# Is glycine a safe supplement? **URL:** \ **Category:** General\ **Created:** [April 6, 2024, 6:10am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161 "2024-04-06T06:10:31Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Test\_Min\_Tele](https://www.rapamycin.news/user_avatar/www.rapamycin.news/test_min_tele/32/15468_2.png) [@Test\_Min\_Tele](https://www.rapamycin.news/u/Test_Min_Tele)\ **Post date:** [April 6, 2024, 6:10am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/1 "2024-04-06T06:10:31Z")
Is glycine a safe dietary supplement? read a while ago about some connection with cancer but have also read that it is beneficial for longevity. have taken it quite a bit as it has a good effect on sleep. (2g) ---
**Author:** ![TARM](https://www.rapamycin.news/letter_avatar_proxy/v4/letter/t/779978/32.png) [@TARM](https://www.rapamycin.news/u/TARM)\ **Post date:** [April 6, 2024, 7:02am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/2 "2024-04-06T07:02:32Z")
Yes. As its not unusual for seniors to ve lacking. Other drugs like SSRI decrease the hepatic conversion to synthesize glycine. Do a search there is another long thread discussing it. I use between 2-10g/d. Its nice as it hasa mildly sweet taste so compared to 99% of supplements it tastes pleasant and you just use a scoop into your mouth and let it disolve and swallow. ---
**Author:** ![John\_Hemming](https://www.rapamycin.news/user_avatar/www.rapamycin.news/john_hemming/32/6542_2.png) [@John\_Hemming](https://www.rapamycin.news/u/John_Hemming)\ **Post date:** [April 6, 2024, 7:03am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/3 "2024-04-06T07:03:36Z")
Glycine, however, is often one of the main amino acids in collagen powder. Hence if you take sufficient collagen supplementing with Glycine additionally may not be much use. ---
**Author:** ![TARM](https://www.rapamycin.news/letter_avatar_proxy/v4/letter/t/779978/32.png) [@TARM](https://www.rapamycin.news/u/TARM)\ **Post date:** [April 6, 2024, 7:08am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/4 "2024-04-06T07:08:53Z")
Here’s the thread > [@Glycine+NAC vs Rapamycin](https://www.rapamycin.news/t/glycine-nac-vs-rapamycin/1500): > > ITP study showed a 6% life extension in mice by Glycine, another study showed a 20% life extension in mice my Glycine + NAC (N-Acetyl Cysteine), That is close to Rapamycin territory. Rapamycin inhibits MTOR, and thats the theory on the reasons of longevity. Amino acids activate MTOR and Glycine and NAC are amino acids, so should in theory not be longevity candidates. I am using Glycine 8mg and NAC 3mg a day, started 3 weeks ago after reading the results from the mouse study and reading about other benefits of this supplement combo. I have to say that after a week or so I felt amazing, much more energy, never tired after exercise and lots of libido. I will receive my first batch of Rapamycin in a week or 2 from Singapore, hopefully it will not be confiscated in customs. Can I use Glycine+NAC together with Rapamycin? or should I choose one or the other? ---
**Author:** ![DeStrider](https://www.rapamycin.news/user_avatar/www.rapamycin.news/destrider/32/19418_2.png) [@DeStrider](https://www.rapamycin.news/u/DeStrider)\ **Post date:** [April 6, 2024, 7:15am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/5 "2024-04-06T07:15:43Z")
Glycine is safe regarding cancer. Serine is not. ---
**Author:** ![LukeMV](https://www.rapamycin.news/letter_avatar_proxy/v4/letter/l/7cd45c/32.png) [@LukeMV](https://www.rapamycin.news/u/LukeMV)\ **Post date:** [April 6, 2024, 2:09pm UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/6 "2024-04-06T14:09:56Z")
Do we need to get extra glycine if we already consume collagen peptides simultaneously with NAC? ---
**Author:** ![DeStrider](https://www.rapamycin.news/user_avatar/www.rapamycin.news/destrider/32/19418_2.png) [@DeStrider](https://www.rapamycin.news/u/DeStrider)\ **Post date:** [April 6, 2024, 3:36pm UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/7 "2024-04-06T15:36:48Z")
It depends on the type of collagen and how much. If you are taking 2X or more grams of collagen than NAC, I’d say that’s the minimum. I’d probably want to see 3-4X to fully utilise the NAC. ---
**Author:** ![TARM](https://www.rapamycin.news/letter_avatar_proxy/v4/letter/t/779978/32.png) [@TARM](https://www.rapamycin.news/u/TARM)\ **Post date:** [April 7, 2024, 4:17am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/8 "2024-04-07T04:17:09Z")
> [@DeStrider](#): > > Glycine is safe regarding cancer. Serine is not. In fact glycine can be helpful in cases of liver cancer as supplying enough glycine downregulates the enzyme serine hydroxymethyltransferase (SHMT) which is normally used to syntheize glycine. SHMT is known to increase proliferation of malignate cells. Here is a good explanation of the entire various pathways involved: [Glycine and Serine Metabolism](https://pubchem.ncbi.nlm.nih.gov/pathway/PathBank:SMP0000004) ---
**Author:** ![Vlasko](https://www.rapamycin.news/user_avatar/www.rapamycin.news/vlasko/32/33802_2.png) [@Vlasko](https://www.rapamycin.news/u/Vlasko)\ **Post date:** [April 7, 2024, 7:16am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/9 "2024-04-07T07:16:07Z")
> [@John\_Hemming](#): > > Glycine, however, is often one of the main amino acids in collagen powder. Hence if you take sufficient collagen supplementing with Glycine additionally may not be much use. It may be. Glycine at 8% diet extended both median and maximum lifespan in rats by roughly 30%. And rats may be a better model for gerontological research than mice. (Allometric scaling needed for human dosing estimate). Study Title: “[Dietary glycine supplementation mimics lifespan extension by dietary methionine restriction in Fisher 344 rats.](https://scholar.google.com/scholar_lookup?journal=The+FASEB+Journal&title=Dietary+glycine+supplementation+mimics+lifespan+extension+by+dietary+methionine+restriction+in+Fisher+344+rats&volume=25&publication_year=2011&pages=528&#d=gs_qabs&t=1655911247568&u=%23p%3DH9cYPkKLxgEJ)” The FASEB Journal 25, 528.2-528.2, 2011. Joel Brind, Virginia Malloy, Ines Augie, Nicholas Caliendo, Joseph H Vogelman, Jay A Zimmerman, Norman Orentreich ---
**Author:** ![Test\_Min\_Tele](https://www.rapamycin.news/user_avatar/www.rapamycin.news/test_min_tele/32/15468_2.png) [@Test\_Min\_Tele](https://www.rapamycin.news/u/Test_Min_Tele)\ **Post date:** [April 7, 2024, 1:40pm UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/10 "2024-04-07T13:40:58Z")
Thank you very much for all the answers! ---
**Author:** ![Vlasko](https://www.rapamycin.news/user_avatar/www.rapamycin.news/vlasko/32/33802_2.png) [@Vlasko](https://www.rapamycin.news/u/Vlasko)\ **Post date:** [April 7, 2024, 8:20pm UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/11 "2024-04-07T20:20:46Z")
> [@Vlasko](#): > > It may be. Glycine at 8% diet extended both median and maximum lifespan in rats by roughly 30%. And rats may be a better model for gerontological research than mice. (Allometric scaling needed for human dosing estimate). Dosing estimate based on allometric scaling. Note that this is for glycine alone, not with NAC. Glycine at 8% diet is 80,000 ppm feed. To convert from ppm feed in rats to mg/kg bodyweight in humans: **Step 1** : Convert PPM in rat chow to mg/kg bodyweight in rats by multiplying by a factor of 0.05: 80,000 × 0.05 = 4000 mg/kg (\*) **Step 2** : Apply allometric scaling to convert from rat to human (divide by 6.2): 4000 mg/kg ÷ 6.2 = 645.16 mg/kg. (\*\*) **Step 3** : Multiply by human weight in kg to determine personal dosage estimate. For example, a 70 kg person: 645.16 mg/kg × 70 kg = 45,161.2 mg. Approximately 45 grams daily in divided doses for a 70 kg person. Tables: ![PSX_20231203_173017](https://www.rapamycin.news/uploads/default/original/3X/0/d/0ded0a27d25e7d698254842e956b8e0a623b09c6.jpeg) ![PSX_20231203_173411](https://www.rapamycin.news/uploads/default/original/3X/3/d/3d17d2be1c2b86e0238f2483b8fea571b8ecc4ed.jpeg) Sources: (\*) Nair A, Morsy MA, Jacob S. Dose translation between laboratory animals and human in preclinical and clinical phases of drug development. _Drug Dev Res_ . 2018;79(8):373-382. doi:10.1002/ddr.21461. (\*\*) Nair AB, Jacob S. A simple practice guide for dose conversion between animals and human. _J Basic Clin Pharm_. 2016;7(2):27-31. doi:10.4103/0976-0105.177703 ---
**Author:** ![Rapamune1](https://www.rapamycin.news/user_avatar/www.rapamycin.news/rapamune1/32/549_2.png) [@Rapamune1](https://www.rapamycin.news/u/Rapamune1)\ **Post date:** [April 8, 2024, 12:00am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/12 "2024-04-08T00:00:59Z")
Glycine mimics meth, nine restriction diet. Selenium also mimics methionine restriction diet. [Selenium supplementation inhibits IGF-1 signaling and confers methionine restriction-like healthspan benefits to mice - PMC](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8009673/) ---
**Author:** ![DeStrider](https://www.rapamycin.news/user_avatar/www.rapamycin.news/destrider/32/19418_2.png) [@DeStrider](https://www.rapamycin.news/u/DeStrider)\ **Post date:** [April 8, 2024, 12:49am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/13 "2024-04-08T00:49:10Z")
However too much Selenium is toxic. Too much Glycine is not. It’s hard to get 45 g of Glycine daily, and, honestly, that seems like way too much. I always thought 15 g (which I take daily) was already quite a bit! ---
**Author:** ![Vlasko](https://www.rapamycin.news/user_avatar/www.rapamycin.news/vlasko/32/33802_2.png) [@Vlasko](https://www.rapamycin.news/u/Vlasko)\ **Post date:** [April 8, 2024, 3:11am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/14 "2024-04-08T03:11:58Z")
> [@DeStrider](#): > > It’s hard to get 45 g of Glycine daily, and, honestly, that seems like way too much. I always thought 15 g (which I take daily) was already quite a bit! This high of a dose would need to be divided. For example, if someone weighed 70 kg and wanted to take 45 grams daily, then 15 grams every eight hours. Or dividing into four doses. Studies have used up to 90 grams daily for extended periods. However, that is in divided dosages. If this much was taken all at once, it may produce mild toxicity like mental fatigue and probably wouldn’t serve its purpose for anti-aging, because the idea would be to keep replenishing the liver with fresh glycine and not OD’ing in a single bolus. I’m not necessarily advocating such a high dose as the 45 gram amount, but I did the calculations to show what it would be with basic allometric scaling. ---
**Author:** ![DeStrider](https://www.rapamycin.news/user_avatar/www.rapamycin.news/destrider/32/19418_2.png) [@DeStrider](https://www.rapamycin.news/u/DeStrider)\ **Post date:** [April 8, 2024, 4:04am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/15 "2024-04-08T04:04:20Z")
I understand and agree. Even with 15 g daily, I break it up into 2-3 doses. ---
**Author:** ![Rapamune1](https://www.rapamycin.news/user_avatar/www.rapamycin.news/rapamune1/32/549_2.png) [@Rapamune1](https://www.rapamycin.news/u/Rapamune1)\ **Post date:** [April 9, 2024, 7:23pm UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/16 "2024-04-09T19:23:16Z")
That logic does not make sense, if you take too much vitamin D for example that is also toxic If you take too much. Selenium has its place as an anti-aging benefit. Especially as a methionine restriction mimicker. ---
**Author:** ![DeStrider](https://www.rapamycin.news/user_avatar/www.rapamycin.news/destrider/32/19418_2.png) [@DeStrider](https://www.rapamycin.news/u/DeStrider)\ **Post date:** [April 9, 2024, 10:33pm UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/17 "2024-04-09T22:33:05Z")
Of course Selenium has it’s place. It just has a much lower threshold before it goes from a benefit to a detriment. I take Selenium, but I make sure not to take too much. Glycine has a much higher threshold. I would concede that you are right. There is a point where everything can be taken in too high of a quantity. However, I would argue that if you take 45 g of Glycine and 45 g of Selenium daily, the Selenium is going to cause you problems a lot sooner. The former is safe. The latter is dangerous. ---
**Author:** ![TARM](https://www.rapamycin.news/letter_avatar_proxy/v4/letter/t/779978/32.png) [@TARM](https://www.rapamycin.news/u/TARM)\ **Post date:** [April 10, 2024, 6:40am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/18 "2024-04-10T06:40:09Z")
The issue is how close in dosages is what gives optimal positive effects and the dose that causes toxic effects. Further is the toxic effect acute or does it require more chronic dosing. I also agree that selenium is far easier to overdose than glycine. Simply eating an couple extra brazil nuts each day can cause toxic effects. Thats has its own set of issues in that most people would never think 3-5 indivual nuts per day could cause selnium toxicity. Fentanyl dosing regardless that its in mcg the dose that creates effective pain control or sedation for procedures abd the dose that causes significant respitory supression is very small and highly variable, morphine or even hydromorphone (Dilaudid) has a much larger window in pain control vs sedation/respitory suppression. This is why most hospitals changed their policy and fentanyl can only be admistered in the ER or ICU where patients have constant monitoring. These changes were long before China started dumping metric tons of it onnthe streets so it was not from DEA or gov political pressure. Glycine would take large dosages and extended chronic dosing at that level to eventually have toxic effects possibly thru its metabolites or some pathway effect of chronic suppression or activation. Choice between downing a bottle of selnium vs a tub of glycine, I will take glycine everytime. Plus it tastes good, mildly glucose sweet. ---
**Author:** ![Vlasko](https://www.rapamycin.news/user_avatar/www.rapamycin.news/vlasko/32/33802_2.png) [@Vlasko](https://www.rapamycin.news/u/Vlasko)\ **Post date:** [April 12, 2024, 6:57pm UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/19 "2024-04-12T18:57:45Z")
Aside from the rat study, 8% glycine diet was also tested in mice in the ITP study at three sites as previously mentioned. And it extended lifespan at all three sites, but the effects were modest in comparison. The researchers noted that in the mice supplemented with 8% glycine, “there is no evidence from this work that glycine supplementation impairs health.” [Source](https://onlinelibrary.wiley.com/doi/full/10.1111/acel.12953) With regard to rats, they may be a better choice than mice for lifespan studies. > **[Rats - The Animal Model...](https://www.cyagen.com/us/en/community/technical-bulletin/rat-model.html)** > > Rats are physiologically, morphologically, and genetically closer to humans than mice, which makes rats ideal models for biomedical and clinical studies. Its larger body and organ size facilitate multiple samplings, in vivo electrophysiology, as well... ---
**Author:** ![mondagai](https://www.rapamycin.news/user_avatar/www.rapamycin.news/mondagai/32/26507_2.png) [@mondagai](https://www.rapamycin.news/u/mondagai)\ **Post date:** [February 7, 2025, 8:45am UTC](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161/20 "2025-02-07T08:45:15Z")
I’ve experienced a strong allergic reaction on a number of occasions. After a process of elimination, I now strongly suspect was caused by glycine. The symptoms; a red itchy rash covering my entire body shortly after taking glycine (~1 hour), and that lasts for around ~3 hours + diarrhea and nausea. I was honestly very surprised because this was the _last thing_ I thought might be the cause. I’ve since done a quick google, and there seems to be a number of people with histamine intolerance and mast cell disorders reporting similar things. The only place I could find anything on this was the HistamineIntollerance subreddit, so I’m putting this out there since I’m sure there are plenty of people here that supplement with glycine. [Next page](https://www.rapamycin.news/t/is-glycine-a-safe-supplement/13161.md?page=2)