Betaine (TMG / Trimethylglycine) vs Hydrolyzed Cluster Dextrin

Mechanism

Betaine (trimethylglycine) serves as a methyl donor in the betaine-homocysteine methyltransferase (BHMT) reaction, converting homocysteine to methionine — this is the alternative methyl cycle pathway (parallel to the folate-dependent methionine synthase pathway). It functions as an osmolyte, protecting cells from osmotic stress by maintaining intracellular water balance (critical for kidney medulla and muscle cells). Athletic performance benefits likely derive from enhanced creatine synthesis (methyl donation), improved power output via osmotic cell protection, and reduced homocysteine-mediated vascular impairment.

Standard Dosing

2500mg (2.5g) daily

Timing

Split AM/PM or pre-workout. When used as methyl donor with NMN/NR, take with the NAD+ precursor.

Cycle Duration

ongoing

Side Effects

• Fishy body odor (TMA production)
• GI upset/diarrhea
• Nausea
• Methionine elevation (theoretical concern with chronic high-dose use in cancer context)

Contraindications

• Trimethylaminuria (fish odor syndrome — impaired TMA metabolism)
• Homocystinuria (under medical management — betaine is actually used therapeutically here, but dosing requires physician oversight)

Best Stacking Partners

Mechanism

Low-osmolality cyclic glucose polymer that supports gastric emptying and intra-session carbohydrate delivery with less GI burden than many simpler carbs.

Contraindications

• Use cautiously in clients with poor glucose control