This Week at Peak Human: Survodutide's New Liver-Fat Data, and Does Nattokinase Actually Work?

A note from Dr. Goel

This week's note is less a single deep dive and more a quick tour of what's new at peakhuman.ai. The one I'd flag first: our Survodutide intervention page just got rebuilt around new Phase 3 liver-fat data — the best numbers I've seen yet from a GLP-1/glucagon peptide. We also published fresh evidence reviews this week on nattokinase, seed oils, the endothelial glycocalyx, and seafood safety in pregnancy. Here's what changed, and what the data actually shows.

— Dr. Sanjeev Goel

What's new at Peak Human this week

Five updates from the past seven days — starting with the one I'd flag first.

1. Survodutide — the clearest liver-fat data yet for a GLP-1/glucagon peptide

We rebuilt our Survodutide intervention page this week around the newest Phase 3 data. Survodutide is an investigational, once-weekly dual GLP-1/glucagon receptor agonist — not approved, and not something Peak Human sells. In the 76-week SYNCHRONIZE-1 trial (NEJM, 2026; 725 adults with obesity, no diabetes), the 6.0 mg dose produced up to 16.6% weight loss versus roughly 3.2% on placebo, with an MRI substudy showing about a 34% relative reduction in visceral fat and about 63% in liver fat — the glucagon component's signature effect. In the follow-on SYNCHRONIZE-MASLD trial (Nature Medicine, 2026), 84% of treated patients reached at least a 30% liver-fat reduction versus 24% on placebo. The trade-off: GI side effects drove treatment discontinuation in up to roughly one in five participants during dose escalation.

2. Does nattokinase actually work? A new evidence review

Nattokinase gets credited online with dramatic plaque-reversal claims. The rigorous evidence doesn't back that up: in the NAPS trial, 265 adults were randomized to nattokinase or placebo and followed for a median of three years, tracking carotid intima-media thickness and arterial stiffness — and the rate of change didn't differ between groups. The dramatic numbers you'll see cited elsewhere (a 21.7% drop in carotid thickness, 36% plaque reduction) come from a 12-month study with no control group at all.

3. Are seed oils actually bad for you?

The seed-oil panic doesn't hold up well against trial data. A pooled analysis of 30 randomized trials (1,377 participants) found that raising linoleic acid intake didn't move inflammatory markers. In the JAMA Internal Medicine (2025) analysis of three long-running cohorts — 221,054 adults followed up to 33 years — swapping just 10 g of butter a day for plant oils tracked with roughly 17% lower all-cause mortality. A separate pooling of nearly 70,000 people found higher blood linoleic acid linked to 22% lower cardiovascular death.

4. The endothelial glycocalyx — do supplements like Arterosil actually work?

The glycocalyx is the thin layer lining your blood vessels that senses flow and triggers nitric-oxide release — strip its heparan sulfate and that signal disappears. Rhamnan sulfate, the seaweed-derived ingredient in Arterosil, has real preclinical signal (reduced endothelial inflammation and leukocyte adhesion in lab and animal models) but no completed, published randomized controlled trial in humans — what exists so far is small, open-label, or retrospective.

5. How much fish is safe in pregnancy?

Mercury fear keeps many pregnant women away from fish entirely — but the ALSPAC cohort of nearly 12,000 UK pregnancies found the opposite risk is larger: mothers who ate no seafood during pregnancy had 48% higher odds of a child in the lowest verbal-IQ quartile at age 8, with no evidence of cognitive harm at the mercury levels seen in women who did eat fish.

My take: Survodutide is the one I'd watch longest. The liver-fat numbers are the best I've seen from any incretin-class peptide, and that matters specifically for metabolic dysfunction-associated liver disease. But it's investigational, unapproved, and the GI tolerability isn't trivial — pushing roughly a fifth of trial participants to stop. This is a research update, not a recommendation. If you're curious about GLP-1/glucagon therapy, that's a conversation for your physician, not a supplement order.

Longevity news worth your minute

Pharmacogenomics, now live on our Genetic Testing page: in the randomized PREPARE trial (The Lancet), a 12-gene pharmacogenomic panel cut clinically relevant adverse drug reactions by about 30% — from 28% to 21% of patients.

The dropout column matters: across Survodutide's Phase 3 program, GI side effects drove discontinuation in up to roughly 20% of participants during dose escalation — a reminder that weight-loss headlines rarely lead with tolerability.

⚕️ Important disclaimer

This newsletter is for educational purposes only and is not medical advice. Compounds discussed may be investigational and not FDA-approved. Nothing here is a recommendation to start, stop, or change any treatment. Peptide and metabolic therapies carry real risks and should only be used under qualified medical supervision. Always consult your physician before making health decisions.