Follistatin vs Spermidine
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
FollistatinAnti-Aging & LongevityCognitive Enhancement
Spermidine- Summary
- Follistatin is an endogenous glycoprotein that acts as a potent inhibitor of myostatin and activin, two proteins that limit muscle growth. By binding and neutralizing myostatin, follistatin removes the primary brake on skeletal muscle hypertrophy, enabling significant muscle growth beyond normal physiological limits. It is distinct from its isoforms Follistatin 315 and Follistatin 344 in tissue distribution and binding affinity.
- 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
- ~3–5 hours (endogenous form)
- ~30–60 minutes, but gut bacteria produce it continuously; supplementation raises tissue levels over weeks
- Admin Route
- IM, SubQ
- Oral
- Research
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- Typical Dose
- 50–100 mcg per injection site
- 1–5 mg
- Frequency
- Every other day or 2–3x per week
- Once daily
- Key Benefits
- Potent myostatin inhibition enabling supraphysiological muscle growth
- Increases skeletal muscle mass and fiber size
- May accelerate recovery from muscle injury
- Potential benefits in muscular dystrophy and sarcopenia
- Synergistic with IGF-1 and growth hormone in anabolic protocols
- Animal studies show dramatic increases in muscle mass
- Reduces muscle fibrosis in dystrophic models
- 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
- Potential for excessive muscle growth if doses are not controlled
- FSH suppression with implications for fertility in women
- Theoretical risk of cardiac hypertrophy with prolonged high-dose use
- Limited human safety data available
- +1 more
- Generally very well tolerated
- Rare: mild GI discomfort at high doses
- May temporarily reduce some gut bacteria species
- Rare: headache at initiation
- Stacks With
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