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ToolsCompareP21 vs Enclomiphene

P21 vs Enclomiphene

Side-by-side comparison of key properties, dosing, and research.

Cognitive EnhancementAnti-Aging & Longevity
P21
GLP-1 / Weight Loss Agonists
Enclomiphene
Summary
P21 is a synthetic peptide derived from CNTF (ciliary neurotrophic factor) that promotes hippocampal neurogenesis, enhances memory and spatial learning, and may reduce amyloid-beta pathology. It is used as a neurogenic and cognitive enhancer with potential anti-Alzheimer's applications.
Enclomiphene is the trans-isomer of clomiphene citrate, a selective estrogen receptor modulator (SERM) that stimulates endogenous testosterone production by blocking estrogen negative feedback on the hypothalamus and pituitary. Unlike TRT, it restores testosterone while preserving or increasing sperm production and testicular volume.
Half-Life
Not well characterized; likely short, but neurogenic effects persist long after administration
5-7 days (long half-life; accumulates)
Admin Route
SubQ, Intranasal
Oral
Research
Typical Dose
100–500 mcg
12.5-25 mg per day
Frequency
Once daily
Once daily or every other day
Key Benefits
  • Promotes hippocampal neurogenesis
  • Enhances spatial memory and learning
  • Increases BDNF expression
  • Reduces amyloid-beta plaque formation (animal models)
  • Anti-tau pathology potential
  • Cognitive enhancement without stimulant effects
  • Potential therapeutic for Alzheimer's and cognitive aging
  • Restores testosterone to normal range without exogenous androgen administration
  • Preserves or increases sperm production and fertility
  • Maintains testicular volume (unlike TRT which causes testicular atrophy)
  • LH and FSH levels rise, indicating intact HPG axis function
  • Option for hypogonadal men desiring fertility
  • Oral administration (no injection required)
Side Effects
  • Generally well tolerated in animal studies
  • Limited human clinical data
  • Injection site reactions
  • Potential mild fatigue at initiation
  • Visual disturbances (rare but class-related SERM effect)
  • Mood changes or irritability
  • Hot flashes
  • Elevated estradiol in some users
  • +2 more
Stacks With