Palmitoyl Dipeptide-6 vs Spermidine
Side-by-side comparison of key properties, dosing, and research.
Skin & CosmeticAnti-Aging & Longevity
Palmitoyl Dipeptide-6Anti-Aging & LongevityCognitive Enhancement
Spermidine- Summary
- Palmitoyl Dipeptide-6 is a synthetic dipeptide (lysine-threonine) with a palmitoyl fatty acid tail, designed to penetrate the skin barrier and stimulate the extracellular matrix components essential for skin firmness. It activates fibronectin and type IV collagen synthesis, improving skin density and firmness particularly in mature or sagging skin.
- Spermidine is a naturally occurring polyamine found in all living cells, with exceptionally high concentrations in wheat germ, aged cheese, and human sperm. It is the most studied autophagy-inducing dietary compound, shown to extend lifespan across multiple species and reduce cardiovascular and cognitive aging.
- Half-Life
- Not applicable (topical)
- ~30–60 minutes, but gut bacteria produce it continuously; supplementation raises tissue levels over weeks
- Admin Route
- Topical
- Oral
- Research
- —
- —
- Typical Dose
- 0.005–0.05% in formulation
- 1–5 mg
- Frequency
- Once or twice daily
- Once daily
- Key Benefits
- Increases skin firmness and density
- Stimulates fibronectin and collagen IV production
- Strengthens the dermal-epidermal junction
- Reduces skin sagging in mature skin
- Improves skin texture and smoothness
- Supports extracellular matrix integrity
- Induces autophagy — cellular self-cleaning
- Extends lifespan in yeast, flies, worms, and mice
- Reduces cardiovascular aging and arterial stiffness
- Reduces all-cause mortality (human epidemiological data)
- Neuroprotective: reduces amyloid and tau pathology
- Promotes hair growth (anagen phase activation)
- Reduces age-related immune decline
- Improves memory in aging models
- Side Effects
- Generally well-tolerated
- Rare mild skin irritation in sensitive individuals
- No known systemic effects at cosmetic concentrations
- Generally very well tolerated
- Rare: mild GI discomfort at high doses
- May temporarily reduce some gut bacteria species
- Rare: headache at initiation
- Stacks With
- —
- —