What kind of interaction is it?

Caution: an interaction that may reduce efficacy or raise side-effect risk and warrants monitoring.

Is this interaction backed by published research?

Yes. NutriStack lists 1 citation row for the Fish Oil + Trimethylglycine pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Supplement × Supplement·a caution·Moderate evidence

Fish Oil + Trimethylglycine

Q: Can I take Fish Oil and Trimethylglycine together?

Possibly, but with caution. Fish Oil and Trimethylglycine have a documented caution-tier interaction. High-dose betaine can modestly raise LDL cholesterol and triglycerides in some people. Pairing with omega-3 fish oil, which tends to lower triglycerides, may help offset the lipid effect, but lipids should still be monitored.

Q: How does this affect a NutriStack Stack Score?

-5 to your Stack Score per scored caution row.

Caution Moderate evidence

High-dose betaine can modestly raise LDL cholesterol and triglycerides in some people. Pairing with omega-3 fish oil, which tends to lower triglycerides, may help offset the lipid effect, but lipids should still be monitored.

Supplement × Supplement

Open the interaction checker → Read the methodology

From the database

What the row says.

Every entry follows the same shape: what is happening, the mechanism, and the recommendation.

Substances

Fish Oil and Trimethylglycine

Pair type

Caution

Evidence

Moderate

Source citations

Scope

Supplement × Supplement

Last verified

June 4, 2026

CautionModerate evidence

What is happening. High-dose betaine can modestly raise LDL cholesterol and triglycerides in some people. Pairing with omega-3 fish oil, which tends to lower triglycerides, may help offset the lipid effect, but lipids should still be monitored.

Mechanism. Betaine supplementation has been associated with dose-dependent increases in total and LDL cholesterol; omega-3 fatty acids reduce hepatic VLDL/triglyceride output through separate pathways.

Recommendation. If using higher TMG doses, check a lipid panel periodically. Fish oil is a reasonable co-supplement for those concerned about triglycerides, but it does not guarantee neutralization of the LDL effect.

Stack Score

How it moves the number.

Effect on the composite score

If both Fish Oil and Trimethylglycine are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).

The full algorithm, the clamping rules, and four worked stacks are at /methodology/stack-score.

Sources

Sources, by evidence tier.

Every claim on this page is cited. PMIDs link straight to PubMed.

Reference material

1Olthof MR, et al. Betaine supplementation and plasma cholesterol in healthy volunteers. Am J Clin Nutr. 2005.Needs sourceNo link

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