Robin's Short Version

Get your Omega-3 Index checked. Target range: 8–11%.
If you supplement, take real fish oil—marine EPA+DHA—not a plant-based capsule.
Flax, chia, and walnut oil are not fish oil substitutes.

These days, it's a whole-family thing—my kids get an EPA/DHA supplement from Metagenics too.

Not because it's trendy—it's not. If anything, fish oil might be the most argued-about supplement on the shelf. Half the wellness world calls it snake oil. The other half won't skip a day.

I've read the actual trials. My take: the confusion isn't really about whether omega-3s work. It's about which ones, how much, and whether you're actually getting them into your blood.

If you've never had your Omega-3 Index checked, it's one of 80+ biomarkers on my Longevity Labs panel—and it's one of the first things I look at. Check yours →

This week: what that number actually means, why your brain (about 60% fat) needs it, and exactly what to take—and skip—if you're going to supplement.

What to know: Real omega-3s aren't optional — they're structural.

The old assumption vs. the new reality

❌ The old assumption: any omega-3 source counts—flax, chia, walnut, algae, fish, doesn't matter.

✅ The new reality: your body barely converts plant ALA into usable EPA and DHA—under 8% converts to EPA, under 4% to DHA.¹ A tablespoon of flaxseed oil is not a fish oil substitute.

❝ Nearly 95% of Americans fall into the "high risk" category on the Omega-3 Index.²

Heart

Pooled across 13 trials and 127,000+ people, marine omega-3s lowered risk of heart attack, coronary death, and cardiovascular death by roughly 7–8%.³ A high-dose purified EPA trial cut cardiovascular events 25% in high-risk patients.⁴ A lower, general-population dose showed no overall benefit—except in people who ate little fish to begin with, where risk dropped 19%.⁵ The people who benefit most are the people who start out most deficient.

Brain

DHA is a core structural fat in neurons. In the Women's Health Initiative MRI study, women with the lowest Omega-3 Index had measurably smaller brain and memory-center volume than women with higher levels.⁶

Mood & hormones

EPA specifically (not DHA) shows real antidepressant-level effects—but only in formulas where EPA makes up 60%+ of total EPA+DHA, at 200–2,200mg/day of EPA.⁷ Low-EPA formulas showed no benefit. The same EPA-forward dosing helps in pregnancy and postpartum depression specifically.⁸ In PCOS, a meta-analysis of 10 trials (N=610) found omega-3 supplementation significantly lowered total testosterone and raised SHBG.⁹

What to do: Test first. Then choose real fish oil, dosed right.

1️⃣ Get your Omega-3 Index tested—then know your number.

It's a simple blood test measuring EPA+DHA in your red blood cells, which reflects roughly the last 3–4 months, not just yesterday's dinner. It's part of my Longevity Labs panel. Retest annually, or 3–4 months after changing your dose.

Under 4%: high risk (most Americans land here)
4–8%: intermediate
8–11%: target range

2️⃣ Skip plant-based omega-3 if fish oil is the actual goal.

Flax, chia, and walnut oil supply ALA, which converts to EPA/DHA at under 8%. If you're avoiding fish entirely, algae oil is the real exception—it supplies preformed DHA directly, the way fish do.

3️⃣ Choose a real, tested fish oil.

Look for triglyceride form, which absorbs better than the cheaper ethyl ester form,¹⁰ molecular distillation to remove mercury and heavy metals, and third-party testing for purity. This is why I take Parsley's Mega Omega 3—sourced from sardine, anchovy, and mackerel, and tested batch by batch.

4️⃣ Dose it consistently.

1–2g/day combined EPA+DHA is the range most trials use. Two softgels of Mega Omega 3 gives you 860mg EPA + 580mg DHA (1.4g total) daily.

👉 One caveat: risk of Atrial Fibrillation (AFib)—a specific heart arrhythmia—rises with dose. Trials above 1g/day showed a higher relative risk than those at 1g/day or under, and the highest-dose cardiology trials (near 4g/day) showed the strongest signal.¹¹ At standard supplement doses, absolute risk is low—but flag it with your doctor if AFib runs in your history.

The goal: real fish oil, real dose, retested to confirm it's actually working—not a guess.

The Loving Longevity (formerly Momgevity) Files

I'm re-titling "Momgevity" because someone reached out to me on Instagram and said they trademarked "Momgevity." I'll be honest, I'm annoyed! This term isn't well known. If you're going to trademark something, use it—and if you aren't, let it go so someone else can!

Anyway… rant over.

This week I'm getting back into gear after two weeks in Spain. It felt really good to disrupt my routine. Sometimes you have to miss something a little to appreciate it, and exposing yourself to new ways of being is essential to avoid life getting stale.

One of the workouts I did in Ibiza was called Primal Moves—a full-body workout that combines parts of HIIT, yoga, and capoeira, the Brazilian dance-meets-martial-arts practice. It's now in LA too—if you're there, check it out and let me know if you like it. It forced me to use my body, and my brain, in very new ways, which was like a light going on for muscles I rarely touch or engage. It made me think about what other parts of myself I haven't been using, or that are available to turn on if I try something new.

I'm in a moment in life when I'm being asked to change, and I'm not alone. So many friends, patients, and acquaintances are in a similar spot—as if the universe is collectively putting a boot on our butts to move, shift, and grow, whether we like it or not.

So I'm leaning in. I've got a list of books to read, I'm signing up for a pottery class, and I have a list of retreats on the docket—I plan to attend at least two this fall. I tend to resist change, so consciously I'm embracing it with courage and love instead of resistance. I find doing little things, like a new workout, creates just a little plasticity—that perfect BDNF (brain-derived neurotrophic factor) boost—in a way that opens more doors from there.

Longevity isn't possible without plasticity, flexibility, and a willingness to change. Static equals brittle. It's one reason I love yoga—it forces me to stretch my connective tissue in ways I don't in walking, cardio, or weights. It initiates physical flexibility, advancing my flexibility of thought off the mat. So if you're finding yourself feeling stale or stuck this summer, find a new way to move—literally. As you move your body, you move your mind, and your life can change, for the better, if you let it.

One more thing…

Your Omega-3 Index is one of 80+ biomarkers on my Longevity Labs panel—book yours here →. Want to start today without waiting on labs? This is the fish oil I take and recommend: Parsley's Mega Omega 3 →.

References

Lipids in Health and Disease, 2009.
OmegaQuant data.
Journal of the American Heart Association, 2019.
New England Journal of Medicine, 2019—REDUCE-IT.
New England Journal of Medicine, 2019—VITAL.
Alzheimer's & Dementia, 2021.
Journal of Clinical Psychiatry, 2011.
Translational Psychiatry, 2020.
Annals of Palliative Medicine, 2021.
Prostaglandins, Leukotrienes and Essential Fatty Acids, 2010.
Circulation, 2021.

Originally published in the Off Script newsletter. Join Robin’s readers for weekly functional medicine insights.

As always, this newsletter is for informational and educational purposes only and is not intended as medical advice. Always consult your healthcare provider before making any health decisions or changes to your treatment plan.