Krill Oil

Supplements · Fatty Acids · Supplement, Typed Supps

An omega-3 oil from tiny Antarctic crustaceans, often marketed as better-absorbed than fish oil, though the actual proof of that advantage is mixed.

Stage by stage

Intake (Softgel capsule): Taken as krill oil, ideally with a fat-containing meal.
Small intestine (Absorbed): EPA/DHA absorbed via phospholipid and fat digestion pathways.
Bloodstream (Circulates): Carried to tissues throughout the body.
Cell membranes (Cardiovascular & inflammatory tissue): Incorporated into cell membranes, supporting cardiovascular and anti-inflammatory function similarly to fish oil.

What the evidence supports

Raising omega-3 index (blood EPA/DHA levels) — moderate evidence. Controlled trials show krill oil reliably raises the omega-3 index, though head-to-head trials comparing it to standard fish oil have produced mixed results on whether it's actually absorbed better — some acute studies favor krill oil's phospholipid-bound omega-3s, but this hasn't consistently translated into a proven long-term absorption advantage.
Superior absorption compared to fish oil due to phospholipid binding — limited evidence. The phospholipid-vs-triglyceride bioavailability theory is scientifically plausible and shown in some pharmacokinetic studies, but a review of the overall literature found the studies have not reached a clear, consistent conclusion that krill oil is better absorbed than fish oil in practice.
Evidence on General safety and shellfish allergy risk — moderate evidence. Krill oil is derived from a crustacean, so it carries a real allergy risk for people with shellfish allergies, distinct from and in addition to the general mild bleeding-risk caution that applies to any omega-3 supplement at high doses.

Typical dose

500–1,000 mg of krill oil daily, providing roughly 150–300 mg of combined EPA and DHA — a lower absolute omega-3 dose per capsule than most fish oil products.

Upper limit: No established UL for krill oil specifically; the FDA advises no more than about 3 g/day combined EPA and DHA from all sources, including up to 2 g/day from supplements.

Timing

Take with a fat-containing meal to aid absorption.

Time to effect

Weeks: Blood omega-3 index rises measurably over several weeks of consistent daily use.

Common myth

“Krill oil is proven to absorb better than fish oil.” In reality: The phospholipid-bound theory is biologically plausible and shown in some acute studies, but a review of the comparative research found no consistent conclusion that krill oil is better absorbed than fish oil in practice.