LDL Particle Size

Lipids marker

LDL Size

LDL Particle Size

Category: Lipids
Unit: nm

Mean diameter of LDL particles. Pattern A (large buoyant, >20.5 nm) is less atherogenic; Pattern B (small dense, <20.5 nm) is associated with increased cardiovascular risk.

PED Notes

AAS shift LDL toward small dense Pattern B particles, increasing atherogenicity even when total LDL-C is not dramatically elevated. Oral AAS (stanozolol, oxandrolone) cause the most pronounced shift to small dense LDL. Insulin resistance from GH/insulin use compounds this shift. High triglycerides correlate with smaller LDL. Pattern B + elevated LDL-P is the most concerning combination.

When low

Understanding LDL Size:

  • Pattern A (>20.5 nm) = large buoyant LDL → lower cardiovascular risk
  • Pattern B (<20.5 nm) = small dense LDL → higher cardiovascular risk
  • Small dense LDL penetrates arterial walls more easily and is more susceptible to oxidation

If Small Dense (Pattern B):

  • Reduce refined carbohydrates and sugar (primary dietary driver of small dense LDL)
  • Omega-3 fatty acids shift LDL toward larger particles

Supplements:

  • Omega-3 (EPA/DHA) -- 2-4g/day (shifts LDL to Pattern A)
  • Niacin -- 500-1000mg/day extended-release (increases LDL size; use with caution, monitor liver)
  • Citrus Bergamot -- 500mg 2x/day

Lifestyle:

  • Reduce refined carbohydrates and sugar intake
  • Regular aerobic exercise (most effective for shifting to Pattern A)
  • If on oral AAS and Pattern B persists, consider discontinuing orals

Pharmacological options:

  • Fenofibrate -- 145-200mg/day; PPAR-alpha agonist; shifts LDL toward larger Pattern A particles while lowering triglycerides (the main dietary driver of small dense LDL)
  • Pemafibrate -- 0.2mg 2x/day where available; selective PPAR-alpha modulator with cleaner safety profile than fenofibrate
  • Semaglutide / Tirzepatide -- GLP-1 agonists; improve LDL size indirectly via insulin sensitivity and triglyceride reduction; particularly useful for GH/MK-677 users with concurrent metabolic dysfunction
  • Statins (rosuvastatin 5-20mg/day) primarily reduce particle number rather than changing size, but the combined ApoB/LDL-P reduction usually outweighs any size concern; see LDL and ApoB markers for full protocol
  • All prescription items require physician oversight

History Chart

Reading History

Frequently Asked Questions

Reference Ranges

Standard Range

20.5 - 23 nm

VitalMetrics Range

19.8 - 23 nm

Statistics