Follistatin 344 Pen

Before you start
Check the batch number on the pen against the certificate of analysis on this page. If they don't match, don't use the pen. Contact us and we'll replace it.

Inspect the solution through the window. It should be clear and free of particles. Copper peptide solutions are blue, and that colour is expected. Cloudiness, discolouration or visible matter means the pen should not be used.

The pen
Each pen arrives pre-filled, in solution, at the concentration on the label. There is nothing to reconstitute, no bacteriostatic water to add and no concentration to calculate.

The dose counter is mechanical. Turning the dial advances it one increment at a time, with an audible click per increment, and the number in the window is the amount set. The counter cannot be turned past the volume remaining.

Pens take standard pen needles, supplied with your order. Fit a fresh one each time and remove it afterwards. Leaving a needle attached lets air into the cartridge and can affect what the counter reads next.

Storage
Refrigerate at 2–8°C on arrival and keep the pen in its carton. Peptides in solution degrade faster in light, and copper peptides faster still.

Do not freeze. Freezing damages peptides in solution and the pen cannot be relied on afterwards, whatever it looks like.

Return the pen to refrigeration between uses once the seal is broken. A cold pen is stiffer to dial, so leaving it out for a few minutes beforehand makes the counter turn more smoothly.

Disposal
Used needles go into a sharps container, not household waste. UK pharmacies and local councils both supply them, and most councils collect full ones on request.

Supplied for laboratory research use only. Not for human or veterinary use, and not a medicine. Nothing on this page describes a protocol, a schedule or an application, and none should be inferred.

Every batch is tested before release
No batch reaches our shelves without a report from an independent laboratory. Testing is done by a third party with no commercial interest in the result, not by us and not by the manufacturer.

What the certificate shows
Identity, confirming the compound is what the label says it is. Purity, measured by high-performance liquid chromatography and reported as a percentage. The date of testing and the batch number the result applies to.

How to check it yourself
Every pen carries a batch number, and the certificate on this page carries the same number. If the two don't match, something has gone wrong in our dispatch and we want to hear about it. We'll replace the pen.

Certificates are published as the laboratory issued them. We don't retype results, summarise them or crop the report.

Cold chain
Stock is held refrigerated and ships in insulated packaging with a cold pack. Orders are dispatched so they travel over the shortest practical window rather than sitting in a depot over a weekend.

If a pen arrives damaged, warm, or not matching its certificate, contact us within 48 hours of delivery and we'll replace it.

Why is this pen 1mg when most are 5mg?

Follistatin 344 is a full 344 amino acid glycoprotein, many times the mass of the short peptides in the rest of the range. Milligram amounts are not comparable between a protein this size and a five amino acid peptide.

Are the well-known muscle results from this protein?

Not directly. The most cited animal results use viral gene delivery so the tissue produces follistatin continuously. Administering the protein is a different experiment and has a much smaller published base.

What are the 344 and 315 numbers?

They are two isoforms of the same protein differing at the tail, which changes how strongly each sticks to cell surfaces. This is the 344 isoform.

Is this prohibited in sport?

Yes. It appears on the World Anti-Doping Agency prohibited list. If you are a tested athlete, this is not a grey area.

How many doses are in a 1mg pen?

That depends entirely on the increment you dial, so there is no single answer. The counter shows what is set and the pen cannot be turned past the volume remaining.