11 replies to this topic

[Axmann8]

I've been reading some studies saying that glycine (a supplement that created some buzz a few years ago due to its apparent sleep-enhancing abilities) at high enough doses in humans is toxic partly due to the fact that glycine metabolism produces ammonia, which we all know certainly *is* neurotoxic.

Then again, these studies mostly (and in humans, virtually exclusively) involved the irrigation fluid used in TURP (Transurethral Resection of the Prostate), which contains glycine. So the actual exposure was probably much greater than what would occur with oral dosing.

There are also other studies plainly demonstrating direct neurotoxicity, but these are, of course, intraperitoneal-injection rat studies, so they are of extremely dubious value, if not completely useless.

Can I get some input on this? I'm sure it's just a matter of exposure as far as when symptoms start showing up, but if there is some underlying "mild" toxicity from glycine, is it worth taking?

I'd love some more input/discussion on this.

 

Human studies:
http://onlinelibrary...4046.x/abstract

http://www.indianjur...;aulast=Moorthy

https://www.karger.c...FullText/354933

http://onlinelibrary...006.06208.x/pdf

http://onlinelibrary...4411.x/abstract

 

Rat Studies:

http://www.sciencedi...014488697964633

http://www.ncbi.nlm....pubmed/15490133

http://www.researchg...lycine_is_toxic

[Axmann8]

Bump

[Groundhog Day]

Bump. Would love to hear people touch in on this. I've been using glycine for the past couple months to better my sleep a bit, 4-6grams at night and it's worked well. I've had chronic, severe insomnia that is hard to manage and the glycine recently stopped working. I'm not sure if it's the glycine or the PQQ i've been taking but one of them I believe is to blame for recent decline.

 

 

[Axmann8]

By the way, one of the studies above (https://www.research...lycine_is_toxic) actually discusses human effects. I incorrectly placed it under "rat studies" in my OP.

Edited by Axmann8, 08 March 2016 - 09:39 PM.

[Edogawa Rampo]

What Darryl says about it?

[Curtiss Harris]

Took 500 mg for about 2 months felt fantastic, slept great.   Decided to scale way back after some possible side effects,  weird leg thing and strange head sensation, so now I just micro dose.  Also added collagen peptide and my joints immediately stopped aching but I became quite allergic to that as evidenced by not being able to swallow properly so I quit that and it faded away....

[Keizo]

Has anyone else had a look at this?

 

From this thread it seems perfectly harmless: http://www.longecity...king-it/page-1 

Edited by Keizo, 08 July 2016 - 07:49 PM.

[RWhigham]

I have a mild case of essential tremor that started about 35 yr ago.

I suspect taking 10g/day of glycine for many months may have exacerbated my symptoms.

 

Scenario for Glycine neurotoxicity:

• Ca++ influx into neurons is controlled by "NMDA receptors", cell potential, and Mg+ ions.
• NMDA receptors have two activation points which must both be activated
• One part of NMDA is activated by glutamate and the other is normally activated by D-serene. Glycine can substitute for D-serine.
• D-serene is provided by neighboring astrocytes and is usually present.  Glycine is not normally present in high enough concentration.
• Although D-serene is usually present, it surely must have some control function.
• The control function of D-serene is overridden when extra glycine is present.
• Too much Ca++ influx can damage the neuron

 

More Detail:

• Glutamate reaches the NMDA receptor a little at a time with each firing of the neuron. Eventually enough accumulates to activate the NMDA
• When both sides of the NMDA receptor are activated, it opens access to the Ca++ channel in the neuron membrane
• The Ca++ channel is normally blocked by a large Mg++ ion held in place by the neuron's cell potential
• When the neuron cell potential is fully discharged, after a short delay the Mg++ ion drifts out of the way
• As the neuron starts to recharge, Ca++ rushes in before the pore is blocked again

Edited by RWhigham, 04 April 2017 - 05:16 PM.

[PeaceAndProsperity]

The fact that glycine may produce ammonia is completely meaningless to anyone taking it even if they take it in high dosages. Just completely ridiculous. Anyway, there are amino acids whose purpose is to remove ammonia from the body, like l-arginine or was it l-carnitine?

 

Silly thread, I'm sorry to say.

 

Now, as for side-effects of glycine, those exist. I've experienced weird paranoia and other issues. Maybe it was a contaminated batch, maybe glycine had decomposed to something (likely the case), who knows.

[Kabb]

 

I have a mild case of essential tremor that started about 35 yr ago.

I suspect taking 10g/day of glycine for many months may have exacerbated my symptoms.

 

Scenario for Glycine neurotoxicity:

• Ca++ influx into neurons is controlled by "NMDA receptors", cell potential, and Mg+ ions.
• NMDA receptors have two activation points which must both be activated
• One part of NMDA is activated by glutamate and the other is normally activated by D-serene. Glycine can substitute for D-serine.
• D-serene is provided by neighboring astrocytes and is usually present.  Glycine is not normally present in high enough concentration.
• Although D-serene is usually present, it surely must have some control function.
• The control function of D-serene is overridden when extra glycine is present.
• Too much Ca++ influx can damage the neuron

 

More Detail:

• Glutamate reaches the NMDA receptor a little at a time with each firing of the neuron. Eventually enough accumulates to activate the NMDA
• When both sides of the NMDA receptor are activated, it opens access to the Ca++ channel in the neuron membrane
• The Ca++ channel is normally blocked by a large Mg++ ion held in place by the neuron's cell potential
• When the neuron cell potential is fully discharged, after a short delay the Mg++ ion drifts out of the way
• As the neuron starts to recharge, Ca++ rushes in before the pore is blocked again

 

Hi RWhigham.  That's an interesting post about glycine.  For many months I used to take about 8 to 10 grams a day as an anti-inflammatory and tendon building block as recommended by Prof Joel Brind who feels such an amount was once provided by the average diet.  I never felt sleepy or relaxed from it although some people take it for this reason.

 

I have found I sometimes feel ill after taking glycine but I'm taking other supplements at the exact same time and may be singling out glycine unfairly.

 

I am very alert to the danger of excess Ca++ as you describe and I wonder if something like this may be occurring to me.

[Omega 3 Snake Oil]

Is it true that if someone tends toward glutamate toxicity then glycine is a bad idea?

http://nancymullanmd...d-gaba-balance/

"Glycine is also a special case neurotransmitter. If the balance in your body is towards glutamate, glycine will be excitatory. If the balance is toward GABA, it will be inhibitory. So if you tend toward glutamate excess, avoid glycine."
 

[Junk Master]

Noted strength coach Charles Poliquin recommends it highly for sleep quality, in large amounts, but I tend to agree with the above poster.  I'm more glutamate excess and it tended to wire me up a bit, even though once I was asleep, I did seem to have a better quality of sleep and woke up fewer times.