Glycine vs Krill Oil

Sleep vs Omega / Fatty Acid · evidence-backed comparison

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

Side-by-side traits

TraitGlycineKrill Oil
Category
SleepOmega / Fatty Acid
Active compound
GlycinePhospholipid-bound EPA/DHA + astaxanthin
Form available
Powder, CapsuleSoftgel
Source
syntheticmarine
Typical dose
3 g before bed1–2 g daily (≈ 0.3 g EPA+DHA)
Dose range
3–5 g1–2 g
Loading protocol
Best taken with
water, 30 min before bedwith food
Best time of day
eveningany
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)Very High (5/5)
Onset time
Acute: 30–60 minCumulative: 4–12 weeks
Half-life
~1 hour
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Low (2/5)Moderate (3/5)
Muscle / strength
Low (2/5)Low (2/5)
Physical energy
Very Low (1/5)Low (2/5)
Focus / cognition
Low (2/5)Moderate (3/5)
Mood / stress
Moderate (3/5)Moderate (3/5)
Sleep quality
High (4/5)Low (2/5)
Immunity
Very Low (1/5)Low (2/5)
Recovery
Post-exercise recovery support.
Low (2/5)Moderate (3/5)
Longevity / healthspan
Moderate (3/5)High (4/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
Very High (5/5)High (4/5)
Price per serving
Approximate USD per typical daily dose.
$0.10$0.80
Vegan friendly
YesNo
Gluten free
YesYes
3rd-party tested
YesYes

About Glycine

Sweet-tasting amino that lowers core body temperature for deeper sleep. Cheap, well-tolerated, and especially useful with magnesium glycinate.

Active compound: Glycine
Forms: Powder, Capsule
Onset: Acute: 30–60 min
sleep-qualitydeep-sleepamino-acidthermal-regulation

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

Glycine safety

Common side effects:

  • Generally none

Avoid if:

  • Clozapine therapy

Drug interactions:

  • Clozapine

Krill Oil safety

Common side effects:

  • No fishy burps
  • Mild GI upset (rare)

Avoid if:

  • Crustacean allergy
  • Bleeding disorders

Drug interactions:

  • Anticoagulants

Common uses

  • Deep sleep
  • Sleep quality
  • Collagen synthesis

Stacks well with: Magnesium Glycinate, Melatonin

Common uses

  • Heart health
  • Joint inflammation
  • Eye health

Stacks well with: Vitamin D3

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.