Peptide

Follistatin 344

Also known as

FST-344 · FS-344 · FS344 · FST344 · Follistatin-344 · Follistatin · FST-344 (precursor → FS-315) · FS344 / FS315 isoform family · AAV1-FS344 (gene-therapy context) · recombinant follistatin (research peptide)

Community talk. May contain inaccuracies. Not medical advice. Not a protocol. Not for human or animal use.

What it is

Identity	A protein that binds myostatin and activins, discussed for muscle building. The 344-amino-acid precursor becomes FS-315 after its signal sequence is removed.
Different products	Ordinary protein vials, modified long-acting proteins and follistatin gene delivery are different things. Their amounts and claimed persistence are not interchangeable.

Notes

Follistatin 344 attracts muscle-building interest because follistatin binds growth-limiting signals such as myostatin. Injectable-product reports range from fuller muscles and stronger pumps to no change, fatigue or painful reactions. The central complication is that a protein vial, a modified long-acting product and follistatin gene therapy are different things.

344 names the precursor; 315 is the processed protein. Follistatin is a glycoprotein, larger than the short peptides usually discussed in gym communities. Removing the precursor's 29-amino-acid signal sequence leaves FS-315. It binds activins as well as myostatin, so the popular muscle-brake explanation leaves out other biological effects. R&D Systems — Recombinant Human Follistatin 315 aa 30–344 datasheet (Official context · Accessed 2026-09-30)

Protein injection and gene delivery cannot share one dose chart. Community protein-vial logs use micrograms. Gene delivery supplies instructions for cells to make follistatin; it does not simply inject the same protein. FLGR-242, plasmid products and oral yolk-derived supplements also need their own identities. Their amounts or claimed persistence cannot be pasted onto an ordinary FS-344 vial. r/NTNPerformance — Follistatin-344 peptide guide (Community guide · Accessed 2026-09-30)

Engineered protein studies do not measure an ordinary vial's half-life. FST315-Fc variants were deliberately changed to prolong exposure and were studied in mouse disease models. Those constructs, viral vectors, plasmids and experimental mRNA delivery cannot supply interchangeable human clearance or cycle values. Datta-Mannan et al. — An engineered human follistatin variant (Animal context · Accessed 2026-09-30) · r/NTNPerformance — Follistatin-344 peptide guide (Community guide · Accessed 2026-09-30)

Source context — R&D Systems — Recombinant Human Follistatin 315 aa 30–344 datasheet: Commercial laboratory-reagent documentation supports identity context, not human effectiveness or retail-vial equivalence. Preparation/storage specifications are not transferred to community products or reproduced as instructions.

Source context — r/NTNPerformance — Follistatin-344 peptide guide: Community/practitioner synthesis, not firsthand testing or a cited human dose-finding trial. Prescriptive start/cycle and axis-reset assertions are qualified rather than adopted. Author's commercial affiliations not independently established.

Source context — Datta-Mannan et al. — An engineered human follistatin variant: Abstract only, no primary full-text PK table inspected. No numeric animal half-life placed on card. Engineered construct and species are not a community human protein-vial measurement; addendum full text unreviewed.

What people notice

Fullness and pumps	Some describe fuller muscles, stronger pumps or easier recovery between sets. One account also used BPC-157; another involved harder training and a better diet.
No change	One Eroids author reported no body-composition or measurement change after 20 days at 100 mcg/day, alongside testosterone, deca and HCG.
Unwanted experiences	Fatigue and painful local reactions occur. One person also using BPC-157 stopped a planned six-week run a week early because of hand-joint pain.

Notes

Fullness, pumps and easier recovery between sets. One Reddit account describes those changes during a planned six-week run with BPC-157, but also hand-joint pain. Another five-week account describes modest fullness while training harder and improving diet. Neither establishes new muscle tissue or isolates follistatin's contribution. r/Biohacking — Follistatin-344 pumps, BPC co-use and hand pain (Personal report · Accessed 2026-09-30) · r/Peptides — Has anyone here tried follistatin, with what results? (Personal report · Accessed 2026-09-30)

No change is part of the record. An Eroids author reported no body-composition or measurement change after 20 days at 100 mcg/day, despite concurrent testosterone, deca and HCG. A nonresponse does not prove a fake product or justify a higher amount. Eroids — giardap's Follistatin-344 cycle (Personal report · Accessed 2026-09-30)

Pain, swelling, fatigue and joint complaints. Logs describe painful local reactions and tiredness; the recent user also taking BPC-157 stopped a week early because of hand-joint pain. Original notes also mention flu-like malaise, headache, appetite or sleep changes, nausea and dizziness. These reports do not identify incidence, infection or which ingredient caused a symptom. r/Biohacking — Follistatin-344 pumps, BPC co-use and hand pain (Personal report · Accessed 2026-09-30)

Source context — r/Biohacking — Follistatin-344 pumps, BPC co-use and hand pain: Retrospective report about last year, without route or amount; six-week wording plus a week-early stop does not establish actual exposure duration. BPC co-use cannot establish connective-tissue protection.

Source context — r/Peptides — Has anyone here tried follistatin, with what results?: One-vial versus weekly-cost wording ambiguous, route unspecified, amount per injection unresolved. Self-reported normal bloodwork is not a safety study. Exact dates not exposed by opened relative timestamps; deleted and collapsed branches unavailable.

Source context — Eroids — giardap's Follistatin-344 cycle: Anonymous retrospective self-report, untested product and concurrent PEDs. No route given. Marketplace-adjacent forum; replies' fake-product explanations are unverified.

Doses people talk about

Daily under-skin (SubQ) charts	100–200 mcg total/day is repeated in a guide, including 100 mcg/day for 10 days. Separate older charts give 250 or 200–300 mcg/day; these are not validated benefit bands.
Into-muscle (IM), training days	50 or 100 mcg before workouts appears. The 100-mcg log split that total between both sides of the trained muscle, rather than giving 100 mcg to each side.
Intermittent SubQ charts	100–300 mcg per administration two or three times weekly is separate from a 500-mcg-per-injection twice-weekly chart. A five-week user's vial wording cannot verify their per-shot amount.

Notes

Daily SubQ charts: 100–200 mcg total per day. A community guide repeats 100 mcg/day for 10 days and 100–200 mcg/day for 10–30 days. The original record separately contains 250 mcg/day table entries and 200–300 mcg/day upper charts. These are chart claims, not validated benefit or safety bands. r/NTNPerformance — Follistatin-344 peptide guide (Community guide · Accessed 2026-09-30)

Training-day IM: 50 or 100 mcg before workouts. The guide's 50 mcg IM chart specifies roughly 30 minutes beforehand and no rest-day use. An opened bodybuilding log describes 100 mcg split bilaterally into the trained muscle, not 100 mcg on each side. A recent 50 mcg/workout report leaves route unspecified. r/NTNPerformance — Follistatin-344 peptide guide (Community guide · Accessed 2026-09-30) · Anabolic Steroid Forums — 5 days into researching follistatin 344 untagged (Personal report · Accessed 2026-09-30) · r/Biohacking — localized muscle-growth compound/stack discussion (Personal report · Accessed 2026-09-30)

Intermittent SubQ charts: 100–300 mcg per administration, two or three times weekly. A separate original chart gives 500 mcg per injection twice weekly for four to five weeks. These incompatible schedules stay separate from daily totals. The five-week Reddit account ambiguously describes a 1 mg vial and two weekly shots; it cannot verify 500 mcg per shot. r/Peptides — Has anyone here tried follistatin, with what results? (Personal report · Accessed 2026-09-30)

Source context — Anabolic Steroid Forums — 5 days into researching follistatin 344 untagged: Unverified untagged label and product; forum includes supplier advertising and author signature contact, so commercial influence cannot be ruled out. Photos not assessed as muscle-mass evidence. Later recollection has imprecise chronology.

Source context — r/Biohacking — localized muscle-growth compound/stack discussion: Route unspecified, multiple concomitant agents, no measured muscle endpoint. Reply's MOTS-c mechanism and mixture suggestions are not accepted. Publication day not inferred from relative timestamps.

Half-life, onset & duration

Felt onset	Day-two or day-five pumps appear in some logs. Older notes place fullness around weeks 1–2 and size claims around weeks 2–3.
Felt duration	No dependable single-dose benefit window emerges. One retention claim lacks a clear follow-up interval; gene-product stories of months or a year do not describe protein-vial duration.
Half-life	About 90 minutes is a circulated protein claim without a supporting measurement. Conflicting multi-hour to day-scale claims do not establish human, route-specific clearance.

Notes

Day 2 or day 5 pumps in some reports; no change at day 7 in another. Reddit's early-pump claim and a day-five IM log contrast with an IronMag user's day-seven null report at 100 mcg/day IM. That user later described harder arms after changing the amount. The original places fullness claims around weeks 1–2 and size claims around weeks 2–3. Pumps, scale changes and measured muscle growth are different endpoints. r/Biohackers — Follistatin-344 early-pump and retention replies (Personal report · Accessed 2026-09-30) · Anabolic Steroid Forums — 5 days into researching follistatin 344 untagged (Personal report · Accessed 2026-09-30) · IronMag — how long before I notice anything from follistatin-344 (Personal report · Accessed 2026-09-30)

No dependable single-dose benefit duration emerges. One Reddit user claims 10 pounds gained over 20 days with only two lost afterward, without a clear follow-up interval, route or body-composition method. That is a retention claim, not measured drug duration. Gene-product stories of months or a year describe continued expression, not protein-vial persistence. r/Biohackers — Follistatin-344 early-pump and retention replies (Personal report · Accessed 2026-09-30)

About 90 minutes is a circulated protein claim. A transcript of Chris Bell's podcast discussion repeats it without a supporting measurement. The original also records conflicting multi-hour to roughly day-scale claims. Their human, route-specific origins remain unresolved. Half-life means an amount falls by half, not that everything disappears at that time. Danny Jones Podcast #325 with Chris Bell — transcript of follistatin discussion (Secondhand community claim · Accessed 2026-09-30)

Source context — r/Biohackers — Follistatin-344 early-pump and retention replies: Route, analytical product verification, body-composition method and post-course observation interval not supplied in inspected replies. Collapsed/deleted branches not inspected; no TRT or female lifting claim attributed to this opened body. Exact reply dates not exposed in opened relative-time view.

Source context — IronMag — how long before I notice anything from follistatin-344: Bodybuilding 'rat' euphemism, product unverified, subjective change after dose/route changes and final disappointment; day-seven statement is not the final whole-course outcome. No efficacy or fake-product diagnosis inferred.

Source context — Danny Jones Podcast #325 with Chris Bell — transcript of follistatin discussion: Third-party AI transcript; audio not played or checked. Statement cites no human PK source and misdescribes half-life as disappearance. Guest's minicircle experience is a different delivery class and is not used as protein-vial efficacy evidence.

Cycles people discuss

Short daily blocks	Charts give 10–30 days with three or four weeks off; users also describe 20-day courses. Higher-amount charts use other patterns. A break has not been shown to reset growth signaling or protect users.
Longer or workout-based use	Six-to-eight-week runs, an eight-weeks-on/eight-off IM chart and a 20-workout account are separate patterns. None establishes safe repeat use.

Notes

Short daily blocks: 10–30 days, with three or four weeks off in charts. The guide repeats this calendar; original charts distinguish 10–14-day first looks from 20–30-day blocks. Inspected users describe 20-day courses. Original higher-dose tables instead pair 10–20 days with at least four weeks off. The claimed growth-signaling reset from a break remains a rationale, not demonstrated protection. r/NTNPerformance — Follistatin-344 peptide guide (Community guide · Accessed 2026-09-30) · r/Biohackers — Follistatin-344 early-pump and retention replies (Personal report · Accessed 2026-09-30)

Longer patterns: six to eight weeks, or a workout count rather than a calendar. The IM guide gives eight weeks on/eight off; original charts include six-to-eight-week runs and one four-on/four-off acquaintance plan. A recent account counts 20 workouts. Other original speculation uses 50–100 mcg for 10–14 days a few times yearly. No pattern establishes safe repeat use. r/NTNPerformance — Follistatin-344 peptide guide (Community guide · Accessed 2026-09-30) · r/Biohacking — localized muscle-growth compound/stack discussion (Personal report · Accessed 2026-09-30)

Stacks

Growth combinations	CJC/ipamorelin, IGF-1 LR3, HGH, tesamorelin, MK-677 and testosterone/AAS appear in separate stacks. A 50-mcg/workout account also used CJC/ipamorelin and IGF-1 LR3.
Connective-tissue combinations	BPC-157 and TB-500/TB-4 are proposed as tendon or ligament buffers. That protective claim is unestablished; a favorable stack cannot identify follistatin's contribution.

Notes

A stack's success cannot be assigned to one ingredient. The recent 50 mcg/workout report also used CJC/ipamorelin and IGF-1 LR3; a reply challenges attribution. Original discussions add HGH, tesamorelin, MK-677, testosterone, YK-11 or epicatechin. BPC/TB combinations are proposed as connective-tissue buffers, but that protective claim is not established. r/Biohacking — localized muscle-growth compound/stack discussion (Personal report · Accessed 2026-09-30)

MK-677: Oral GH secretagogue paired for recovery/appetite/IGF-1 tone during FS blocks. [community]

Proposed connective-tissue protection: FS-344 + BPC-157 + TB-500/TB-4 (“Wolverine-adjacent”) appears during heavy training. Users invoke a possible lag in tendon/ligament adaptation if strength increases quickly; the combination has not established that protection. [community]

Watch for

Local and whole-body symptoms	Pain, swelling, itching, fatigue and joint complaints are reported. In one SubQ account, pain eased after three days but the bump and itch persisted a week; the cause was not diagnosed.
Vision changes	A published series describes retinal fluid problems in 11 bodybuilders after reported 1 mg SubQ administrations. It does not establish a risk rate or show that smaller amounts avoid the problem.
Contents and wider risks	A historical survey found follistatin in nine of 17 labeled products, not a current-market success rate. Fertility and growth-pathway questions remain open; the saved 2026 WADA list prohibits follistatin at all times.

Notes

Unwanted effects can outlast the injection day. An Eroids SubQ account describes pain easing after three days but a bump and itch still present after a week. This is one reaction's duration, not an expected course or a diagnosis. Eroids — jimmie's Follistatin 344 reaction (Personal report · Accessed 2026-09-30)

Retinal problems have been reported after high-dose exposure. A published case series describes 11 male bodybuilders with central serous chorioretinopathy, a retinal fluid disorder, after reported 1 mg SubQ administrations. It establishes a concerning association, not a frequency estimate, dose threshold or proof that smaller amounts avoid the problem. Dağ et al. (2020) — Central serous chorioretinopathy associated with high-dose follistatin-344 (Official context · Accessed 2026-09-30)

A label cannot establish protein identity. A 2019 analytical survey found follistatin in nine of 17 labeled products; other samples contained different peptides. Positive samples were His-tagged and highly oligomerized. This historical sample cannot estimate today's market or confirm the contents of an individual user's vial. Reichel, Gmeiner and Thevis (2019) — Detection of black market follistatin 344 (Official context · Accessed 2026-09-30)

Fertility and other growth-pathway questions remain open. Activin binding is why reproductive signaling enters the discussion. Community worries also include tendon adaptation, cardiac effects and cancer-related signaling. They are not demonstrated complication rates for gym users, and quiet bloodwork or a symptom-free log cannot settle them. r/NTNPerformance — Follistatin-344 peptide guide (Community guide · Accessed 2026-09-30) · r/Peptides — Has anyone here tried follistatin, with what results? (Personal report · Accessed 2026-09-30)

Tested sport: prohibited at all times. WADA's 2026 list names follistatin under S4.3, myostatin-binding proteins. A community half-life estimate is not a drug-test clearance window. WADA — 2026 Prohibited List, S4.3 (Official context · Accessed 2026-09-30)

Source context — Eroids — jimmie's Follistatin 344 reaction: No diagnosis or product testing; author's cellulitis comparison is not confirmation of infection. Preparation details deliberately excluded. Forum advertising and source discussion are not endorsements.

Source context — Dağ et al. (2020) — Central serous chorioretinopathy associated with high-dose follistatin-344: Retrospective single-institution case series without a comparison denominator; product purity and causation not established by abstract. Subscription full text not inspected. Does not establish a safer lower dose.

Source context — Reichel, Gmeiner and Thevis (2019) — Detection of black market follistatin 344: Historical small analytical sample; full journal methods not inspected. Does not identify today's brands, establish a current counterfeit percentage or explain a particular user's symptoms.

Source context — WADA — 2026 Prohibited List, S4.3: Sport prohibition context only; not a legality, product-identity or clearance certification.

Full notes

What Follistatin 344 actually means

344 names the precursor; 315 is the processed protein. Follistatin is a glycoprotein, larger than the short peptides usually discussed in gym communities. Removing the precursor's 29-amino-acid signal sequence leaves FS-315. It binds activins as well as myostatin, so the popular muscle-brake explanation leaves out other biological effects. Official context
Protein injection and gene delivery cannot share one dose chart. Community protein-vial logs use micrograms. Gene delivery supplies instructions for cells to make follistatin; it does not simply inject the same protein. FLGR-242, plasmid products and oral yolk-derived supplements also need their own identities. Their amounts or claimed persistence cannot be pasted onto an ordinary FS-344 vial. Community guide Community

Benefits people seek and report

Fullness, pumps and easier recovery between sets. One Reddit account describes those changes during a planned six-week run with BPC-157, but also hand-joint pain. Another five-week account describes modest fullness while training harder and improving diet. Neither establishes new muscle tissue or isolates follistatin's contribution. Personal report Personal report
No change is part of the record. An Eroids author reported no body-composition or measurement change after 20 days at 100 mcg/day, despite concurrent testosterone, deca and HCG. A nonresponse does not prove a fake product or justify a higher amount. Personal report

Doses people discuss

Reported amounts, not instructions. mcg means micrograms; 1,000 mcg equals 1 mg. SubQ/SC means beneath the skin; IM means into muscle.

Daily SubQ charts: 100–200 mcg total per day. A community guide repeats 100 mcg/day for 10 days and 100–200 mcg/day for 10–30 days. The original record separately contains 250 mcg/day table entries and 200–300 mcg/day upper charts. These are chart claims, not validated benefit or safety bands. Community guide Community
Training-day IM: 50 or 100 mcg before workouts. The guide's 50 mcg IM chart specifies roughly 30 minutes beforehand and no rest-day use. An opened bodybuilding log describes 100 mcg split bilaterally into the trained muscle, not 100 mcg on each side. A recent 50 mcg/workout report leaves route unspecified. Community guide Personal report Personal report
Intermittent SubQ charts: 100–300 mcg per administration, two or three times weekly. A separate original chart gives 500 mcg per injection twice weekly for four to five weeks. These incompatible schedules stay separate from daily totals. The five-week Reddit account ambiguously describes a 1 mg vial and two weekly shots; it cannot verify 500 mcg per shot. Community Personal report
Sparse charts and aggressive outliers have weaker provenance. The original includes 1.0, 1.5 or 2.5 mcg/kg/day heuristics; a roughly 1 mg loading claim followed by about 100 mcg bilaterally daily for about 20 days; and 500 mcg bilateral-IM claims with unspecified high rest-day SubQ totals. The bilateral wording is ambiguous. None establishes an escalation ladder or safe ceiling. Community

Half-life

About 90 minutes is a circulated protein claim. A transcript of Chris Bell's podcast discussion repeats it without a supporting measurement. The original also records conflicting multi-hour to roughly day-scale claims. Their human, route-specific origins remain unresolved. Half-life means an amount falls by half, not that everything disappears at that time. Creator podcast via Wave transcript Community

Onset: when people notice something

Day 2 or day 5 pumps in some reports; no change at day 7 in another. Reddit's early-pump claim and a day-five IM log contrast with an IronMag user's day-seven null report at 100 mcg/day IM. That user later described harder arms after changing the amount. The original places fullness claims around weeks 1–2 and size claims around weeks 2–3. Pumps, scale changes and measured muscle growth are different endpoints. Personal report Personal report Personal report Community

Duration: what lasts after use

No dependable single-dose benefit duration emerges. One Reddit user claims 10 pounds gained over 20 days with only two lost afterward, without a clear follow-up interval, route or body-composition method. That is a retention claim, not measured drug duration. Gene-product stories of months or a year describe continued expression, not protein-vial persistence. Personal report Community
Unwanted effects can outlast the injection day. An Eroids SubQ account describes pain easing after three days but a bump and itch still present after a week. This is one reaction's duration, not an expected course or a diagnosis. Personal report

Cycles and breaks

Short daily blocks: 10–30 days, with three or four weeks off in charts. The guide repeats this calendar; original charts distinguish 10–14-day first looks from 20–30-day blocks. Inspected users describe 20-day courses. Original higher-dose tables instead pair 10–20 days with at least four weeks off. The claimed growth-signaling reset from a break remains a rationale, not demonstrated protection. Community guide Personal report Community
Longer patterns: six to eight weeks, or a workout count rather than a calendar. The IM guide gives eight weeks on/eight off; original charts include six-to-eight-week runs and one four-on/four-off acquaintance plan. A recent account counts 20 workouts. Other original speculation uses 50–100 mcg for 10–14 days a few times yearly. No pattern establishes safe repeat use. Community guide Personal report Community

Cautions that matter

Pain, swelling, fatigue and joint complaints. Logs describe painful local reactions and tiredness; the recent user also taking BPC-157 stopped a week early because of hand-joint pain. Original notes also mention flu-like malaise, headache, appetite or sleep changes, nausea and dizziness. These reports do not identify incidence, infection or which ingredient caused a symptom. Personal report Community
A label cannot establish protein identity. A 2019 analytical survey found follistatin in nine of 17 labeled products; other samples contained different peptides. Positive samples were His-tagged and highly oligomerized. This historical sample cannot estimate today's market or confirm the contents of an individual user's vial. Official context
Retinal problems have been reported after high-dose exposure. A published case series describes 11 male bodybuilders with central serous chorioretinopathy, a retinal fluid disorder, after reported 1 mg SubQ administrations. It establishes a concerning association, not a frequency estimate, dose threshold or proof that smaller amounts avoid the problem. Official context
Fertility and other growth-pathway questions remain open. Activin binding is why reproductive signaling enters the discussion. Community worries also include tendon adaptation, cardiac effects and cancer-related signaling. They are not demonstrated complication rates for gym users, and quiet bloodwork or a symptom-free log cannot settle them. Community guide Personal report Community
Tested sport: prohibited at all times. WADA's 2026 list names follistatin under S4.3, myostatin-binding proteins. A community half-life estimate is not a drug-test clearance window. Official context

What people disagree about

Local growth versus a whole-body effect. IM users chase particular muscles, while SubQ users describe general fullness. Posts argue both sides without verifying local targeting. Timing preferences likewise split among pre-workout, post-workout with food, morning and divided daily amounts; they do not establish an optimal window. Personal report Community Community
A stack's success cannot be assigned to one ingredient. The recent 50 mcg/workout report also used CJC/ipamorelin and IGF-1 LR3; a reply challenges attribution. Original discussions add HGH, tesamorelin, MK-677, testosterone, YK-11 or epicatechin. BPC/TB combinations are proposed as connective-tissue buffers, but that protective claim is not established. Personal report Community
Tagged, expensive or hard to find does not settle effectiveness. Forum replies blame tags or authenticity for pain and nonresponse; the claims do not prove either explanation. Cost curtailed one user's five-week course. The original also contains a pain-only X report and mixed modified-product anecdotes; these remain reports, not a success-rate calculation. Anabolic Steroid Forums Personal report Community

Why the research headlines differ

The small human trial tested gene transfer in muscular dystrophy. Six Becker muscular dystrophy patients received AAV1.CMV.FS344 into the quadriceps; four improved their walking-test distance and two did not. This does not establish healthy-athlete protein-vial outcomes. Vector-genome amounts cannot be converted into micrograms. Official context
Engineered protein studies do not measure an ordinary vial's half-life. FST315-Fc variants were deliberately changed to prolong exposure and were studied in mouse disease models. Those constructs, viral vectors, plasmids and experimental mRNA delivery cannot supply interchangeable human clearance or cycle values. Animal context Community guide