PubMed
Follistatin induces muscle hypertrophy through satellite cell proliferation and inhibition of both myostatin and activin
Winbanks CE, Wang B, Beyer C, et al. American Journal of Physiology — Endocrinology and Metabolism. 2009
Compare
Follistatin 344 vs TB-500 Fragment
Side-by-side observational reports from PeptIQ users. This compares self-reported patterns — not clinical head-to-head trials.
Last reviewed . By the PeptIQ team.
Observational reporting only — not medical advice. Does not recommend doses, protocols, or treatments.
Follistatin 344
6 community reports
Overall experience
From check-in ratings — separate from side effects logged below. Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Favorable 100% · Mixed 0% · Unfavorable overall 0%
Most reported benefits
Benefits users selected when logging a favorable or mixed check-in.
Recovery
6
Sleep
6
Energy
3
Self-reported dose per injection
Median bucket: 50–100 mcg · Most common: 50–100 mcg
Reports span 50–200 mcg
50–100
4
100–200
2
Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.
Commonly stacked with
TB-500 Fragment
26 community reports
Overall experience
From check-in ratings — separate from side effects logged below. Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Favorable 3% · Mixed 97% · Unfavorable overall 0%
Most reported benefits
Benefits users selected when logging a favorable or mixed check-in.
Recovery
176
Most logged side effects
Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Injection site irritation
171
Self-reported dose per injection
Median bucket: 2+ mg · Most common: 2+ mg
Reports span 1 to ≥ 2 mg (open-ended top bucket)
1–2 mg
59
2+ mg
117
Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.
Commonly stacked with
How repeat users are trending
Among repeat reporters, 79% said they felt similar to their last entry, 21% more positive, and 0% more negative.
Overall, repeat reporters leaned more positive than their previous entry.
Median gap between entries: 188 days · Based on 24 repeat reporters
Sources (8)
Published sources linked on the Follistatin 344 and TB-500 Fragment wiki pages.
- Wiki study page →Source
- Wiki study page →Source
ClinicalTrials.gov
Follistatin / Myostatin inhibition studies on ClinicalTrials.gov
ClinicalTrials.gov. Clinical trial registry. 2024
- Wiki study page →Source
PubMed
Follistatin-derived peptide expression in muscle decreases adipose tissue mass and prevents hepatic steatosis
Sugiyama M, Yamaki A, Furuya M, et al. American Journal of Physiology — Endocrinology and Metabolism. 2010
- Wiki study page →Source
PubMed
Evaluation of follistatin as a therapeutic in models of skeletal muscle atrophy associated with denervation and tenotomy
Sepulveda PV, Bush ED, Bhattacharya A, et al. Scientific Reports. 2015
- Wiki study page →Source
PubMed
The impact of weight loss on fat-free mass, muscle, bone and hematopoiesis health: Implications for emerging pharmacotherapies aiming at fat reduction and lean mass preservation
Stefanakis K, Kokkorakis M, Mantzoros CS. Metabolism: clinical and experimental. 2024
- Wiki study page →Source
PubMed
Thymosin beta4: a multi-functional regenerative peptide (review)
Goldstein AL, Kleinman HK. Ann N Y Acad Sci. 2012
- Wiki study page →Source
PubMed
Thymosin beta 4 and wound healing: a multifunctional peptide
Goldstein AL, Kleinman HK. Expert Opin Biol Ther. 2010
- Wiki study page →Source
PubMed
Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance
Mendias CL, Awan TM. Sports medicine (Auckland, N.Z.). 2026