Supplement evidence

068 / 575Protein form

Casein protein

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The short answer

A slowly digested complete milk protein that supports protein intake and overnight amino-acid availability.

Evidence and scope: Supported for specific outcomes
This status does not grade the ingredient for every goal, outcome, or person.
Important limitation: Evidence supports a specific outcome, not a general wellness or longevity effect.
Before deciding: Key concern: Milk allergy and kidney disease require review; lactose content varies.

01 / PRACTICAL GUIDE

Dose, absorption, and combinations

These are indication-specific reference or studied ranges—not a personalized prescription. Start with the objective, then check the form, label, medicines, and health conditions.

Reference range by objective

Per-meal protein20–40 g per serving; 30–40 g before sleep is commonly studied

Reference or studied range—not a personalized prescription. The product label or a clinician may specify a different dose.

Dose source ↗

More is not automatically better. A clinician or product label may specify a different amount.

Absorption / solubilityFat/water classification is not the key factor

Fat/water solubility is not the useful decision point; preparation, fluid, timing, or strain identity matters more.

How it is commonly taken

Mix with adequate fluid; use within the daily protein target.

Do not combine casually

Milk allergy and kidney disease require review; lactose content varies.

Dose and use source ↗

Dose and use links lead to primary or official source material. Search links are discovery tools, not proof that every returned paper applies.

02 / EVIDENCE

What the research says

We keep supportive, mixed, negative, safety, and contextual findings together. The headline never replaces the underlying papers.

3research papers in this ledger

13unique primary studies represented

31unique participants represented

These are audited counts for this JIVANA collection, not search-result totals. Participants are counted once when multiple papers use the same cohort; review papers are not added again to participant totals.

Open the research timelineResearch timeline

Entries are ordered by publication year. A study period appears only when the source reports it.

2022

Does not support the tested claimPMID 35599912

Pre-sleep protein supplementation after evening resistance exercise does not improve next day performance or recovery

Pre-sleep casein did not improve next-day performance or recovery versus placebo. This acute null result does not address long-term hypertrophy, but it limits claims of an immediate overnight recovery advantage.

Published: 2022Duration: One night after a single exercise boutn=18 participants

Study design and methods

Design: Randomized, placebo-controlled acute trial
Population: 18 resistance-trained men
Intervention: Casein 40 g or noncaloric placebo 30 minutes before sleep after evening resistance exercise
Outcome: Next-day performance, soreness, muscle-damage markers, and perceived recovery

Funding or conflict note: The authors reported no conflicts of interest.

Open research record ↗

2021

Does not support the tested claimPMID 34070862

Pre-Sleep Casein Supplementation, Metabolism, and Appetite: A Systematic Review

Pre-sleep casein had limited to no effect on metabolism or next-day appetite and food intake. The evidence was limited and does not support fat-loss or appetite-control claims from timing casein before bed.

Published: 2021Duration: Varied across 11 randomized studies11 primary studies represented

Study design and methods

Design: Systematic review of 11 randomized controlled studies
Population: Healthy and overweight or obese adults
Intervention: Casein 24–48 g about 30 minutes before sleep versus control
Outcome: Energy expenditure, fat oxidation, appetite, and food intake

Funding or conflict note: The review reported no conflicts. No aggregate participant count was reported, so none is inferred.

Open research record ↗

2018

Mixed or qualifiedPMID 29764464 · NCT03352583

Daytime and nighttime casein supplements similarly increase muscle size and strength

Both groups gained muscle and strength, with no difference between daytime and pre-sleep casein. With only 13 completers and no no-protein group, the study supports meeting daily protein intake more than a special bedtime window.

Published: 2018Duration: 10 weeksn=13 participants

Study design and methods

Design: Randomized, double-blind timing comparison during resistance training
Population: 13 men completing a controlled high-protein diet and training program
Intervention: Casein 35 g/day earlier in the day or immediately before sleep; daily protein was 1.8 g/kg
Outcome: Lean soft tissue, muscle thickness, leg-press and bench-press strength

Funding or conflict note: Dymatize and FrieslandCampina funded the study; authors reported employment, consulting, or executive roles with those or other sports-nutrition companies.

Open research record ↗

Unscreened discovery appendix—not evidence13 candidate publicationsSearch run: Aug 21, 2026

Complete for the displayed PubMed query at the search timestamp—not for all databases or every possible synonym. Candidates can be irrelevant, duplicate the same study, or report negative findings. They are never summed as evidence or participants until screened.

03 / SOURCES

Start with the source material

Official evidence overviewPubMed bounded human-evidence search Live PubMed discovery searchNational Library of Medicine

The live search is for discovery only. Search-result counts change and are not included in the audited totals above.

Recent PubMed discovery recordsDirect links to the first 12 records returned by the reproducible search. These are discovery candidates—not reviewed summaries or a count of supportive findings.

04 / EXPERT CONTEXT

Expert context—not evidence

Expert positions are dated context—not scientific evidence. They never raise the evidence status or become consensus by repetition.

No direct, source-verified endorsement is currently recorded. Research authorship or discussion alone is not treated as endorsement.