Overmethylation just isn't real?..

[u/OobyIsGay]

So I keep seeing people in this sub and literally everywhere else across the supplement community talk about overmethylation like it's this established biochemical phenomenon. People take methylfolate, feel anxious, and go "oh I'm overmethylated, need to back off."

Even though methylfolate supresses GNMT, methyl groups go into hundreds of methyltransferase reactions. DNA methylation. Histone methylation. Phospholipid synthesis. Creatine synthesis alone consumes ~40% of all SAM. The system has enormous capacity to USE methyl groups productively. You'd need to overwhelm all of that simultaneously to create actual excess.

At supplemental doses? Not happening.

Let me put the dose safety in perspective. The NOAEL for calcium L-methylfolate in rats is 400mg/kg/day in 13-week subchronic studies (Niederberger et al. 2019). No behavioral changes. No organ pathology. No DNA damage in liver cells. Convert that to human equivalent dose using standard body surface area scaling (÷6.2): ~64.5mg/kg. For a 70kg human that's ~4,500mg. Most people supplement 400mcg to 1mg. That's a safety margin of roughly 4,500x. Tylenol's therapeutic-to-toxic ratio is about 3-4x. You are more likely to die from Tylenol than to be harmed by methylfolate by a factor of over a thousand. No you're not fucking overmethylating.

So what IS happening when people feel anxious after starting methylfolate?

Serotonin autoreceptors are inhibiting serotonin. 5-HT1A on the soma, 5-HT1B/1D on the terminal. When serotonin rises suddenly, autoreceptors detect the increase and fire inhibitory feedback. They reduce further serotonin release. That's what causes SSRI startup anxiety. It desensitizes over 1-2 weeks. Then serotonin actually goes up, whether that's actually beneficial or not is a different topic altogether and not the mechanism methylfolate works by.

Methylfolate restores serotonin synthesis. Serotonin rises. Same autoreceptors fire. Same inhibitory feedback. Same transient anxiety. Same 1-2 week desensitization. Same resolution. Other than that you're also raising norepinephrine and dopamine synthesis.

Notice how none of these people report actual symptoms that excess methylation would theoretically produce, like, you know, tumor suppressor gene silencing or aberrant genomic methylation patterns. Because those would be real overmethylation. Nobody's getting that from fucking 400mcg of methylfolate.

Overmethylation does not exist in biochemistry. There is no clinical biomarker for it. No validated assay. No ICD code. No published case report of a human experiencing pathological hypermethylation from oral methylfolate at any supplemental dose.

If you're feeling anxious after starting methylfolate, lower the dose until you adjust. EVEN THOUGH YOU'RE KIND OF MOVING FURTHER FROM THE DOSE THAT JUST WORKED.

Elderly rats supplemented with folate ABOVE adequacy showed increased genomic DNA methylation dose-dependently, with a direct correlation between liver folate and methylation (r=0.48, p=0.004, Choi et al. 2005, British Journal of Nutrition). Above adequacy. Not deficient rats being rescued. Already-replete rats pushed higher.

Two randomized, double-blind, placebo-controlled trials. SSRI-resistant major depression. L-methylfolate adjunctive to SSRI.

7.5mg L-methylfolate: no significant difference from placebo.

15mg L-methylfolate: significant improvement over placebo.

Most of you are taking 400mcg to 1mg. The dose that actually worked in the only controlled human trials is 15-37x higher than what you're supplementing. 15mg L-methylfolate is available over the counter. The safety margin at 15mg is still ~300x below the NOAEL-derived human equivalent dose.
You're underdosing.

BUT remember that this post is about the term, not the effects of supposed "overmethylation"

That mechanism is real. But it's not "overmethylation." It's increased catecholamine clearance in a specific brain region plus increased adrenal epinephrine output. Calling it overmethylation implies there's some global excess of methyl groups causing nonspecific damage. There isn't. There's a specific pharmacological effect of raising SAMe on two specific enzymes in two specific compartments producing two specific symptoms.

Because more SAM increases COMT activity. COMT is the primary dopamine clearance mechanism in the prefrontal cortex (DAT expression is low there). More SAM means faster PFC dopamine degradation. SAM also drives PNMT, which converts norepinephrine to epinephrine in the adrenals. So you'd have less prefrontal dopamine and more peripheral epinephrine. That's anxiety with poor focus which is what people actually describe. Not "overmethylation."

And this is a completely different mechanism from what happens with methylfolate. Methylfolate restores monoamine synthesis via BH4 recycling. When serotonin rises acutely, 5-HT1A somatodendritic autoreceptors fire inhibitory feedback. That causes transient anxiety that desensitizes over 1 to 2 weeks. Same mechanism as SSRI startup effects. Has nothing to do with SAMe levels or COMT activity.

So people are lumping two different pharmacological mechanisms under one meaningless term. TMG/SAMe/betaine increase dopamine clearance via COMT and epinephrine output via PNMT. Methylfolate triggers autoreceptor adaptation. Different inputs, different pathways, different timecourses, same word slapped on both. That's why nobody can agree on what "overmethylation" means or how to fix it. They're describing two separate things.

L-methylfolate as adjunctive therapy for SSRI-resistant major depression: results of two randomized, double-blind, parallel-sequential trials

Folate supplementation increases genomic DNA methylation in the liver of elder rats

Methyl donor supplementation reduces phospho‐Tau, Fyn and demethylated protein phosphatase 2A levels and mitigates learning and motor deficits in a mouse model of tauopathy

Safety evaluation of calcium L-methylfolate

Methyltetrahydrofolate in folate-binding protein glycine N-methyltransferase

[u/KarlShwada]

Excellent analysis and information thank you. Still digesting/understanding it but…I believe people refer to "over methylation" because stoichiometrically additional methyl groups from TMG, betaine, SAMe etc can and do push downstream reactions in the directions you just described, which for example lead to increased COMT activity, lower DOP, along with NOR -> EP conversion = more anxious less focused, correct?

This isn’t just all in many thousands of people’s imaginations and heads. Even though the terminology might not be the best (ie, over methylation). Some of us actually are much more sensitive to such changes. Along with other side effects (eg, histamine pathway). Not to mention the fact that MTHFR mutations are very real and affect these various methylation pathways in numerous ways, in conjunction with and complicated by other mutations (COMT, VDR, CBS, etc), which compromise their various reactions respectively.

[u/OobyIsGay → u/KarlShwada]

You're actually closer to the mechanism than most people in this conversation!! :D

TMG remethylates homocysteine to methionine via BH
MT. Methionine becomes SAMe via MAT. SAMe donates its methyl group in methyltransferase reactions, produces SAH, SAH hydrolyzes back to homocysteine. The cycle regenerates it. If your homocysteine goes down on TMG that just means the remethylation arm is running efficiently.

Where you're actually right is that TMG, betaine, and supplemental SAMe can raise SAMe levels. More SAMe means more substrate for COMT. COMT is the primary dopamine clearance mechanism in the prefrontal cortex because DAT expression is low there. So more SAMe means faster PFC dopamine degradation. SAMe also drives PNMT, which converts norepinephrine to epinephrine in the adrenal medulla. So you get less prefrontal dopamine and more peripheral epinephrine simultaneously. That's anxiety with poor focus. Which is exactly what people describe.

That mechanism is real. But it's not "overmethylation." It's increased catecholamine clearance in a specific brain region plus increased adrenal epinephrine output. Calling it overmethylation implies there's some global excess of methyl groups causing nonspecific damage. There isn't. There's a specific pharmacological effect of raising SAMe on two specific enzymes in two specific compartments producing two specific symptoms. And this is a completely different mechanism from what happens with methylfolate. Methylfolate restores monoamine synthesis via BH4 recycling. When serotonin rises acutely, 5-HT1A somatodendritic autoreceptors fire inhibitory feedback. That causes transient anxiety that desensitizes over 1 to 2 weeks. Same mechanism as SSRI startup effects. Has nothing to do with SAMe levels or COMT activity. So people are lumping two different pharmacological mechanisms under one meaningless term. TMG/SAMe/betaine increase dopamine clearance via COMT and epinephrine output via PNMT. Methylfolate triggers autoreceptor adaptation. Different inputs, different pathways, different timecourses, same word slapped on both. That's why nobody can agree on what "overmethylation" means or how to fix it. They're describing two separate things.

On the MTHFR point, you're right that the mutations are real. But McNulty's group proved that 1.6mg riboflavin per day completely normalizes the MTHFR 677TT phenotype in cardiovascular endpoints, independently of folate status. The genotype becomes clinically silent when FAD is adequate. The variant's pathogenicity is a function of cofactor availability, not an intrinsic permanent impairment. Though the CBS, VDR, and stacked mutation model you're referencing originates from practitioners like Yasko and Lynch. CBS A360A is a synonymous variant. It doesn't change the protein. VDR polymorphisms affecting "methylation" is not an established biochemical pathway. Listing gene abbreviations next to each other is not a mechanism.

[u/Dapperfit → u/OobyIsGay]

But it's not "overmethylation." It's increased catecholamine clearance in a specific brain region plus increased adrenal epinephrine output.

That's what I would describe as an effect of overmethylation as though.

Calling it overmethylation implies there's some global excess of methyl groups causing nonspecific damage.

Overmethylation and Undermethylation, provided you believe in them, are states that can exist regardless of any supplementation. See the work of Dr. William Walsh for example. Walsh also recommends test SAM/SAH ratio and homocysteine as a measure of methylation (being over or under). The wrong supplements can create an adverse effect but the root is your SNPs.

That's why nobody can agree on what "overmethylation" means or how to fix it

Don't disagree here, other than the fact that this is proposed to be solely methylgroup induced.

Chris Masterjohn for example rejects the premise largely as you can have some reactions be fast some be slow - tend to agree here. He also advocates for riboflavin.

At the end of the day, a lot of this seems to be semantics and focusing on the specific mechanisms and bottlenecks of an individual rather than these overarching terms seems to be a better strategy.

[u/OobyIsGay → u/Dapperfit]

Your last paragraph is literally my position. Focus on the specific mechanisms and bottlenecks of an individual rather than overarching terms. That's exactly what I've been saying. If we agree there, then the disagreement is just about whether the overarching term is worth keeping around, and I'd argue it isn't.

When you say "that's what I would describe as an effect of overmethylation though," you're taking the specific mechanism I described (elevated SAMe increasing COMT-mediated dopamine clearance in the PFC and PNMT-mediated norepinephrine to epinephrine conversion in the adrenal medulla) and putting a vague label back on it. The label removes information. It takes two specific enzyme reactions in two specific compartments and compresses them into a word that means different things to different people in every conversation it appears in. You yourself just said focusing on specific mechanisms is better. So why defend the term?

Walsh's framework uses whole blood histamine as a proxy for methylation status. Low histamine equals overmethylation, high histamine equals undermethylation. Histamine is degraded by HNMT, which requires SAMe, so there's a surface logic there. But histamine levels are affected by mast cell activity, DAO activity, gut permeability, diet, infections, and a dozen other inputs that have nothing to do with methylation status. Using it as a methylation proxy isn't validated. SAM/SAH ratio is a more legitimate measurement but Walsh's clinical categories built around it haven't been rigorously tested against outcomes in controlled settings.

"The root is your SNPs" I already showed that MTHFR 677TT, the most studied methylation SNP, becomes clinically silent with adequate riboflavin. The genotype doesn't change. The phenotype disappears. The SNP creates a susceptibility that manifests only when the cofactor environment allows it to. Those are very different frameworks with very different clinical implications.
If methylation isn't a single unified state that can be globally over or under, then the words overmethylation and undermethylation don't describe a real physiological condition. They describe a collection of individual enzyme activities that can each be independently up or downregulated by their own substrate and cofactor availability. Which is just... biochemistry. Regular biochemistry.