Fuel before shut-eye might boon your gains but it may not matter as much as you think.
Last updated on June 17th, 2025
Are you limiting muscle gains by skipping protein before bed? Does casein protein offer any advantages over whey?
“I am skeptical that there’s anything special about casein,” House of Hypertrophy (HOH) said. In June 2025, HoH compiled data on protein before sleep, concluding that “It seems slow and fast proteins are probably similar for increasing lean mass…including plant-based proteins,” though not statistically significant enough to be better than total protein consumption throughout the day. (1)(2)(3)
Consuming enough protein per day is likely more critical than protein timing.
The Latest Research on Bedtime Protein
A 2021 systematic review found that 20 to 40 grams of casein protein, about 30 minutes before sleep, stimulates overnight muscle protein synthesis (MPS) (i.e., muscle building) in men. (4) It boosted muscle and strength in the younger age group after 12 weeks of training.
This data may be misleading, though. Most studies used casein due to its slow digestion rate, which is believed to sustain overnight muscle feeding. Is this just a marketing ploy?
A 2023 study compared 45 grams of casein, 45 grams of whey, and a non-caloric placebo before bed after evening exercise. Whey produced a higher peak in blood amino acids; casein prolonged the amino acid elevation. However, MPS rates were not significantly different. (5)
Is Total Protein Intake the Key?
In a 12-week study in the 2021 review, one group consumed 1.9 grams of protein per kilogram of bodyweight per day, another consumed 1.3 grams at the same rate, and a third consumed a placebo. Gains were not solely attributed to protein timing. (6)
To address this, three controlled studies equated total protein intake:
- A study of 26 trained subjects compared 54 grams of casein before bed or in the morning over eight weeks. Fat-free gains were numerically higher for pre-sleep (1.2 kg vs. 0.4 kg), but not statistically significant. (7)
- Another study with recreational athletes training for 10 weeks found no differences in muscle or strength gains between groups consuming 35 grams of casein before bed or earlier in the day. (8)
- The third study involved 42 untrained subjects divided into pre-sleep and morning whey protein groups. While muscle gains slightly favored the pre-sleep group, strength gains favored the morning group. No differences reached statistical significance. (9)
“Unlike the data that does not control total daily protein intake, the research that controls total protein daily intake finds no discernible differences in muscle and strength gains between pre-sleep protein and protein consumed at another time,” HoH explained.
What About Sleep Quality?
The referenced studies found no adverse impacts of bedtime protein intake on sleep quality, though it varies between individuals. A bigger meal, including carbs and fats, would more likely contribute to sleep disturbance. (10)(11)
Should You Ingest Protein Before Sleep?
The literature is clear that total daily protein intake is the most important thing.
—House of Hypertrophy
Pre-sleep protein may have marginal benefits, especially for those who don’t consume enough protein. To maximize muscle growth, aiming for between 1.6-2.2 grams of protein per kilogram of bodyweight per day is recommended, which is likely far more impactful than nutrient timing. (12)
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References
- Fabre M, Hausswirth C, Tiollier E, Molle O, Louis J, Durguerian A, Neveux N, Bigard X. Effects of Postexercise Protein Intake on Muscle Mass and Strength During Resistance Training: Is There an Optimal Ratio Between Fast and Slow Proteins? Int J Sport Nutr Exerc Metab. 2017 Oct;27(5):448-457. doi: 10.1123/ijsnem.2016-0333. Epub 2017 Apr 19. PMID: 28422532.
- Wilborn CD, Taylor LW, Outlaw J, Williams L, Campbell B, Foster CA, Smith-Ryan A, Urbina S, Hayward S. The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes. J Sports Sci Med. 2013 Mar 1;12(1):74-9. PMID: 24149728; PMCID: PMC3761774.
- Hevia-Larraín V, Gualano B, Longobardi I, Gil S, Fernandes AL, Costa LAR, Pereira RMR, Artioli GG, Phillips SM, Roschel H. High-Protein Plant-Based Diet Versus a Protein-Matched Omnivorous Diet to Support Resistance Training Adaptations: A Comparison Between Habitual Vegans and Omnivores. Sports Med. 2021 Jun;51(6):1317-1330. doi: 10.1007/s40279-021-01434-9. Epub 2021 Feb 18. PMID: 33599941.
- Reis CEG, Loureiro LMR, Roschel H, da Costa THM. Effects of pre-sleep protein consumption on muscle-related outcomes – A systematic review. J Sci Med Sport. 2021 Feb;24(2):177-182. doi: 10.1016/j.jsams.2020.07.016. Epub 2020 Aug 7. PMID: 32811763.
- Trommelen J, van Lieshout GAA, Pabla P, Nyakayiru J, Hendriks FK, Senden JM, Goessens JPB, van Kranenburg JMX, Gijsen AP, Verdijk LB, de Groot LCPGM, van Loon LJC. Pre-sleep Protein Ingestion Increases Mitochondrial Protein Synthesis Rates During Overnight Recovery from Endurance Exercise: A Randomized Controlled Trial. Sports Med. 2023 Jul;53(7):1445-1455. doi: 10.1007/s40279-023-01822-3. Epub 2023 Mar 1. PMID: 36857005; PMCID: PMC10289916.
- Snijders T, Res PT, Smeets JS, van Vliet S, van Kranenburg J, Maase K, Kies AK, Verdijk LB, van Loon LJ. Protein Ingestion before Sleep Increases Muscle Mass and Strength Gains during Prolonged Resistance-Type Exercise Training in Healthy Young Men. J Nutr. 2015 Jun;145(6):1178-84. doi: 10.3945/jn.114.208371. Epub 2015 Apr 29. PMID: 25926415.
- Antonio J, Ellerbroek A, Peacock C, Silver T. Casein Protein Supplementation in Trained Men and Women: Morning versus Evening. Int J Exerc Sci. 2017 May 1;10(3):479-486. doi: 10.70252/QWHA8703. PMID: 28515842; PMCID: PMC5421981.
- Joy JM, Vogel RM, Shane Broughton K, Kudla U, Kerr NY, Davison JM, Wildman REC, DiMarco NM. Daytime and nighttime casein supplements similarly increase muscle size and strength in response to resistance training earlier in the day: a preliminary investigation. J Int Soc Sports Nutr. 2018 May 15;15(1):24. doi: 10.1186/s12970-018-0228-9. PMID: 29764464; PMCID: PMC5952515.
- Chen Y, Liang Y, Guo H, Meng K, Qiu J, Benardot D. Muscle-Related Effect of Whey Protein and Vitamin D3 Supplementation Provided before or after Bedtime in Males Undergoing Resistance Training. Nutrients. 2022 May 30;14(11):2289. doi: 10.3390/nu14112289. PMID: 35684089; PMCID: PMC9183069.
- Holwerda AM, Kouw IW, Trommelen J, Halson SL, Wodzig WK, Verdijk LB, van Loon LJ. Physical Activity Performed in the Evening Increases the Overnight Muscle Protein Synthetic Response to Presleep Protein Ingestion in Older Men. J Nutr. 2016 Jul;146(7):1307-14. doi: 10.3945/jn.116.230086. Epub 2016 Jun 8. PMID: 27281811.
- Trommelen J, Kouw IWK, Holwerda AM, Snijders T, Halson SL, Rollo I, Verdijk LB, van Loon LJC. Presleep dietary protein-derived amino acids are incorporated in myofibrillar protein during postexercise overnight recovery. Am J Physiol Endocrinol Metab. 2018 May 1;314(5):E457-E467. doi: 10.1152/ajpendo.00273.2016. Epub 2017 May 23. PMID: 28536184.
- Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM. 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. Br J Sports Med. 2018 Mar;52(6):376-384. doi: 10.1136/bjsports-2017-097608. Epub 2017 Jul 11. Erratum in: Br J Sports Med. 2020 Oct;54(19):e7. doi: 10.1136/bjsports-2017-097608corr1. PMID: 28698222; PMCID: PMC5867436.
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