematic review and meta-analysis2024
A meta-analysis of 47 trials (3,218 adults) found higher protein during weight loss better preserved muscle mass and strength, especially above ~1.3 g/kg/day.
28.SupplementDEX Database: Obesity — Comparative effects of whey and casein proteins on satiety in overweight and obese individuals: a randomized controlled trial2014
In 70 overweight adults over 12 weeks, whey increased satiety and fullness before lunch vs casein or control; weight outcomes were not primary endpoints.
29.SupplementDEX Database: Obesity — Milk protein fractions moderately extend the duration of satiety compared with carbohydrates independently of their digestive kinetics in overweight subjects2014
In overweight adults, 30 g milk protein snacks modestly extended satiety vs maltodextrin; whey, casein, and mixed protein differed mainly in gastric emptying kinetics.
30.SupplementDEX Database: Obesity — Effects of hydrolysed casein, intact casein and intact whey protein on energy expenditure and appetite regulation: a randomised, controlled, cross-over study2014
A crossover study in overweight adults found hydrolyzed, intact casein, and whey did not differ in 24-hour energy expenditure or appetite despite different absorption rates.
31.SupplementDEX Database: Obesity — The effect of milk proteins on appetite regulation and diet-induced thermogenesis2012
In 17 overweight men, milk lowered subsequent lunch energy intake vs whey or casein shakes; casein increased postprandial fat oxidation vs whey.
32.SupplementDEX Database: Obesity — Skim milk, whey, and casein increase body weight and whey and casein increase the plasma C-peptide concentration in overweight adolescents2012
In 203 overweight adolescents over 12 weeks, skim milk, whey, or casein (35 g protein/L) increased BMI z-scores and C-peptide vs water control.
33.SupplementDEX Database: Obesity — Effects of whey protein isolate on body composition, lipids, insulin and glucose in overweight and obese individuals2010
In 70 overweight adults over 12 weeks, whey lowered triglycerides vs control and improved total/LDL cholesterol vs casein; body composition did not differ.
34.SupplementDEX Database: Obesity — The effect of a low-fat, high-protein or high-carbohydrate ad libitum diet on weight loss maintenance and metabolic risk factors2009
In 48 overweight adults after very-low-calorie loss, casein or whey protein during 12-week maintenance improved weight and fat retention vs maltodextrin control.
35.SupplementDEX Database: Obesity — Soy compared to casein meal replacement shakes with energy-restricted diets for obese women: randomized controlled trial2007
In 43 obese women over 16 weeks on equal energy-restricted diets, soy and casein meal-replacement shakes produced similar ~13% weight loss.