If you're taking Nicotinamide Riboside (NR) or NMN to elevate NAD+ but aren't adding TMG, you're doing half the job. NR consumes methyl groups to function — your body uses them to convert it into NAD+ — and that consumption can spike homocysteine, a cardiovascular risk marker nobody wants elevated. TMG (trimethylglycine, also called anhydrous betaine) is the methyl donor that replenishes that stock and keeps your methylation cycle running cleanly.
The problem is that most NAD+ protocols on the market ignore this. They sell you NR alone, hoping you won't read the studies showing homocysteine elevation. In this article we break down what TMG is, how the methylation cycle works, what dose you need, and why any serious NAD+ protocol should include it as standard.
In summary:
- TMG donates methyl groups that NR/NMN consume when elevating NAD+
- Reduces homocysteine (cardiovascular risk marker) by 10–20% in studies
- Supports fatty liver, memory and physical performance as a bonus
- Dosage: 500–1000 mg/day, taken alongside NR/NMN
- Without it, NR can raise homocysteine in some people (ChromaDex studies confirmed this)
What is TMG (trimethylglycine) and why it's not just another supplement
TMG is the commercial name for trimethylglycine, also known as anhydrous betaine. It's a derivative of the amino acid glycine found naturally in beetroot, spinach, quinoa and wheat germ. Your body uses it as a methyl group donor — small chemical structures (CH₃) involved in hundreds of biochemical reactions.
Why does it matter? Because your body needs methyls to:
- Synthesise neurotransmitters (dopamine, serotonin, noradrenaline)
- Repair DNA and regulate gene expression (DNA methylation)
- Produce creatine, carnitine, phosphatidylcholine
- Recycle homocysteine into methionine (methylation cycle)
When you take NAD+ precursors like NR or NMN, your demand for methyls increases. NR is converted to nicotinamide, which your body methylates (adds a methyl group) to excrete it. If your methyl stock is low, homocysteine rises. TMG enters as backup, donating methyls to keep the cycle running cleanly.
TMG is not optional in NAD+ protocols. It is metabolic infrastructure.
How the methylation cycle works (and why NR stresses it)
The methylation cycle is a biochemical motorway that converts homocysteine into methionine (the essential amino acid that donates methyls). You need two routes to complete it:
- Folate + B12 route: uses folate and vitamin B12 to donate methyls
- TMG route: uses trimethylglycine as a direct donor
When you take NR:
- NR → NAD+ → nicotinamide (by-product)
- Your body methylates the nicotinamide to excrete it (it becomes N-methylnicotinamide)
- That methylation consumes methyl groups from the cellular pool
- If the pool becomes depleted, homocysteine is not recycled and accumulates
Studies in mice and humans show that high doses of niacin/NR can elevate homocysteine by 10–15% if there isn't sufficient methyl backup. TMG cuts that problem at the root by donating methyls in the homocysteine → methionine conversion.
Study-backed benefits: beyond methylation
Although TMG's main role in longevity protocols is methylation support, research shows additional benefits:
1. Homocysteine reduction
Meta-analysis of 12 clinical trials (2010, Nutrition Journal) reports that 500–6000 mg/day of TMG reduces plasma homocysteine by 10–20% in adults with normal-to-high levels. The reduction is dose-dependent and is observed within 6–12 weeks.
2. Liver protection
TMG supports liver function by donating methyls for phosphatidylcholine synthesis, a component of cell membranes. Studies in non-alcoholic fatty liver disease (NAFLD) show that 1.5–6 g/day improves liver enzyme markers (ALT, AST) within 8–12 weeks.
3. Physical performance and body composition
Research in trained athletes indicates that 2.5 g/day of TMG over 6 weeks increases strength in bench press and squat by 4–6% versus placebo. The mechanism appears linked to creatine synthesis (TMG donates methyls to produce it).
4. Cognitive function (emerging data)
Observational studies correlate high betaine levels with lower risk of cognitive decline in older adults. The proposed mechanism includes DNA methylation in synaptic plasticity genes, although controlled trials are lacking.
Recommended dosage: how much you need based on your protocol
Optimal dosage depends on whether you're using TMG as a supporting methyl donor or for liver/sports objectives:
Longevity protocols (with NR/NMN):
- 500–1000 mg/day taken alongside NR/NMN
- If you take 300 mg NR (EU maximum dose), start with 500 mg TMG
- If using 500–1000 mg NMN (common protocol outside EU), increase to 1000 mg TMG
Aggressive homocysteine reduction:
- 1500–3000 mg/day divided into 2 doses (studies use up to 6 g with no adverse effects)
- Combine with B vitamins (B6, B9, B12) for synergy
Sports performance:
- 2500 mg/day (dose validated in strength studies)
Timing: TMG absorbs quickly and has no preferred time. You can take it with food to minimise mild digestive discomfort (rare).
How to choose quality TMG (and why few brands include it)
Most NR/NMN brands don't include TMG for two reasons:
- Cost: adding 500 mg of TMG increases manufacturing cost
- Lack of awareness of the methylation cycle: few companies read full studies
When evaluating a NAD+ protocol, look for:
✅ TMG included as standard (500–1000 mg per dose)
✅ Anhydrous betaine (active form, not betaine HCl which is different)
✅ GMP certification (Good Manufacturing Practices)
✅ No fillers (unnecessary maltodextrin, magnesium stearate)
Vitalis Renova+ is the first complete legal NAD+ protocol in the EU. It combines Nicotinamide Riboside (300 mg, maximum permitted dose), trans-resveratrol and pterostilbene (sirtuin activators), TMG 500 mg (mandatory methyl donor with NR), spermidine (autophagy inducer) and hydroxytyrosol (anti-AGEs). Formulated in Spain under GMP certification, with no compromise on bioavailability.
If you prefer standalone TMG (to combine with NR from another brand), verify:
- Purity ≥98% (third-party analysis available)
- Traceable origin (preferably derived from European beetroot)
- No unnecessary additives
Side effects and contraindications
TMG has an excellent safety profile. Studies with doses up to 15 g/day for 6 months report no serious adverse effects.
Mild side effects reported (rare, <5% of users):
- Digestive discomfort (mild nausea, bloating) with doses >3 g/day on an empty stomach
- Slightly sweet body odour (from trimethylamine metabolism, harmless)
Contraindications:
- Trimethylaminuria (rare genetic disorder preventing trimethylamine metabolism)
- Advanced kidney disease (consult your nephrologist, although studies show no issue)
Drug interactions: none clinically relevant reported. TMG does not affect cytochrome P450 or interact with anticoagulants/antihypertensives.
During pregnancy/lactation: no specific studies; best to avoid as a precaution.
Frequently asked questions (FAQ)
Are TMG and anhydrous betaine the same thing?
Yes. TMG (trimethylglycine) and anhydrous betaine are interchangeable names for the same molecule. Do not confuse with betaine HCl (betaine hydrochloride), which is used for stomach acid and does NOT work as a methyl donor.
Can I take TMG without NR/NMN?
Yes. TMG works independently as a methyl donor, homocysteine reducer or liver support. But its critical role in longevity is combined with NAD+ precursors.
How long does it take for homocysteine to drop with TMG?
Studies show measurable reduction within 4–6 weeks with 500–1000 mg/day. Maximum effect is reached in 12 weeks. Order a homocysteine blood test before and after if you want to measure personal impact.
Can TMG substitute for B vitamins in methylation?
It doesn't substitute, it complements. The TMG route and the folate/B12 route work in parallel. For optimal methylation you need both. If you have MTHFR mutation (enzyme that processes folate), TMG is especially important because it bypasses that pathway.
Why do few NR brands include TMG?
Because adding TMG increases manufacturing cost and requires understanding the complete methylation cycle. Most brands copy basic formulas from competitors without reading studies. Serious protocols include TMG as standard.
Does TMG break a fast?
No. TMG contains negligible calories (<1 kcal per 500 mg) and doesn't spike insulin. You can take it during a fasting window without issue.
Conclusion: TMG is not optional in serious NAD+ protocols
If you're investing in Nicotinamide Riboside or NMN to elevate NAD+ and activate sirtuins, ignoring TMG is sabotaging 50% of the benefit. NR works, but it consumes methyls. TMG replenishes them. Without it, you risk raising homocysteine — a marker that increases cardiovascular risk — and stressing the methylation cycle that keeps your DNA, neurotransmitters and detoxification functioning.
The dosage isn't complicated: 500–1000 mg/day alongside your NR/NMN. The cost is minimal. The impact is measurable in homocysteine blood tests within 6–12 weeks. And the additional benefits (liver, performance, cognition) arrive as a bonus track.
Seek out protocols that include TMG as standard. If your current brand doesn't, ask yourself whether they read the full studies or just copied the competitor's label. Your methylation cycle — and your homocysteine — will thank you.
To explore more evidence-based food supplements, review The best supplements for longevity: the guide.
Disclaimer: This information is for educational purposes and does not substitute for professional medical advice. Consult your doctor before starting any protocol, especially if you take medication or have pre-existing conditions. TMG is a food supplement, not a medicine, and is not intended to diagnose, treat, cure or prevent any disease.
