GLYCINE: The Cheapest Anti-Aging Supplement That Actually Works

Glycine
What if feeling older or slower or more
tired wasn’t about age, but about a
shortage of one small molecule that your
body quietly depends on every second of
the day? Well, that molecule is glycine.
And it sounds simple, but glycine sits
at the center of how your body sleeps
and recovers and even defends itself
from oxidative stress. And most people
overlook it, but glycine is one of the
most important foundational pieces of a
process called glutathione synthesis.
Because glutathione is that master
antioxidant that protects your body from
cellular damage. And glutathione is
essential for almost all bodily
functions. So before you go out and buy
a supplement, watch this through because
I’ll go over what science actually says
about glycine and how it can affect your
sleep and your metabolism and even
aging. And I also want to talk about
when does it make sense to combine
glycine with another amino acid called
knack or another name for that is an
acetylcysteine. and I’ll go over what
human studies show about the glyide
combination because the data is a lot
stronger than most people realize. And
in the end, I want to go over proper
dosing for glycine and I want to go over
glycine’s potential side effects. And
just like with any of my videos, even
though I’m a physician, I’m not your
physician. So, please talk to your
doctor before you make any changes to
your supplements as this video is
educational only and not medical advice.
What Glycine Does
So, let’s start with what glycine
actually does. It’s the smallest amino
acid in your body, but it’s involved in
almost every biological process like
building proteins and forming collagen.
Glycine also supports your liver and it
regulates neurotransmitters. And this is
very important. Glycine also plays a
very critical role in producing
glutathione, which is your body’s main
detox and antioxidant defense system.
Glutathione is what keeps your cells
alive under stress. Every time you
produce energy, you generate reactive
oxygen species, which are these tiny
chemical sparks that can basically
damage your DNA and it can hurt your
cell membranes. So, this is where your
glutathione comes in. It neutralizes
those damaging sparks, those reactive
oxygen species, and it recycles other
antioxidants like your vitamin C and
your vitamin E. And glutathione also
protects your mitochondria from
oxidative damage. So to fully understand
Glutathione Explained
this process, it really helps to
visualize how glutathione is formed. It
is composed of three amino acids.
Glutamate, cyine, and glycine. And
here’s the catch. Glycine and cyine are
often the rate limiting factors in this
process. Meaning if either of them is
low, glutathione production slows down.
And this is why glycine is so
interesting. I used to think of it as
just something that you take for sleep.
But glycine is a major metabolic
regulator that may also have anti-aging
Sleep Benefits?
benefits. So, let’s start with sleep
because this is where the evidence is
the strongest. We have research in both
animals and humans that suggest that
glycine supplementation before bedtime
can enhance subjective and objective
sleep quality. There’s also data that
shows that glycine can improve several
sleep parameters like improve nextday
cognitive performance and alertness. And
glycine can reduce sleep onset latency.
Basically, it helps you fall asleep
faster. And this is how it works.
Glycine activates your NMDA receptors in
your superismatic nucleus, which then
leads to peripheral vasoddilation. So,
what does that mean? Well, your
supercharismatic nucleus is just a
cluster of neurons in the part of the
brain called hypothalamus. And this is
basically your internal clock that
regulates your circadian rhythm. This is
the part of the brain that receives
light signal from the retina. And it
uses this signal to maintain your body’s
24-hour sleep and wake cycle. So glycine
activates the crucial part of the brain
in a way that leads to relaxation of
your blood vessels, which then causes
more heat to leave your body and that in
turn naturally cools your core
temperature. And when your body
temperature drops, this is when your
brain gets the signal that it’s time for
sleep. But there’s another amazing way
glycine can help you with your sleep.
Glycine quiets your wake up neurons that
use a chemical called arexin. So those
neurons help keep you awake during the
day, but at night we need to dial those
down and glycine does just that. So
glycine can help you relax and have
restful sleep throughout the night.
Glycine also helps balance out your
serotonin and other neurotransmitters
that help with sleep regulation. And on
top of that, this is very important,
glycine helps your muscles fully relax
during REM sleep, which is absolutely
essential because that’s what keeps your
body still while you’re having active
dreams. So, all of those benefits
combined is what keeps your sleep
restful and lets your body repair itself
Metabolic / Anti-Inflammatory Benefits?
through the night. But glycine’s effects
go far beyond sleep. It has significant
metabolic and anti-inflammatory actions.
There was a 2022 review study that
showed that glycine may have a role in
improving different components of
metabolic syndrome, which is that
constellation of insulin resistance and
obesity and high cholesterol and high
blood pressure. And this totally makes
sense because glycine levels are often
lower in individuals with metabolic
syndrome or obesity or insulin
resistance. So even though glycine is
generally viewed as a non-essential
amino acid because your body can
synthesize it to an extent, there’s
studies to suggest that it may be
conditionally essential in the presence
of metabolic disorders like diabetes or
fatty liver disease because then your
body uses much more glycine and it may
not be able to generate it in sufficient
amounts. And there’s multiple studies
that show glycine’s anti-inflammatory
effects. But this is where we also need
GlyNAC
to pause and discuss another important
component of glycine supplementation and
that is an acetylcysteine or knack. Some
people prefer to take glycine by itself
but some say you should not take glycine
unless you take it as glyc or glycine
plus an acetylcyine. So what’s the big
deal? Well, if you recall, the reason
glycine is so important is because it’s
one of the three amino acids your body
needs to make glutathione, which is an
incredibly important antioxidant that
basically protects every cell in your
body from oxidative stress or damage.
The other two amino acids are glutamate
and cyine. So, when you take glycine
alone, your body still depends on cyine
to complete that glutathione synthesis.
But cyine can also be that rate limiting
step because it’s so unstable. Cyine is
easily oxidized and it’s usually in
short supply, especially if you’re under
stress or if you have a lot of
inflammation or illness. So during the
times when you need it the most. So the
argument is even if you flood your
system with glycine, you cannot build
enough glutathione without more cyine.
So it’s like trying to build a house
with extra bricks but no cement. And
this is where knack or anetylcysteine
comes in. Knack delivers cyine in a
stable form that your cells can actually
use. And once your cyine levels are
depleted, then that’s when glycine can
finally become that critical finishing
piece. So without glycine, you can’t
finish the molecule. But without cyine,
you can’t even start the process. And
this glo combo has been studied in both
animals and humans. There was a 16-week
randomized control trial in older adults
that showed that gleac supplementation
improve multiple aging hallmarks like
mitochondrial dysfunction and oxidative
stress. But what was even more amazing
is that the group that took Gleneak
showed gains in muscle strength and
faster gate speed and GLEAC help improve
cognitive performance. These are all
important markers of healthy aging and
increasing health span. And there was a
small human study that showed that GLEAC
may improve insulin resistance in
patients with type 2 diabetes. But one
thing to emphasize, all of these studies
were very small and short in duration.
So, the data on this is just not as
robust or as strong as we’d like to see.
Glycine vs GlyNAC
Okay. So, how do we decide whether you
should take glycine or glyc? Well, the
way I look at it is if you’re young and
healthy, your glutathione system is
likely already working just fine. And in
that case, glycine alone will probably
do the job, especially if we’re just
taking it for sleep. But if you have any
metabolic issues like insulin resistance
which encompasses things like diabetes
and pre-diabetes and PCOS or if you have
fatty liver or high blood pressure or
cholesterol issues or if you have
chronic inflammation or an autoimmune
condition well then in that case gleac
theoretically would probably be better
as you’ll may need that additional bump
of cyine to complete that glutathione
Dosing
synthesis. Now, when it comes to dosing,
the most studied dose for glycine alone
was 3 g, taken about 30 to 60 minutes
before sleep. Glycine dissolves pretty
easily in water, and it tastes pretty
sweet, and it’s usually very well
tolerated. Now, some people take mega
doses of glycine, so they take doses
much bigger than 3 g. And we do have
some studies that looked at higher
dosing. So, there’s studies in adults
with schizophrenia where glycine was
administered at 800 mg per kilogram per
day. And the mean daily dose was about
61 g with a range from 40 to 90 g. Now
looking at the literature, glycine at 3
g per day is generally well tolerated
with only mild side effects being slight
sedation. Um but once you get to higher
doses like 800 mg per kilogram per day
in the schizophrenia studies looks like
that dose was still pretty well
tolerated with no major safety issues.
But these were small short-term studies.
So, I’ll be cautious trying to
extrapolate those results to broader
populations. There are cases where high
doses of glycine led to neurobbehavioral
changes and sensory overload. And in
animal models, there may be a potential
concern for cardiovascular and
neurological toxicity. So, as a general
rule, I do not recommend mega dosing on
glycine, at least until we get more
human data on safety. And when it comes
to GLAC, the recommended dose in
published human studies was typically
100 mg per kilogram of glycine and 100
milligs per kilogram of anosetylcysteine
per day. So for a 70 kg person, which is
about 154 lbs, that works out to about 7
g of each per day split into two doses.
Now most people start much lower at
around 3 g per day and then increase it
gradually. Knack by itself can cause
gastrointestinal side effects like
nausea and diarrhea. And you have to be
careful if you have history of asthma or
allergies. But in general, it’s pretty
well tolerated even at higher doses.