Research Studies Involving the Ingredients
- HgH Amino Acids Blend

These Research Studies on the Ingredients
Used in the Formulations of GHR Platinum
Prove that the GHR Platinum HGH Product Really Works

- HGH AMINO ACIDS BLEND - 

Dr. LE Dorman, MD - Growth Hormone / Amino Acid Blend
Author of "The Methusaleh Factor"

As we age, our body stops producing an adequate supply of HGH amino acids. Out of the 191 amino acids in the Growth Hormone chain, GHR PLATINUM replenishes the body with the needed blend of Stacked HGH Amino Acids in the Right Ratio and Molecular Weight that helps Stimulate and Restore the Release of your body’s own natural Growth Hormone. Many substances stimulate the release of Growth Hormone from the pituitary gland. Amino acids ( from HGH chain ), drugs and exercise are among the provocateurs." ( Page 35 )

- L-ARGININE - 

The Amino Acid - ARGININE has two main purposes in how it works:

1. It is a precursor to making other substances in the body. The first is that it works by converting into the compound Nitric Oxide. This substance is involved in various metabolic activities in the body. These include the regulation of the flow of blood, cellular activities of the Mitochondria to create energy, and sending signals of communications between the cells.

One of the ways that Nitric Oxide works, is by dilating and relaxing blood vessels. So it functions as a Vasodilator. This improves the flow and circulation of the blood throughout the entire body, which enables more nutrients and oxygen in the blood to supply the organs, muscles, tissues and cells. This aspect also helps to reduce high blood pressure. As a result of these actions, ARGININE helps promote a healthy heart function. Therefore, it can be useful in treating such conditions as Hypertension, Angina, Circulatory System Diseases and Erectile Dysfunction ( ED ).

At the same time, Nitric Oxide also aids the body in removing waste products from both the Liver and the muscles. In particular, this includes the metabolic waste substances Lactate and Ammonia. This then helps the muscles, and your entire body, to recover quicker from physical exercise and strenuous workouts.

2. ARGININE helps the body to create proteins. At the same time, it also helps support a good Immune System. Finally, it is also used in the metabolism of Sugars. So it might help improve Insulin Sensitivity. There are some research studies which indicate that it may thus help people suffering from Type 2 Diabetes.

One of the symptoms of the aging process is that our bodies might not produce enough Arginine. Or our bodies do NOT produce it very well. So, it often is necessary for older people to consume more Arginine by using supplements.

In the last thirty years, there have been lots of research studies, which show that increasing the amount of the Amino Acids of ARGININE and LYSINE we obtain, will help raise the production and then release of Growth Hormone ( GH ) in the body. Both of these amino acids are included in the GHR PLATINUM Hgh Boosters. Here are just a few of these studies which conclude that ARGININE is a Growth Hormone Releaser ( GHR ).

Growth Hormone, Arginine and Exercise

https://pubmed.ncbi.nlm.nih.gov/18090659/

"Most studies using oral ARGININE have shown that ARGININE alone increases the resting Growth Hormone levels at least 100%"

Growth Hormone Responses to Varying Doses of Oral Arginine

https://pubmed.ncbi.nlm.nih.gov/15809017/

"5 and 9 grams of oral ARGININE caused a significant ( Growth Hormone ) GH response"

Increased Human Growth Hormone Following Oral Consumption
of an Amino Acid Supplement: Results of a Randomized,
Placebo-Controlled, Double-Blind, crossover study in Healthy Ssubjects

https://pmc.ncbi.nlm.nih.gov/articles/PMC6732240/

"It is well established that intravenous (IV) administration of some amino acids results in significantly increased HgH secretion. Such studies prompted testing of oral amino acids supplements ( primarily ARGININE, Lysine & Orthinine )
to stimulate HgH secretion."

A Study of Growth Hormone Release in Man After Oral Administration of Amino Acids

https://pubmed.ncbi.nlm.nih.gov/6790230/

"A study was carried out in [ fifteen ] 15 male volunteers to evaluate qualitatively the secretion of growth factors following stimulation by oral amino acids. The results showed that oral administration of a combination of two amino acids ( 1,200 mg 1-Lysine plus 1,200 mg 1-ARGININE ) provoked a release of Pituitary Somatotropin { related to GH } and Insulin."

"This phenomenon was reproducible and the growth hormone secreted in response to this stimulation had biological activity ( as demonstrated by a radioreceptor assay and somatomedin induction ). The effect appeared to be specific to the combination of the two amino acids."

Acute Effect of Amino Acid Ingestion and Resistance Exercise
on Plasma Growth Hormone Concentration in Young Men

https://pubmed.ncbi.nlm.nih.gov/9063764/

Sixteen men completed four trials at random as follows:

( Trial A ) Performance of a single bout of resistance exercise preceded by placebo ingestion ( Vitamin C );

( Trial B ) Ingestion of 1,500 mg L-ARGININE and 1,500 mg L-Lysine, immediately followed by exercise as in Trial A;

( Trial C ) Ingestion of amino acids as in Trial B and no exercise;

( Trial D ) Placebo ingestion and no exercise.

Growth Hormone ( GH ) concentrations were higher at 30, 60, and 90 min during the ( two ) exercise trials ( A and B ) compared with the resting trials ( C and D ). No differences were noted in Growth Hormone [ GH ] between the exercise trials.

It was concluded that ingestion of 1,500 mg ARGININE and 1,500 mg Lysine immediately before resistance exercise does not alter exercise-induced changes in Growth Hormone [ GH ] in young men.

However, when the same amino acid mixture ( 1,500 mg ARGININE and 1,500 mg Lysine ) is ingested under basal conditions, the acute secretion ( release ) of [ Growth Hormone ] GH is increased.

- L-LYSINE - 

L-LYSINE is one of the eight ( 8 ) "Essential" Amino Acids. Thiese are the ones which our bodies can NOT make. So we have to consume them from proteins we eat. Or we have to obtain them from supplements that contain them in readily available forms, that our bodies can then use.

LYSINE is one of the critical amino acids which is needed to make the other proteins in the body. It is necessary to create muscle tissues. It is also necessary to produce hormones, enzymes and anti-bodies. It also has an important role in absorbing the Mineral Calcium, while it helps to reduce the loss of calcium in urine. It also lowers Cholesterol levels.

Like the amino acid GLUTAMINE, it also aids in healing and repairing of tissues and cells recovering from wounds. As a Binding Agent, it works in this way to help increase the number of new cells in a wound that is healing. And together with  the amino acid GLYCINE, it is also required to create Collagen, that is used for hair, nails, skin and the various connecting tissues in the body.

It is also a precursor to L-Carnitine, ( a compound found in most cells of the body ), derived from amino acids, that is essential for a proper and healthy functioning of the Nervous System. Carnitine carries LONG-CHAIN FATTY ACIDS  across the Mitochondria of the cells and then burns them into working energy. It then eliminates the toxins produced by that metabolic process out of the cells. Lysine is also vital for normal physical growth. Therefore, a lack of the amount of Lysine in the body can lead to various health issues, including slow physical growth, nausea, dizziness and fatigue.

Lysine is also a precursor for L-Carathine which is also necessary for healthy functioning of the Nervous System.

There has been much research during the last thirty years, that shows increasing the consumption of the Amino Acids of Arginine and LYSINE will help increase the production and release of Human Growth Hormone ( HGH ). Both of these amino acids are included in the GHR PLATINUM Hgh Releasers. These clinical studies and research trials clearly prove that LYSINE is a Growth Hormone Releaser ( GHR ).

Three of the research studies above involving Arginine also include LYSINE, proving that LYSINE is likewise a Releaser of Growth Hormone ( GHR ).

- L-GLUTAMINE - 

GLUTAMINE is a critical amino acid that supports healthy functioning of the Brain. It is vital for the synthesis of both RNA and DNA. Growth Hormone ( GH ) promotes a process that is called "NeuroGenesis". This is how new neurons are synthesized in the brain. It also supports the maintenance and functioning of existing brain cells.

In a like manner, Growth Hormone ( GH ) levels also affect the levels of NeuroTransmitters in the brain, which are critical for many activities and functions in the body. Specifically, GLUTAMINE is a powerful amino acid that is also precursor for the making of the NeuroTransmitters GABA and Glutamate. These brain NeuroTransmitters also help to regulate and support various Cognitive Functions, such as mood, concentration and memory. GABA is also included in the formulation of the GHR PLATINUM products as one of the HgH Enhancers.

Science researchers know that even small amounts of supplementing with additional GLUTAMINE are able to promote a positive increase in the levels of Growth Hormone ( GH ) in the body. Many research studies have shown that using just 2 mg of this powerful amino acid could temporarily elevate Human Growth Hormone ( HGH ) levels by as much as 78%.

GLUTAMINE is also precursor to making the amino acid ARGININE - which is clinically proven to support the increase in production and secretion of Growth Hormone ( GH ) in your Pituitary Gland. So when you eat more proteins that contain  Glutamine, or you increase your consumption with supplements, you enable your body to elevate the levels of ARGININE and the NeuroTransmitters GABA and Glutamate. And there are many research studies which have already shown that both Arginine and Glutamine stimulate the release of Growth Hormone.

So how does GLUTAMINE work to cause a release of your Growth Hormone? The NeuroTranmitter Glutamate has a significant part in stimulating the Somatotrophs in the Pituitary Gland. These are the particular cells in the Pituitary that actually cause the production and secretion ( release ) of Growth Hormone ( GH ).

There is also a link between Growth Hormone ( GH ) and Fat Burning in the body. GH stimulates the break-down of body fats, through a process called "Lipolysis". This is how fats and other lipids are broken down and converted to Fatty Acids.  Likewise, there is also a similar connection between Growth Hormone and the metabolism of Carbohydrates. This then has a direct impact of blood sugar levels. So GLUTAMINE plays an important role on the Digestive processes and also the subsequent conversion of Starches, Sugars and Fats into energy through healthy metabolism.

Thus this vital amino acid can have a positive affect on levels of body fat, sugar and weight loss. Thus it is important to keep sufficient levels of both GLUTAMINE ( and ARGININE ), which stimulate the production and release of your own natural Growth Hormone. This then benefits your overall health and well-being in multiple ways, both physically and mentally.

At the same time, by improving the metabolism of both Carbohydrates and Fats in the body, you can achieve weight loss or maintain a proper and healthy weight balance. The results will then cause a corresponding increase in the production and release of ( more of ) your own Human Growth Hormone ( HGH ). How does this happen?

Various clinical research studies clearly show and prove that excess BODY FAT, particularly BELLY FAT, will negatively slow down ( or decrease ) both the production and then the release of Growth Hormone ( GH ). The amount of FAT that men and women carry in their bodies, especially in their BELLIES, adversely impacts the production of Growth Hormone ( GH ) that is made and released from their Pituitary Glands. So losing weight, especially BELLY FAT, is one of the best things that you can do to boost the secretion of HGH. The GHR PLATINUM products can help you to do just that.

GLUTAMINE is also the most abundant amino acid found in the blood and in body fluids. There it has several important functions. It is used to create proteins, produce energy, and help with detoxification and removal of waste products, such as Ammonia, from Metabolic processes.

Furthermore, this amino acid is needed for proper Digestive Function ( as explained above ) and good Intestinal Health. It also supplies energy for White Blood Cells and for growth and maintenance of certain cells in the Intestines. There, this amino acid helps to maintain the barrier which is between the inside of the Intestines and the rest of the body. In this way, it enables you to maintain a healthy gut. This protects against getting what is called a "Leaky Gut". In this way, it works to support a healthy Immune System, which helps to protect you from infection, sickness and disease.

Deficiencies of this amino acid can occur when a person is experiencing a lot of stress, or has an illness or severe injury. In those times, the body actually needs an abundant supply of Glutamine for healing and recovery from wounds. Specifically, the body requires it for repairing damaged tissues and cells.  Consequently, if the body needs more Glutamine than it can make on its own, it must get it elsewhere. As a result, the body might then break down muscle proteins, in order to release more of this amino acid. This is what happens often times when a person gets sick or injured.

Excess stress causes levels of the Hormone CORTISOL to rise. This is why it is known as the "Stress Hormone". How does this affect HgH levels in the body? Researchers also know that CORTISOL can block the production of Growth Hormone. So if you can reduce the amount of stress you have in your body, by maintaining good levels of Glutamine - you also decrease the levels of CORTISOL that block the production and release of the very Growth Hormone ( GH ) you need and want.

Here is one research study that shows an increase of GLUTAMINE causes an increase in Growth Hormone levels:

Increased Plasma Bicarbonate and Growth Hormone After an Oral Glutamine Load

https://pubmed.ncbi.nlm.nih.gov/7733028/

"An oral GLUTAMINE load was administered to nine healthy subjects to determine the effect on Plasma Glutamine, bicarbonate, and circulating Growth Hormone concentrations.

"These findings demonstrate that a surprisingly small oral GLUTAMINE load is capable of elevating alkaline reserves as well as plasma Growth Hormone ( GH )."

- L-GLYCINE - 

L-GYCINE is the amino acid used the most in creating Collagen. Collagen is needed for the hair, nails, skin and various connecting tissues throughout the body. This amino acid also helps in making bones, muscle ( and energy in the muscles ) supporting healthy Brain Functioning, and supports proper and healthy Sleep Patterns.

Glycine is used to make the TriPeptide Glutathione ( an AntiOxidant found in the cells ). This substance is created from the 3 Amino Acids: Glutamic Acid, Cysteine, and GLYCINE. But as we get older, the ability of our bodies to make this important AntiOxidant decreases. Thus most likely we need to get more of it by supplements as we age.

The AntiOxidant Glutathione helps to prevent damage and disease to the organs ( especially the Liver ), tissues and cells that Free Radicals can cause. When damaged cells in the Liver form Fibrous Tissues, they can turn into scars. Or the Liver can become diseased through accumulation of excessive fat ( "Fatty Liver" ), alcohol consumption and immune attacks.

Glycine also works as a NeuroTransmitter. In this capacity, it works in the processing of motor and sensory information, which enables vision, hearing and movement. It also works by helping to calm the Central Nervous System. And similar to the amino acid Glutamine, the ability of our bodies to make it, can become negatively impacted during times of stress, sickness or injury. Therefore, it is necessary to help repair tissues and cells and for healing of wounds.

Finally, this amino acid is involved in the Digestive process. It helps to digest fats by managing the release of bile acids from the Gall-Bladder into the Small Intestine. Meanwhile, it works as a "Glucogenic Amino Acid", which means that the Liver can convert this amino acid into glucose ( sugar ).

GLYCINE is the second most common amino acid contained in the various proteins of the body. There have been many clinical research studies showing the link between increasing the amount of Glycine and a corresponding boost in the levels of Human Growth Hormone ( HgH ) in the body. Here are just some of them:

The Effect of Glycine Administration on the Characteristics
of Physiological Systems in Human Adults: A Systematic Review

https://pubmed.ncbi.nlm.nih.gov/37851316/

"Functional decline of Physiological Systems during Aging leads to Age-Related Diseases. Dietary Glycine increases healthy lifespan in model organisms. and might decrease inflammation in humans, suggesting its gero-protective potential. This review summarizes the evidence of Glycine administration on the characteristics of eleven Physiological systems in adult humans."

"The Nervous System demonstrated the most positive effects, including improved psychiatric ( mental ) symptoms from longer-term Glycine administration; longer-term GLYCINE administration improved sleep in healthy populations."

Stimulatory Effect of Glycine on Human Growth Hormone Secretion

https://pubmed.ncbi.nlm.nih.gov/622050/

"GLYCINE was administered orally to 19 non-Obese normal subjects and 12 subjects with partial gastrectomy. In the normal subjects, a clear and significant increase of serum Human Growth Hormone ( hGH ) level was observed."

"The facts demonstrated that GLYCINE is one of the stimulatory agents inducing the Pituitary Gland to secrete HgH."

Glycine Stimulated Growth Hormone Release in Man

https://pubmed.ncbi.nlm.nih.gov/7376793/

"The influence of GLYCINE, the simplest amino acid, on Pituitary Function has been investigated in the present study. Different doses ( 4, 8, or 12 grams ) of Glycine were intravenously infused over 15 or 30 min in normal subjects.

The dose of 4 or 8 grams [ of ] Glycine induced a significant increase in serum [ Growth Hormone ] GH; however, a more pronounced and significant increase in serum [ Growth Hormone ] GH levels was observed after infusion at a dose of 12 grams [ of ] GLYCINE."

"The present data suggests that GLYCINE might play an important role in the control of Hypothalamic - Pituitary function."

Reduced Plasma Glycine Concentration in Healthy and Chronically Diseased
Older Adults: a Marker of Visceral Adiposity { FAT }?

https://pubmed.ncbi.nlm.nih.gov/38616018/

"Previous studies have shown that a reduced plasma concentration of the amino acid [ GLYCINE ] GLY is associated with intra-abdominal obesity, but the mechanism remains unclear. This study aimed to investigate whether lower plasma
[ GLYCINE ] GLY concentrations in older adults are independently associated with ( visceral ) adiposity { condition of being FAT }, age, sex, presence of chronic disease, & glucose intolerance, and whether they are caused by a reduced [ GLYCINE ] GLY Whole-Body Production ( WBP ) and/or increased GLY disposal capacity."

"We studied 102 older adults ( 47 males / 55 females ). We assessed body composition and Visceral Adipose Tissue
( VAT ). The strong association between lower plasma [ GLYCINE ] GLY and increased { Visceral Adiposity Tissue } VAT mass in older adults was independent of age, sex, body weight, lean mass or body mass index, and the presence of COPD."

Reduced plasma [ GLYCINE ] GLY in older adults can be considered a marker of Visceral Adiposity, independent of sex, age, body composition, presence of chronic disease, and whole-body GLY production or clearance.

- L-TYROSINE - 

The Amino Acid - TYROSINE is made from Phenylalanine, one of the 8 "Essential" Amino Acids. Therefore, we must eat enough of Phenylalanine in our consumption of proteins, or else obtain it from taking supplements. Consequently, if we do not have enough of Phenylalanine, we will also be lacking in Tyrosine as well.

Tyrosine plays a role in the building of proteins. In this way, it is involved in the production of the various Thyroid Hormones ( Thyroxin ), which helps regulate Metabolism, Adreno-Cortical Hormones, Melanin ( a pigment that is found in the hair, skin and iris of the eyes ), Enzymes, and various NeuroTransmitters.

The NeuroTransmitters in our brains relate to our various Cognitive Abilities, such as mood, focus, concentration, memory, working memory, cognitive flexibility ( ability to switch tasks or change thoughts ) and following instructions.

Thus this amino acid is a precursor for the NeuroTransmitters / Hormones - Dopamine, Epinephrine, Norepinephrine,  Adrenaline and Noradrenaline. And these substances can affect the secretion of HgH in the Pituitary Gland.

Dopamine is critical for our mental functioning and mood. It regulates the reward and pleasure centers. This important
brain substance is also vital for memory and motor skills.

Adrenaline and Noradrenalin are hormones that are responsible for what is called the "Fight-or-Flight Response" in stressful situations. They enable our bodies to stand and fight, or flee and run - from a perceived or actual attack or harm.

In these ways, this particular amino acid helps to balance the affects of excessive physical and mental stress. When we are under a high level of stress, we often have difficulty thinking clearly and remembering things. Research studies have shown that supplementation with Tyrosine helped to improve such Cognitive Ability. Numerous other studies which have been conducted, proved that Tyrosine reduces anxiety and stress, and assists people to be more mentally alert.

Likewise, Tyrosine has a part in the making of "Enkephalins". These are special substances in the brain which provide pain-relieving effects to the body. They are critical to the healthy functioning of our brains, because they are responsible for transmitting nerve impulses and signals, and prevent conditions such as depression.

Additionally, this amino acid also plays a role in the regulation of Blood Pressure, and also helping to reduce BODY FAT. Finally, it is also an AntiOxidant, helping to protect the body from damage caused by Free Radicals to organs, tissues, muscles and cells.

There has been much research to discover how TYROSINE stimulates the Pituitary Gland to cause it to secrete ( more ) Growth Hormone ( GH ). This increased release of our GH, through the work of Tyrosine, may occur at particular times, especially when under stress.

One particular study found that it has a significant part in supporting increased levels of both HGH and IGF-1, especially under conditions of stress or during high-intensity workouts. Scientists believe that it works by activating the Enzyme, called Tyrosine Kinase, which then acts like a messenger, which signals the body to begin various metabolic processes related to the production and release of Growth Hormone ( GH ).

Moreover, according to various scientific studies, the ability of TYROSINE to elevate the release of our Human Growth Hormone ( HgH ), is increased - when it is combined with certain other Amino Acids. Thus research studies have already shown that combining TYROSINE with the Amino Acids ARGININE and LYSINE can cause a more significant boost in levels of HGH, when compared to taking it alone.

There is already plenty of research which concludes that elevating the intake of both ARGININE and LYSINE, especially when these two combined together, leads to an increased production and release of Growth Hormone ( GH ).

Effect of Tyrosine Supplementation on Clinical and Healthy Populations
Under Stress or Cognitive Demands - A Review

https://pubmed.ncbi.nlm.nih.gov/26424423/

"Consuming the amino acid Tyrosine ( TYR ), the precursor of Dopamine ( DA ) and Norepinephrine ( NE ), may counteract decrements ( gradual decreases ) in neurotransmitter function and cognitive performance. However, reports on the effectiveness of Tyrosine ( TYR ) supplementation vary considerably, with some studies finding beneficial effects, whereas others do not. Here we review the available cognitive/behavioral studies on Tyrosine ( TYR ), to elucidate whether and when TYR supplementation can be beneficial for performance."

"In contrast, TYROSINE ( TYR )does seem to effectively enhance Cognitive performance, particularly in short-term stressful and / or Cognitively demanding situations. We conclude that TYROSINE ( TYR ) is an effective enhancer of Cognition, but only when NeuroTransmitter function is intact and Dopamine ( DA ) and/or Norepinephrine ( NE ) is temporarily depleted."

Behavioral and Cognitive Effects of Tyrosine Intake in Healthy Human Adults

https://pubmed.ncbi.nlm.nih.gov/25797188/

"The amino acid Tyrosine is the precursor to the catecholamine NeuroTransmitters Dopamine and Norepinephrine. Increasing Tyrosine uptake may positively influence catecholamine-related psychological functioning."

"We conducted a systematic review to examine the effects of Tyrosine on behavior and Cognition. Fifteen studies were reviewed. All studies except one involved Tyrosine loading during a single test session. In most behavioral studies, there were no significant effects of Tyrosine on exercise performance."

"In contrast, Cognitive studies employing neuro-psychological measures found that Tyrosine loading acutely counteracts decrements ( gradual decreases ) in working memory and information processing that are induced by demanding situational conditions such as extreme weather or cognitive load."

"The buffering effects of Tyrosine on Cognition may be explained by Tyrosine's ability to neutralize depleted brain catecholamine levels. There is evidence that Tyrosine may benefit healthy individuals exposed to demanding situational conditions."

Tyrosine Promotes Cognitive Flexibility: Evidence From Proactive vs. Reactive Control During Task Switching Performance

https://pubmed.ncbi.nlm.nih.gov/25598314/

"Tyrosine ( TYR ), an amino acid found in various foods, has been shown to increase Dopamine ( DA ) levels in the brain. Recent studies have provided evidence that Tyrosine ( TYR ) supplementation can improve facets of Cognitive Control in situations with high Cognitive demands."

"Here we investigated whether Tyrosine ( TYR ) promotes cognitive flexibility, a cognitive-control function that is assumed to be modulated by Dopamine ( DA ). We tested the effect of TYR on proactive vs. reactive control during task switching performance, which provides a relatively well-established diagnostic of cognitive flexibility. In a Double-Blind, Randomized, Placebo-Controlled design, 22 healthy adults performed in a task-switching paradigm."

"Compared to a neutral placebo, Tyrosine ( TYR ) promoted Cognitive flexibility ( ie: reduced switching costs ). This finding supports the idea that Tyrosine ( TYR ) can facilitate Cognitive flexibility by repleting { filling / supplying } Cognitive resources."

Working Memory Reloaded: Tyrosine Repletes Updating in the N-Back Task

https://pmc.ncbi.nlm.nih.gov/articles/PMC3863934/

We tested the idea that the food supplement L-Tyrosine ( TYR ) repletes { provides / supplies } resources required for Cognitive-control operations. We investigated whether the “updating” ( and monitoring ) of Working Memory ( WM ) representations, a key Cognitive-control function, can be promoted by administering L-Tyrosine ( TYR ), the biochemical precursor of Dopamine ( DA ).

Interestingly, executive control has been considered to emerge from the interplay between cognitive stability ( defined as the maintenance of task-relevant representations ) and flexibility ( defined as the ability to adapt, update, and shift between informational states ) – two major, but partially antagonistic functions of cognitive control, (that are) related correspondingly to the PreFrontal Cortex ( PFC ) and the Striatum, which both are modulated by Dopamine ( DA ) - the precursor of which is L-Tyrosine (  TYR ).

The current study focused, for the first time, on the acute effect of L-Tyrosine (  TYR ) supplementation on the updating (and monitoring) of Working Memory ( WM ) representations – a key cognitive-control function. We tested whether WM updating can be promoted by administering the food supplement L-Tyrosine (  TYR ). We investigated the link between L-Tyrosine (  TYR ) supplementation and the monitoring of WM in healthy adults exposed to an oral dose of either L-Tyrosine (  TYR ) or a neutral placebo.

The present study is the first to demonstrate that Tyrosine supplementation promotes Working Memory ( WM ) updating. As expected, the more challenging 2-back condition was more sensitive to the effect of Tyrosine, which reinforces our suspicion that only tasks with considerable Cognitive demands benefit from Tyrosine. As we have argued in the introduction, this may be because more demanding Cognitive operations are more likely or more efficient to exhaust the available Cognitive resources, which can then be repleted { provided / supplied } by Tyrosine.

Tyrosine Hydroxylase Neurons Regulate Growth Hormone Secretion
via Short-Loop Negative Feedback

https://pmc.ncbi.nlm.nih.gov/articles/PMC7252485/

"Classical studies suggest that Growth Hormone ( GH ) secretion is controlled by negative-feedback loops mediated by Growth Hormone-Releasing Hormone ( GH - RH ) - or Somatostatin-expressing neurons."

The regulation of { Growth Hormone } GH secretion relies on the ability of these cells to sense changes in circulating GH levels to adjust Pituitary GH secretion within a narrow physiological range. However, our study identifies a specific population of TYROSINE hydroxylase-expressing neurons that is critical to auto-regulate GH secretion via a negative-feedback loop.

Increased Human Growth Hormone Following Oral Consumption of an Amino Acid Supplement: Results of a Randomized, Placebo-Controlled, Double-Blind, Crossover Study in Healthy Subjects

https://pmc.ncbi.nlm.nih.gov/articles/PMC6732240/

"Does an investigational amino acid supplement affect Hgh release? This was a Randomized, Placebo-Controlled, Double-Blind, crossover study that included 16 ( 12 males, 4 females ; Age 32 ±14 years ) healthy participants. All participants received both placebo and the amino acid supplement after an overnight fast and completed all study visits. Treatment order was randomized and each treatment was separated by a 1-week washout period."

"The primary outcome were the percent change in HgH from baseline to 120 minutes and the area under the curve of hGH over baseline. At 120 minutes, HgH levels increased by 682% ( 8-fold ) from baseline and were significantly higher than placebo.  In addition, a significantly higher mean AUC was observed for the amino acid supplement compared to placebo."

These results show that a single dose of the oral amino acid supplement was sufficient to significantly increase hGH levels in healthy adult males and females.