It definitely helps to keep me calm and cool like a cucumber.
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600mg/day of NAC, mostly for the mucoloytic effect. I know it’s gross but I quite often get blocked up sinuses or cough up mucus, and NAC is very powerful at dissolving it and making it watery.
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A good video to show your older friends and relatives:
Early Antioxidant Data (Vitamin E/A/C)
- Early large observational studies suggested higher vitamin E intakes were linked to lower heart disease risk, creating excitement for antioxidant supplements.
- However, randomized controlled trials did not confirm clear benefits from vitamins E, A, or C on mortality or major health outcomes. In fact, systematic reviews indicate that beta-carotene, vitamin A, and vitamin E supplements were associated with a slight increase in overall mortality in higher-quality trials.
- Later research showed that in younger adults, high-dose antioxidant supplements can interfere with natural adaptive responses to exercise and may not deliver the expected protection against aging.
GlyNAC (Glycine + NAC Supplementation)
- GlyNAC combines glycine and N-acetylcysteine, precursors for the body’s major antioxidant glutathione. Aging is associated with glutathione deficiency and elevated oxidative stress, which contribute to mitochondrial dysfunction and other aging hallmarks.
- Randomized clinical trials in older adults show that GlyNAC supplementation can restore glutathione levels, lower oxidative stress, and improve mitochondrial function, inflammation, insulin resistance, and physical function including strength and walking performance.
- Some evidence also points to improvements in cognition and body composition with GlyNAC in older individuals, and that these benefits decline when supplementation is stopped.
- Unlike traditional antioxidant vitamins, GlyNAC works by supporting the body’s own antioxidant system rather than supplying large doses of direct antioxidant compounds.
GPT summary of video transcript
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i am into my 2nd or 3rd week on 3g nac 3g glycine daily
i find that i really like the effects on my mood
i feel happier and more calm like u mentioned, its like the good mood supplement
From Google AI:
How GlyNAC May Support Mood
The potential benefits of GlyNAC for mood are related to several key mechanisms of action in the brain:
- Antioxidant Effects: Both NAC and glycine act as precursors to glutathione, the body’s primary endogenous antioxidant, which helps protect brain cells from damage caused by oxidative stress. Oxidative stress is a factor often associated with mood disorders, depression, and mental fatigue.
- Neurotransmitter Modulation: NAC helps regulate glutamate, a crucial neurotransmitter involved in memory and learning. Imbalances in the glutamate system are observed in various psychiatric conditions, and NAC may help promote healthier communication between brain cells.
- Anti-inflammatory Effects: Chronic inflammation is often linked to the development or exacerbation of psychiatric disorders. NAC has demonstrated anti-inflammatory properties by reducing certain pro-inflammatory cytokines, which may help improve mood.
- Neuroprotection and Mitochondrial Support: NAC helps support mitochondrial function, which is essential for healthy brain function and energy production. By protecting brain cells and supporting their energy centers, NAC may contribute to improved mood and cognitive resilience.
Research Findings on Mood
Clinical studies and meta-analyses have investigated NAC (often as an adjunct therapy) for a range of psychiatric and mood disorders, with findings suggesting:
- Depression and Bipolar Disorder: Some studies suggest that NAC, in doses typically ranging from 1,200 to 3,000 mg per day, may help reduce symptoms of depression and improve functioning in individuals with major depressive disorder and bipolar disorder, especially as an adjunct to conventional treatments. The effects may be more pronounced in people with higher levels of inflammation.
- Irritability and Social Functioning: NAC has shown promise in improving symptoms of apathy, social withdrawal, and irritability, particularly in individuals with schizophrenia or autism spectrum disorder (ASD).
- Compulsive Behaviors: Evidence suggests NAC may also help manage impulse control disorders such as pathological gambling, hair pulling (trichotillomania), and skin picking.
While the research is promising, experts note that many studies are underpowered or of limited duration, and more large-scale, long-term studies are needed to confirm the optimal dosages and full benefits of NAC or GlyNAC for mood disorders.
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does anyone experience an almost total loss of sex drive on glynac? lol
this has never happened to me before but i feel totally uninterested in sex (from twice a week to maybe twice or once a month) since upping my dose of glynac to 3g each, this is the most obvious change i noticed.
is it due to moderating of glutamate in my brain and hence reducing compulsions (of which sex is one) haha.
Not me. Check testosterone levels. Could be compulsion control, I have noticed less compulsions in eating. Eating more plain foods.
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I dug into AI searches and the internet and found plausible mechanisms why glycine (including magnesium glycinate) can impair libido.
Plausible Mechanisms, interesting but as always, this is mechanistic speculations:
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Glycine acts as an inhibitory neurotransmitter via GlyR receptors and NMDA modulation, which can dampen arousal and the reward system—dopamine is indirectly affected, a key factor for sexual motivation.
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Higher doses (3–6 g) can raise prolactin, which inhibits testosterone and desire. User reports in Reddit threads describe “a rapid drop in libido after glycine intake”, “tanked my libido right away,” and also that magnesium glycinate can cause inhibition.
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Edit/Update:
I went to really read up on this and stopped glynac for 2 days.
The best explanation is because the huge glycine doses (4-8g daily) I was taking (prob cus it was sweet and like sugar) was causing an increase in Serotonin (similar to taking an SSRI, which also kills libido). This also explains the good mood and calming effects I experienced and why the Baylor’s College guys mentioned that glynac is the power of 3…i.e. they don’t just increase glutathione…nac and glycine each also has their individual effects on the body.
High serotonin leads to a feeling of happiness and less motivation to seek pleasures externally…which explains why i get the constant feeling that I am calm, have a lot of self control and there is a loss of libido and a loss of desire to go shopping or buy food (my monthly expenditure has nv been so low before).
So in fact, if someone is depressed, they could just take higher doses of glycine.
I have stopped glycine for 2 days now, I can feel the effects waning and myself returning to normal. glycine and serotonin have short half lives so by 1-2 days it should be out.
Interesting, just FYI for those taking glynac as well. Lesson for me is to stick to 2-3g of each daily.
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you guys are describing the same effects as what i experienced. we are all experiencing the serotonin boost.
high serotonin allows someone to control their cravings for sugar and external gratification well. lol.
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i am back at 2g each daily.
here are some articles positing that NAC may increase the risk of cancer and an observational study on COPD patients in Taiwan that report the opposite.
https://www.science.org/content/blog-post/n-acetyl-cysteine-warning-shot
None of the aged normal mice showed signs of adenocarcinoma developing in their lung tissue. But 10% of the aged normals getting NAC supplementation showed it. None of the aged JudD knockouts showed any, either, but 50% of the aged JunD knockouts getting the NAC supplementation had it. The best guess is that cell senescence pathway that seemed to be inhibited with the NAC: some of these are in fact cells that should have died and didn’t, and went on to become cancerous:
To investigate how antioxidants might affect cancer progression, Martin Bergö, Ph.D., of the University of Gothenburg in Sweden, led a 2014 study in mouse models of human lung cancer. The researchers found that adding the antioxidants N-acetylcysteine (NAC) or vitamin E to the diet of mice with small lung tumors substantially increased the number, size, and stage of the tumors. Additional work showed that the NAC and vitamin E reduced levels of ROS and DNA damage in cancer cells, and essentially eliminated expression of the gene p53—a tumor suppressor gene that is typically activated by DNA damage.
These findings, Dr. Bergö said, provided a plausible explanation for why the male smokers who received antioxidants in the Alpha-Tocopherol, Beta Carotene Cancer Prevention Study in Finland had a higher incidence of lung cancer than those who received a placebo. The simplest explanation, Dr. Bergö said, is that when the trial recruited patients, many of them had small, undiagnosed lung tumors, which progressed more rapidly when they were given antioxidants.
In their most recent study, published October 7 in Science Translational Medicine, Dr. Bergö’s team examined the effects of antioxidants on melanoma. They chose to study melanoma because the incidence of melanoma is increasing in the United States and Europe, melanoma cells are sensitive to oxidative stress, and a good mouse model of melanoma already exists, Dr. Bergö explained.
Although supplementation of drinking water with NAC didn’t increase the number and size of the primary melanoma tumors in the mice, the researchers found that it doubled the number of lymph node metastases.
Dose-dependent relationships were observed, with higher daily NAC intake associated with reduced cancer risk. Time-varying Cox regression analysis demonstrated significant reductions in the risk of specific cancers, including hepatocellular carcinoma, colorectal cancer, and breast cancer, among NAC users compared to non-users. Our study provides clinical evidence supporting the potential anticancer effects of NAC in COPD patients. These findings highlight the importance of exploring NAC as a chemopreventive agent in high-risk populations and inform clinical practice and future research endeavors.
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Research in the 1990s was on the forefront of understanding the way supplements affect cancer cells and our body. These studies, which focused on beta-carotene and vitamin A, were stopped early when it was discovered that not only were the supplements not preventing lung cancer, but they were causing increased risk of developing lung cancer in people who were already at high risk. Following several other studies, there is enough evidence that physicians recommend smokers avoid taking beta-carotene supplements.
Researchers continue to examine antioxidants, and two recent studies found that antioxidants can actually make lung cancer spread or metastasize in certain types of lung cancer. A study from New York University School of Medicine showed how two tumor mutations, common in about 30% of non-small cell lung cancer, can help the lung cancer cells make their own antioxidants which causes the cancer to metastasize through a sophisticated cellular pathway. A study from the Karolinska Institute in Stockholm also showed that when given long term, the supplements N-acetylcysteine and vitamin E help lung cancer spread in tissue with the KRAS mutation. Both studies examine the role of a protein called Bach1. When antioxidants eliminated oxidative stress, they unknowingly protected tumors and prompted the buildup of Bach1 which increases the uptake and use of glucose, or sugar, giving cancer the energy needed to spread.
So, what does all this mean for patients? We asked Anthony Alberg, Ph.D., MPH, an epidemiologist who has studied lung cancer and nutrition. “As we learn more and more about how complex cancer cells are and how they figure out ways to survive and grow, working against the normal cellular constrictions, it makes us understand why they are so hard to fight.” Dr. Alberg continued. “The hope is that the more we can understand these pathways, maybe we can better understand ways to control cancer and new treatments can be developed.”
It is this hope that has scientists excited about the findings of these studies. Identifying this powerful “promoter of metastasis” could help doctors better advise patients about what, if any, role supplements may have and understand that certain cancers may act differently in the presence of supplemental antioxidants.
For now, experts agree that patients should aim to get all of their nutrients from a natural, balanced diet rich in fresh fruits and vegetables; not supplements, unless otherwise directed by a doctor. But each person’s dietary needs are unique, which is why it is also recommended that people being treated for lung cancer consult a doctor or a registered dietitian nutritionist.
The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study demonstrated that β-carotene supplementation increases lung cancer incidence in smokers. Further, cigarettes with higher tar and nicotine content are associated with a higher risk of lung cancer. However, no studies have examined whether the increased risk associated with β-carotene supplementation in smokers varies by the tar or nicotine content of cigarettes.
### Methods
The ATBC Study was a randomized, double-blind intervention trial conducted in southwest Finland. A total of 29 133 male smokers, aged 50–69 years, were enrolled and randomly assigned to one of four groups (α-tocopherol, β-carotene, both, or placebo). Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% confidence intervals (CI) of lung cancer risk by β-carotene trial assignment stratified by a priori categories of cigarette tar and nicotine content.
### Results
The β-carotene supplementation group had significantly higher risk of developing lung cancer in all categories of tar content (yes vs. no β-carotene supplementation—ultralight cigarettes [≤7 mg tar]: HR = 1.31, 95% CI = 0.91 to 1.89; nonfiltered cigarettes [≥21 mg tar]: HR = 1.22, 95% CI = 0.91 to 1.64; p for interaction = .91). Similarly, there was no interaction with nicotine content (yes vs. no β-carotene supplementation—ventilated cigarettes [≤0.8 µg nicotine]: HR = 1.23, 95% CI = 0.98 to 1.54; nonfiltered cigarettes [≥1.3 µg nicotine]: HR = 1.22, 95% CI = 0.91 to 1.64; p for interaction = .83).
### Conclusion
These findings support the conclusion that supplementation with β-carotene increases the risk of lung cancer in smokers regardless of the tar or nicotine content of cigarettes smoked. Our data suggest that all smokers should continue to avoid β-carotene supplementation.
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Just a little further background. It has been know for decades that vitamin A is a problem for smokers and lung cancer. Always was a strange association but always felt (by me at least) a unique situation. I don’t think the effect should be extrapolated to any thing else.
Beta carotene just a pre vitamin A molecule of sorts.
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Only high Vitamin A. Not the RDA
How annoying. I’d be interested to hear other peoples view on this.
The interesting part is that beta carotene is supposed to be safer because you “can’t” overdo it because the body only converts what is needed.
So you get yellow from too many carrots but not vitamin A toxic. But you would impact lung cancer presumably.
A sweet potato has 400% of the rda for vitamin A and is almost a high dose supplement.
Also, smoking depletes vitamin A in lung tissue and systemically and low vitamin A increases risk of cancer. So damned if you do, damned if you don’t.
This confusing picture is not seen anywhere else that I know of which is why I consider it a one-off.
I find lots of references saying lung cancer patients should eat sweet potatoes and that sweet potatoes reduce the risk of lung cancer. One, for former smokers, is behind a paywall so I can’t even get a real link.
I just learned they took beta carotene out of the AREDS vitamin because of this cancer risk. Seems to me this isn’t ideal for all the non smokers out there.
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our body is complex
antixoidants help reduce ROS and protect genomic integrity
but it seems like too much of them is posited to surpress enzymes such as p53 or increase Bach1 etc which may increase the risk of lung cancer (not sure about other cancers) up to 30% in smokers.
maybe we should:
- not overdo the doses, stick within limits
- cycle on and off
- understand the potential risks and benefits and follow the science… i think maybe this is something our current edge of science has not fully understood yet
this is an interesting mouse study which shows NAC actually drastically reduces cancer in p53 knockout mouse and gave them a normal lifespan. so the idea that NAC supresses p53 and that causes an increase in cancer is at odds with this study where there is no functioning p53 already but NAC prevents cancer and extends lifespan
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Here’s a good meta review and analysis of cysteine
https://onlinelibrary.wiley.com/doi/10.1111/acel.14392
4.1 On the mouse studies
In mice, supplementation with cysteine was found to significantly reduce the risk of death and extend survival time. Subgroup analysis revealed that these effects were independent of the dose, administration method, and genetic background (inbred vs. noninbred, transgenic vs. nontransgenic). It should be noted that, however, the AKR and C3H mice used in two studies develop spontaneous cancers and have shorter lifespans (Harman, 1957, 1961). Indeed, most included mouse studies utilized disease models, like amyotrophic lateral sclerosis (Andreassen et al., 2000; Kurano et al., 2022), lymphoma (Reliene & Schiestl, 2006), premature aging (Kondratov et al., 2009), Huntington’s disease (Paul et al., 2014), renal tubulointerstitial injury (Jin et al., 2014), senescence-associated vitamin D deficiency (Chen et al., 2019), diabetes (Frenkel et al., 2019), and pulmonary fibrosis (Chen et al., 2020). All these studies used NAC and found positive effects. In studies using wild-type animals, no consistently significant improvement was found. Cysteine hydrochloride did not increase the lifespan of male Swiss mice (Harman, 1961) but co-administration of glycine and NAC prolonged the lifespan of C57BL/6J mice (Kumar et al., 2022). To reduce the risk of inbreeding depression and overgeneralizing strain-specific findings, Flurkey et al. used the genetically heterogeneous HET3 mice and found that NAC did not affect the lifespan of female mice. The lifespan of male mice was extended but this might be due to diet restriction because reduced food uptake was observed (Flurkey et al., 2010). Using genetically heterogeneous animal models is important in aging studies.
The form of cysteine does affect the outcomes in mice. Cysteine hydrochloride and NAC are both commonly encountered derivatives of cysteine. Despite sharing certain chemical structural similarities, they diverge in terms of usage, as well as human absorption and utilization. Specifically, NAC is an acetylated form of cysteine. Upon oral administration, it is rapidly absorbed in the gut, delivered to the liver, and hydrolyzed to cysteine. This sequence of events ultimately results in a higher rate of oral absorption and utilization for NAC (Dilger & Baker, 2007; Pei et al., 2018) which may partly explain why only the administration of NAC, but not cysteine hydrochloride, impacted lifespan.
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In one of the studies posted at the beginning of the thread, there was no glutathione regeneration effect when taking 1.2g of each NAC and glycine but there was at 2.4g of each and 3.6g of each in healthy older adults (average age 65). I think 2.4g of each is probably the lowest effective dose for glutathione restoration and more is better.
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yes that makes sense cus we ingest 1-2g of cysteine from our diet daily. so conceivably to raise glutathione beyond what our normal diet provide, 2-3g of NAC is likely needed.
but then there are also the studies on high dose beta carotene (20mg daily, super high, like 30k IU of vitamin A), vit e and NAC (high dose of 7g each humans equivalent) on smokers and wild type mouse models that show increased lung cancer risk (10% for normal wild type mouse but the sample was super small and being wild type, some types are more prone to cancer naturally than others we dont know the breed of those mouse) as well as risks of making cancers spread.
there could be design issues or just flukes with those studies but they deserve thought.
The NAC and cancer link was disproven by recent studies. Vitamins A and E though do have a cancer link and should not be supplemented.
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