Basics

The concepts that recur on every peptide page, explained once, properly.

Reconstitution

Peptides ship as a freeze-dried powder (a lyophilisate) in a glass vial. Before use you dissolve that powder in a sterile liquid, which is called reconstitution. The usual choice is bacteriostatic water: water with 0.9% benzyl alcohol, which inhibits bacterial growth and keeps the vial usable for weeks after it is first punctured. Sterile water without a preservative also works, but is then intended for single use.

Run the liquid down the side of the vial rather than firing it directly onto the powder. Then roll the vial gently between your hands until everything has dissolved. Shaking can damage the peptide chain.

Once reconstituted, keep the vial in the fridge (2–8 °C) and out of the light. Bacteriostatic water buys weeks; plain sterile water, once opened, only a day or two. Dry powder is far more stable than the dissolved peptide, which is why these compounds are shipped freeze-dried and reconstituted only when needed.

Concentration

Concentration follows from two numbers: how many milligrams are in the vial, and how many millilitres you add.

concentration (mg/ml) = peptide (mg) ÷ volume added (ml)

A U100 insulin syringe has 100 units per millilitre, so one unit is 0.01 ml. That gives you the conversion to the markings on your syringe:

units = dose (mcg) ÷ concentration (mcg/ml) × 100

Remember that 1 mg equals 1000 mcg (micrograms). Most arithmetic errors happen at exactly that step. The calculator handles it for you.

Units, IU and milligrams

Three different quantities get called "units", and confusing them is one of the few mistakes on this site that can hurt you rather than merely waste a vial.

Milligrams (mg)

Mass. How much substance is in the vial. This is what the calculator asks for.

Syringe units

Volume. A mark on the barrel of a U100 insulin syringe. One unit is 0.01 ml of liquid, whatever is dissolved in it. This is what the calculator answers with.

International Units (IU)

Biological activity, not mass and not volume. How much effect a standardised assay says the substance produces. Every substance has its own conversion, and for some there is none at all. The letters stand for International Units — not "injection units", a natural guess that is wrong and that feeds exactly the mix-up below.

The trap is that a syringe unit and an International Unit look identical when someone writes "10 units", and the markings on an insulin barrel invite being read as the "injection units" a vial's IU figure refers to. They are not the same thing. There is one substance for which they genuinely coincide — insulin. A U100 syringe is called U100 because it holds 100 IU of insulin per millilitre, and the barrel was marked for that. For everything else those markings are only volume: a "unit" on the syringe is 0.01 ml of whatever you dissolved, and it carries no information about biological activity. That historical accident is the whole source of the confusion.

Where a compound is dosed in IU, you cannot convert to milligrams without knowing that specific product's activity. Growth hormone is the case people meet most often: roughly 1 mg equals 3 IU, so someone reading "2 IU per day" in older or grey-market material and typing 2 into a milligram field has asked for three times the dose they meant. Human chorionic gonadotropin, gonadotropins and calcitonin are dosed in IU as well.

How we label evidence

Every peptide gets one of three labels. They describe how solid the research is, not how popular the compound is.

preclinical

Cell and animal research only. There are no meaningful published human studies. What works in a rat frequently does not work in a person.

early-clinical

Human studies exist, but they are small, short, uncontrolled, or have not been independently replicated.

clinically proven

Large randomised trials resulting in an approved medicine. The compound has a licensed indication and a known side-effect profile.

Regulatory status

Many compounds on this site are sold as research chemicals, labelled "not for human consumption". That is not a formality. It means nobody is checking purity, sterility or dosage, and no party carries liability when something goes wrong. Independent analyses of such products regularly find off-target quantities or contaminants.

Safety

This site describes what the literature and published user protocols say. That is not the same as a recommendation. A few things are consistently underestimated:

• Interactions with medication you already take are rarely studied for these compounds.
• Injecting carries a real infection risk; sterile technique is not optional.
• An existing condition — a cancer history, diabetes, cardiovascular disease, pregnancy — changes the risk profile fundamentally.
• Discuss use with a doctor. That sounds like an obligatory line, but the reason is concrete: a doctor can check bloodwork you have no visibility of yourself.