Krill Oil vs Selenium (Selenomethionine)

Omega / Fatty Acid vs Mineral · evidence-backed comparison

Quick take
  • Krill Oil has the broader effect profile across the 9 effect categories.
  • Selenium (Selenomethionine) is cheaper per serving ($0.10 vs $0.80).
  • Krill Oil has a slightly cleaner safety profile.

Side-by-side traits

TraitKrill OilSelenium (Selenomethionine)
Category
Omega / Fatty AcidMineral
Active compound
Phospholipid-bound EPA/DHA + astaxanthinSelenomethionine
Form available
SoftgelCapsule, Tablet
Source
marinesynthetic
Typical dose
1–2 g daily (≈ 0.3 g EPA+DHA)100–200 mcg daily
Dose range
1–2 g100–200 mcg
Loading protocol
Best taken with
with foodwith food
Best time of day
anyany
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)Very High (5/5)
Onset time
Cumulative: 4–12 weeksCumulative: 4–12 weeks
Half-life
~252 days (long body store)
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Low (2/5)
Muscle / strength
Low (2/5)Very Low (1/5)
Physical energy
Low (2/5)Low (2/5)
Focus / cognition
Moderate (3/5)Very Low (1/5)
Mood / stress
Moderate (3/5)Low (2/5)
Sleep quality
Low (2/5)Very Low (1/5)
Immunity
Low (2/5)Moderate (3/5)
Recovery
Post-exercise recovery support.
Moderate (3/5)Low (2/5)
Longevity / healthspan
High (4/5)Moderate (3/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
High (4/5)Moderate (3/5)
Price per serving
Approximate USD per typical daily dose.
$0.80$0.10
Vegan friendly
NoYes
Gluten free
YesYes
3rd-party tested
YesYes

About Krill Oil

Phospholipid-bound omega-3s with included astaxanthin. Better absorbed per gram than fish oil but ~3× the price for same EPA/DHA.

Active compound: Phospholipid-bound EPA/DHA + astaxanthin
Forms: Softgel
Onset: Cumulative: 4–12 weeks
heartbrainphospholipidastaxanthin

About Selenium (Selenomethionine)

Cofactor for glutathione peroxidase and thyroid hormone activation. Two Brazil nuts per day already meet requirements; toxicity above 400 mcg.

Active compound: Selenomethionine
Forms: Capsule, Tablet
Onset: Cumulative: 4–12 weeks
thyroidantioxidantfertilityglutathione

Krill Oil safety

Common side effects:

  • No fishy burps
  • Mild GI upset (rare)

Avoid if:

  • Crustacean allergy
  • Bleeding disorders

Drug interactions:

  • Anticoagulants

Selenium (Selenomethionine) safety

Common side effects:

  • Selenosis (>400 mcg/day): hair loss, garlic breath, brittle nails

Avoid if:

  • Already eating Brazil nuts daily

Drug interactions:

  • Anticoagulants

Common uses

  • Heart health
  • Joint inflammation
  • Eye health

Stacks well with: Vitamin D3

Common uses

  • Thyroid support
  • Hashimoto's
  • Antioxidant

Stacks well with: Iodine (Potassium Iodide)

Medical disclaimer

SupplementDuel is for educational purposes only and is not medical advice. Consult a physician before starting, stopping, or combining supplements — especially if you are pregnant, breastfeeding, take prescription medication, or have a chronic condition.