Follistatin 315 vs DS5
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Sleep Optimization
DS5- Summary
- Follistatin 315 is a splice variant isoform of follistatin produced by alternative mRNA processing. Unlike Follistatin 344 which is tethered to cell surfaces via heparan sulfate proteoglycans, FST-315 circulates freely in the bloodstream and has broader systemic distribution. It is the predominant circulating form and exerts systemic myostatin inhibition as well as FSH suppression, making it relevant to both muscle growth and reproductive endocrinology.
- DS5 is a synthetic variant of the delta sleep-inducing peptide (DSIP), a nonapeptide originally isolated from rabbit cerebrospinal fluid during slow-wave sleep. Like DSIP, DS5 is explored for sleep optimization, stress modulation, and circadian rhythm normalization, with proposed improvements in potency or stability over the parent molecule.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- Estimated 30-60 minutes (peptide degradation)
- Admin Route
- SubQ, IM
- Subcutaneous, Intranasal (research)
- Research
- —
- —
- Typical Dose
- No established human dosing protocol
- 200-500 mcg per dose
- Frequency
- Research use only
- Once nightly
- Key Benefits
- Systemic myostatin inhibition for whole-body muscle growth
- Freely circulating — broader tissue distribution than FST-344
- Strong FSH-suppressive activity useful in certain hormonal protocols
- Potential for greater anabolic effect across multiple muscle groups simultaneously
- May be more relevant to reproductive endocrinology applications
- Studied in gene therapy approaches for muscular dystrophy
- Promotes delta-wave (deep) sleep and improves sleep quality
- May reduce sleep onset latency
- HPA axis modulation for stress reduction
- Non-addictive sleep support without tolerance development
- Potential circadian rhythm normalization
- Explored for insomnia, chronic stress, and PTSD-related sleep disturbance
- Side Effects
- Systemic FSH suppression — significant concern for fertility
- Greater potential for off-target effects vs FST-344 due to systemic distribution
- Limited human safety data
- Potential cardiac hypertrophy with prolonged high-dose exposure
- Generally well-tolerated in research subjects
- Possible morning grogginess at higher doses
- Mild blood pressure fluctuations reported with DSIP
- Limited human safety data for DS5 specifically
- Stacks With
- —
- —