Sleep Stack

Nighttime Protein: The Overnight Recovery Window Explained

April 29, 2026 · Jordan Selden

Half your recovery happens while you sleep.

Not in the gym. Not at lunch. Not in the post-workout window everyone optimizes around.

The 8 hours between dinner and breakfast are when your body actually rebuilds — synthesizing muscle protein, releasing growth hormone, repairing tendons and tissue, consolidating motor learning. It's the longest single recovery window in your day. And for most lifters, it's the worst-fed.

That's the gap nighttime protein is built for.

What is nighttime protein?

Nighttime protein is a category, not a flavor. It's protein engineered specifically for the overnight recovery window — meaning the formulation, the digestion rate, the dose, and the surrounding co-factors are all built around what your body is actually doing during sleep.

The defining features:

Slow-digesting protein source — typically micellar casein. Whey hits your bloodstream in 30 minutes and is gone within 90. Casein digests over 6 to 8 hours, matching the length of a full sleep cycle. (Res et al., 2012)
Sleep-supportive co-factors — magnesium, glycine, L-theanine, apigenin. These aren't added to make the product feel premium. They're added because the same hours your muscles are rebuilding are the hours your nervous system is consolidating, your hormones are cycling, and your body temperature is dropping. Recovery is systemic, not muscular.
No stimulants, no melatonin — nighttime protein doesn't sedate you, and it doesn't override your circadian clock. It feeds the system that's already trying to rebuild.

That's the spec. Anything that doesn't hit all three isn't nighttime protein. It's just protein you happen to be drinking at night.

Why daytime protein doesn't reach the night

Whey protein is the gold standard for one specific job: spiking blood amino acids fast after a workout, when muscle protein synthesis (MPS) machinery is sensitive and ready. For that job, whey is essentially perfect.

But the half-life that makes it perfect for post-workout makes it useless for sleep. Whey concentrate digests in 30 to 60 minutes. Whey isolate is even faster. By the time you're brushing your teeth at 9:30, your post-dinner whey shake has finished its job. The remaining 8 hours of recovery happen in a fasted state.

This is the part most people miss. The "30-minute anabolic window" everyone trains around is real — but it's followed by a much longer window during sleep where MPS continues, and where your inputs determine the rebuild.

A 2016 review out of Maastricht (Trommelen & van Loon, 2016) put this directly: pre-sleep protein ingestion at 40g elevates overnight muscle protein synthesis rates by roughly 22% versus no protein, with the bulk of the rebuild happening in the second half of the night — exactly the window whey can't reach.

The sleep stack — beyond protein

If your only goal were "more amino acids overnight," you could just drink casein. But sleep is where the rest of the recovery system works too — and it works better when fed.

The four co-factors that round out a complete nighttime protein:

Glycine. Glycine drops your core body temperature roughly 0.3°C. That's the same thermal trigger your brain uses to initiate deep sleep. A 2007 study (Yamadera et al.) found 3 grams of glycine before bed improved subjective sleep quality and decreased sleep latency. Bonus: glycine is one of the building blocks of collagen, so it doubles as connective-tissue support.

Magnesium bisglycinate. Magnesium oxide — the form in most multivitamins — has a bioavailability around 4%. Magnesium bisglycinate, magnesium bound to two glycine molecules, absorbs around 80% and won't wreck your gut. It supports parasympathetic nervous system activation, the "rest and digest" mode. (Abbasi et al., 2012)

L-theanine. The focus compound in matcha is also a sleep compound at night. Same molecule, different context: it tells your brain to release alpha waves and let go of background mental noise. (Lyon et al., 2011) Pairs naturally with the slowness of casein.

Apigenin. The actual sleep compound in chamomile. Studies use 50 mg. A cup of chamomile tea has about 0.4 mg. If you're drinking chamomile for sleep, you're drinking it for the ritual. Apigenin at the studied dose modulates GABA-A receptors — calming without sedation, which is why it doesn't leave you groggy.

These four aren't a vitamin shotgun. They're a stack — mutually reinforcing, dosed at study levels, and chosen specifically because they support the same window casein is rebuilding.

Why nighttime protein is a category, not a SKU

Most "nighttime protein" products on the shelf today are casein with a sleep claim slapped on the label. That's not the category — that's just casein.

A real nighttime protein category looks like:

A defined window (the 8 hours of overnight recovery)
A mechanism (slow-digest protein + sleep co-factors)
A dose floor (the protein and the co-factors at study-level amounts, not pixie-dust label claims)
A use case (consumed as the last thing you ingest, replacing both your evening protein shake and your separate sleep supplements)

Once you spec the category that way, you can compare products inside it. You can ask: does this product hit study-level magnesium? Is the casein micellar or hydrolyzed? Is the apigenin dosed at 50 mg or 5 mg? Is the dose disclosed at all, or hidden behind a "proprietary blend"?

Those are the questions a real category invites. And those are the questions Moon Milk was built to win.

How Moon Milk fits

Moon Milk is 20 grams of micellar casein per serving — the slow-digest, time-release form, not the fast-acting casein hydrolysate. Plus the full sleep stack: 200 mg magnesium bisglycinate, 3 g glycine, 200 mg L-theanine, 50 mg apigenin. No melatonin. No added sugar. No caffeine.

We dose every co-factor at the study level. We disclose every milligram on the label. And we make every bag in a shared kitchen in Austin, blended by the founder, in 500-bag runs.

The category is small today. So is the awareness. But the recovery window is permanent — it happens every night, in every body, for every athlete and lifter and shift worker and parent. Eventually, the obvious thing wins.

Frequently asked

Will nighttime protein make me gain fat?
No. The 2015 Snijders study found pre-sleep casein for 12 weeks of resistance training increased lean mass and strength versus a placebo without increasing fat mass. Total daily calories matter — the timing within them does not cause fat gain.

Should I drink it instead of dinner?
No. It's a final input — drink it 30 to 60 minutes before bed, after dinner. The point is to keep amino acids elevated through the overnight fast, not to replace a meal.

How is this different from a regular casein shake?
Casein is one ingredient. Nighttime protein is a system: slow-digest protein plus sleep-supportive co-factors at study-level doses. Casein alone gives you the protein synthesis bump. The co-factors give you the deep sleep, recovery latency, and nervous-system reset that determine the quality of the rebuild.

Why no melatonin?
Melatonin is a hormone, not a nutrient. Daily exogenous melatonin can suppress your body's own production. We use ingredients that support your body's existing systems instead of overriding them. Read more: Why Moon Milk Has Zero Melatonin.

What time should I drink nighttime protein?
30 to 60 minutes before bed. Long enough for the magnesium and glycine to start working on body temperature and parasympathetic activation. Short enough that the casein protein is digesting through your sleep window.