Sleep optimization has become an obsession for many, with people popping dozens of supplements, taping their mouths shut, and even taking nighttime cold plunges.
But according to fitness expert Thomas DeLauer, most are missing the point entirely.
In a recent video, DeLauer explained that sleep struggles aren’t usually about lacking sedatives—they’re about instability in the nervous system and circadian clock.
Two amino acids, L-serine and glycine, might be the answer to restoring deep, restorative sleep without the supplement graveyard on your nightstand.
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Why Your Circadian Rhythm Is Drifting (And How L-Serine Stops It)
Most people assume sleep timing is behavioral—go to bed earlier, dim lights, shut down screens. While those habits matter, your biological clock can actually drift.
Stress, irregular meals, and inflammation all push your circadian rhythm later. That’s where L-serine comes in.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
A study published in the Journal of Physiological Anthropology tested healthy university students who took either 3 grams of L-serine or a placebo 30 minutes before bed for two weeks. Researchers measured DLMO—dim light melatonin onset—the gold standard marker for circadian timing.
The placebo group’s sleep schedule drifted later over the study period. The L-serine group stayed stable.
L-serine prevented circadian delay by stabilizing internal clock function and maintaining consistent melatonin timing. When your rhythm drifts, everything suffers: falling asleep becomes harder, you feel tired but wired, and daytime energy becomes unpredictable.
L-Serine Improves Sleep Initiation and Maintenance
Two randomized, double-blind crossover studies published in Springer Plus examined L-serine’s effects on people with poor sleep quality. Researchers used subjective sleep ratings, questionnaires, and actigraphy—wearable devices tracking sleep-wake cycles.
Results showed L-serine improved both sleep initiation and maintenance. People fell asleep easier, stayed asleep more consistently, and woke feeling more satisfied.
L-serine doesn’t just help timing—it supports sleep continuity, preventing those frustrating middle-of-the-night awakenings that leave you staring at the ceiling.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
How Glycine Transforms Sleep Quality and Depth
While L-serine stabilizes timing, glycine enhances depth and quality. Glycine plays dual roles as both neurotransmitter and protein building block.
For sleep, its neurotransmitter function steals the spotlight.
Research published in Sleep and Biological Rhythms gave 3 grams of glycine to people with poor sleep, measuring outcomes through polysomnography—the comprehensive lab sleep test.
Results were striking across subjective and objective measures.
- Subjectively: Participants felt they slept better and woke more refreshed
- Objectively: They fell asleep faster, entered deep sleep sooner, and improved sleep efficiency
- Daytime benefits: Lower daytime sleepiness and better memory recognition performance
Glycine didn’t just help people fall asleep—it helped them sleep in ways that supported next-day functioning.
The Temperature Connection
A study in Neuropsychopharmacology revealed glycine lowers core body temperature by activating NMDA receptors in the suprachiasmatic nucleus (SCN)—the brain’s master circadian clock.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Lowering body temperature is natural during sleep onset. Glycine increases heat loss through skin and triggers sleep initiation signals.
When researchers blocked those NMDA receptors, glycine stopped working—proof the mechanism is real and specific.
Glycine Reduces Nighttime Bathroom Trips
For millions struggling with nighttime urination, glycine offers unexpected relief.
A study in the Journal of Complementary and Integrative Medicine tested glycine in people with overactive bladders. After four weeks, nighttime urination, urinary urgency, and sleep disruptions all decreased significantly.
Glycine turns down the wake up because I have to go pee signal. Doesn’t make you wet the bed. You just don’t have to pee.
Waking multiple times to urinate breaks sleep architecture and resets whatever stage you’re in. Glycine acts as an inhibitory neurotransmitter in the spinal cord, calming the nocturnal reflex and reducing that urgent feeling.
The Creatine-Sleep Connection Nobody Talks About
Here’s where things get fascinating. Glycine serves as a precursor to creatine, deeply tied to brain energy homeostasis during deep sleep.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Research in the Journal of Sleep Research found creatine supplementation reduced total sleep time and sleep pressure in rats. Why? Because the brain had more phosphocreatine—a better backup energy supply.
Your brain sleeps partly to restore energy. When energy systems are unstable, your brain wakes you up sooner.
Glycine leads to creatine. Creatine leads to stable brain energy. Stable brain energy leads to deeper, more continuous sleep.
This doesn’t mean glycine replaces sleep, but it helps prevent your brain from panicking when ATP levels drop during rest.
Glycine Blunts Stress and Emotional Arousal at Night
Glycine exerts calming effects on the nervous system by reducing excitatory signaling.
A 2024 review in Sleep Medicine Reviews and 2017 research in Neuroscience emphasized that emotional reactivity—especially negative emotions—delays sleep onset and disrupts REM patterns.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Worries about work, relationships, or what others think can keep you awake. How well you regulate emotion determines how severely stress impacts sleep.
A study in Aquaculture (yes, in fish, but mechanistically valuable) showed glycine supplementation dramatically reduced cortisol spikes in response to stress.
I don’t know, it seems like fish are always stressed out. So hopefully it helps their life in general because they’re always like freaking out.
As an inhibitory neurotransmitter, glycine likely helps humans similarly—calming the nervous system, reducing emotional arousal, and suppressing nighttime cortisol bursts.
Glycine helps your brain settle so you can fall asleep and stay asleep.
How to Use L-Serine and Glycine Together
Think of L-serine as the clock stabilizer and glycine as the sleep quality builder. Together, they support root systems: timing, temperature, energy stability, and emotional regulation.
If you want to experiment, here’s what research suggests:
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
L-Serine Dosing
Studies used approximately 3 grams about 30 minutes before bed. This appears most helpful for people whose sleep feels shifted later or inconsistent—circadian rhythm stabilization is the key benefit.
Glycine Dosing
Research also used 3 grams before bed. Glycine helps with sleep quality, deeper sleep stages, faster onset, and fewer awakenings.
Stacking Both
If combining them, start conservatively: 2-3 grams of each, taken together 30 minutes before bed.
Don’t obsess over tracking sleep. Pay attention to how you feel the next morning—clarity, energy, and ease of falling asleep are better markers than wearable data.
Special Consideration for Nocturia
If nighttime bathroom trips are your primary issue, cut fluid intake earlier and consider taking glycine an hour before bed rather than 30 minutes.
Glycine taken earlier in the evening can still help reduce nighttime urination while allowing time for any fluids to pass through your system.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
The bottom line? Stop chasing symptoms with endless supplements. Address the deeper wiring—circadian stability, nervous system balance, and brain energy—with targeted amino acid support that actually works with your biology.
