Question 1

What amounts of follistatin did the published studies use?

Accepted Answer

None that can be read as a milligram figure, and the reason is the form of delivery rather than any secrecy about it. The protein study, published in 2022, states that its rats received FST protein (isoform FS-288) or sham treatment, and it names the delivery as a pump under the skin. Its summary does not give the amount the pump released each day, so the one protein study on record cannot supply a number. The 2024 gene-delivery paper describes systemic administration of follistatin DNA gene therapy, where the measured result was a rise in circulating follistatin rather than a quantity injected. The cancer studies used follistatin mRNA lipid nanoparticles, small fat bubbles carrying a genetic message, so their dose is a quantity of RNA and not of protein. Three studies, and in each the quantity that mattered was a delivery vehicle rather than the protein a vial would hold.

Question 2

Who received those amounts?

Accepted Answer

Each recipient was chosen because something was already wrong with its muscle, nerve or tumour, and that shapes what any amount meant. The rats in the protein study had their nerve cut for three or six months, or underwent a sham operation, before the protein was given. The study's starting point was that muscle recovery following peripheral nerve repair is sub-optimal, so the protein was being asked to help a damaged muscle regrow. The mRNA work used mice carrying head and neck tumours, and its goal was to lower activin A, which the authors call a pivotal driver of metastasis and cachexia, the wasting of advanced illness. The single human use involved a small group of patients with inclusion body myositis, a disease in which muscle becomes inflamed and weakens. A healthy adult appears nowhere in that list. An amount chosen to rescue an injured or wasting muscle is set against a different baseline from one chosen to add muscle to a healthy body, and the second has not been asked.

Question 3

How was follistatin administered in the studies?

Accepted Answer

Four routes appear, and only one of them puts a protein under the skin. The rats received protein from a subcutaneous osmotic pump, a small implant placed under the skin that releases its contents slowly over a period of time. The myositis patients received intra-muscular injections of a virus, AAV1, carrying the gene for the FS344 isoform. The 2024 gene paper gave its particles into the circulation of mice and non-human primates, where they showed broad biodistribution, meaning they spread widely through the body. The 2026 lung cancer study tuned its particles so they would deliver follistatin mRNA preferentially to tumours in mice. Route changed what was being delivered, and so it changed what an amount meant. A pump dose, a viral dose and a particle dose are not three sizes of one thing.

Question 4

How often was follistatin given, and for how long?

Accepted Answer

The published summaries say less about schedule than a reader would hope. A pump implant delivers continuously, so the rat study had no injection frequency at all, only a period during which the device was running. The waiting period before dosing is clearer than the dosing itself, since outcomes were reported after three months of denervation and after three months of sham denervation. For the gene particles, the 2024 paper reports that they maintain activity upon repeat dosing in animals, which tells you a second dose worked but not how far apart the doses were. The myositis summary gives no injection count or follow-up period. Frequency and duration therefore cannot be lifted from any of these studies, and that is a limit of the record rather than a detail left out of this page.

Question 5

Is there a follistatin dosage chart?

Accepted Answer

There is not, and the reason is structural rather than an oversight. A chart needs one unit running down a column, and the follistatin studies use at least three: a protein pumped into a rat, a gene packed into a virus or particle, and an mRNA message wrapped in fat. Even the protein study measured success partly by counting cells, reporting that direct protein delivery enhanced satellite cell counts in rats after the nerve regrew. Satellite cells are the stem cells that repair muscle fibres. A count of them is a research outcome, not a dose, and it cannot be turned into an amount for a person. Any follistatin chart circulating online therefore did not come from these studies, and its figures belong to whoever wrote it rather than to the research.

Question 6

Where do the numbers attached to follistatin come from?

Accepted Answer

Mostly from trials that dosed something else and measured follistatin afterwards. A 2024 creatine trial gave 40 young adults creatine at 0.03 g per kilogram of body mass alongside eight weeks of resistance training, and then reported their follistatin-to-myostatin ratio. That per-kilogram figure is a creatine dose, and it describes creatine. Exercise trials publish their dose as sessions, such as resistance training three times a week, 60 minutes per session, for 16 weeks in older women with sarcopenia. A 2025 trial of 27 older people ran vibration or resistance training three times weekly for 12 weeks and recorded follistatin among its blood results. Every number in that paragraph is a dose of training or creatine. Read beside the word follistatin, it is easy to mistake for a follistatin dose, and it is not one.

Question 7

Does a dose-response appear anywhere?

Accepted Answer

Once, in fat cells in a laboratory dish, and the effect it shows is not the one most buyers are after. A 2021 study reports that in human adipocytes, the cells that store fat, follistatin dose-dependently increases free fatty acid release. Dose-dependent means more follistatin produced more of the effect across the concentrations tested. The same paper's human cohorts tie higher circulating follistatin to adipose tissue insulin resistance, which is fat tissue responding poorly to insulin. So the one dose-response curve among these sources runs towards a metabolic problem, and it was drawn in a dish rather than in a body. It does not tell a reader what any amount injected into a person would do, and it is not evidence that more is better.

Question 8

How much follistatin does the body make on its own?

Accepted Answer

The research measures the body's own output as a change from baseline rather than a daily amount, which is another reason no comparison dose exists. A 2016 study calls follistatin a liver-derived inhibitor of myostatin and tested how much the liver could release when the hormone balance of exercise was imitated by infusion. The peak change in follistatin was 1.9 in men with cirrhosis against 3.6 in healthy men, a significant gap. Training moves the level too, and in 60 overweight and obese men combined upper and lower body training produced the greatest increases in follistatin. Those are rises in the body's own supply, and they are not a reference amount that a vial could be measured against.

Question 9

Do FS344 and FS-288 change the amount?

Accepted Answer

They change what the amount refers to, which matters before any number does. FS344 is the isoform carried as a gene by AAV1 in the one human study, while FS-288 is the isoform given as protein to rats in 2022. Isoforms are different-length versions of one protein, and the research treats these two as separate tools rather than one product at two strengths. The rat study also measured the protein inside the treated muscle, with outcome measures that included muscle force, muscle histomorphology, and FST protein quantification. Measuring the protein in tissue was how those researchers confirmed it arrived. A person with a vial has no such check, and a label that does not name the isoform leaves even the starting point of the dose unknown.

Question 10

Why is a study amount not a protocol?

Accepted Answer

Because each amount was chosen for an animal, an injury and a delivery system, and none of those transfers. The 2022 authors describe their own aim as assessing the effect of direct delivery of recombinant FST protein on muscle recovery after reinnervation, which is a question about a repaired nerve. Their verdict was that follistatin had mixed effects on muscle weight and force, so even inside that model the amount was not shown to work. Turning a rat amount into a human one by body weight or surface area is a conversion that has not been validated for follistatin, and this page does not perform it. A protocol needs a tested amount, a tested schedule and a population like the reader. The follistatin record supplies none of the three for a healthy adult, which is different from saying the right amount is unknown but small.

Question 11

How do you reconstitute a follistatin vial?

Accepted Answer

None of the studies behind this page reconstituted a freeze-dried vial, so the research gives no method or concentration specific to follistatin. The 2024 gene paper built its particles in the laboratory using scalable microfluidic mixing, a controlled manufacturing step rather than anything resembling adding water to powder. The general arithmetic of turning a vial into a concentration, milligrams times one thousand divided by millilitres of diluent, works the same for any powder and can be run on your own numbers at the calculators. That arithmetic tells you how much of whatever is in the vial sits in each unit on the syringe. It says nothing about what the vial holds, which isoform it is, or whether any amount of it has been tested in a person.

Question 12

Is there a cycle or a break in the published work?

Accepted Answer

No study among the research behind this page tested cycling follistatin on and off, so there is no published cycle length or break. The nearest thing is the gene paper's report of repeat dosing, which its authors present as support for redosable gene therapies and genetic medicines. Redosable is a claim that a second dose still works, which is not the same as a schedule of doses with rests between them. The human trials that track follistatin run training blocks of 12 to 16 weeks, and in 21 older people both training styles raised blood follistatin within that 12-week window. A training block is a cycle of exercise, not of follistatin. It cannot stand in for a follistatin cycle, because no follistatin was given.

Question 13

Is there an approved follistatin dose to compare against?

Accepted Answer

No. Among these sources follistatin is not an approved medicine, so no regulator has published a schedule for it. A 1998 review ended on a hope rather than a plan. It said that some diseases are thought to come from too much of the growth signals follistatin blocks, so it may be possible to use follistatin as a therapeutic agent in them. The drugs that did move toward the clinic are antibodies, and a 2024 review says that alone or with weight-loss drugs they may help people lose fat while keeping or even adding muscle and bone. Whatever doses those antibodies end up with will belong to them. They are different molecules, and nothing about their schedules would carry across to a vial labelled follistatin.

Trial	Who	What was dosed	Length
2024 creatine trial	40 young adults	Creatine, 0.03 g per kg of body mass, with resistance training	Eight weeks
Resistance training trial	Older women with sarcopenia	Resistance training three times a week, 60 minutes per session	16 weeks
2025 trial	27 older people	Vibration or resistance training three times weekly	12 weeks

Follistatin protocols in the published literature