Omega-3 (EPA + DHA)
High-dose EPA+DHA produces a small but consistent BP reduction. Dose-dependent — small doses don't move the needle.
Miller et al. 2014 meta-analysis (70 RCTs) found omega-3 supplementation produced a small reduction in BP, with effect significantly larger at higher doses (≥2g/day EPA+DHA combined).
Most omega-3 trials use doses that are too low to move BP meaningfully. The 2014 meta-analysis stratified by dose and found a clear pattern: small doses (typical drugstore softgels) had a small or insignificant effect; larger doses (≥2g combined EPA+DHA) had a real one.
This is the key practical insight from this literature. Many people who say "I tried omega-3 for BP and it didn't help" took ~500mg. They didn't actually test it.
Form and quality
Triglyceride-form fish oil is better absorbed than ethyl-ester form. Third-party tested products (USP, NSF, IFOS) are worth the markup — fish oil quality varies more than most consumers realize.
Mechanism
The proposed mechanism is improved endothelial function, reduced inflammatory tone, and modest improvements in arterial stiffness. The mechanism is multifactorial, which is part of why the effect size per individual is hard to predict.
How it sits in the stack
Tier 1 (Week 1) supplement. Adherence is usually high because the dosing is once daily with food.
What the app does
Tracks adherence and timing. Dose calibration lives in the app, where your dietary fish intake is factored in (high baseline fish eaters need less supplementation).