Calculator
Peptide Unit Converter
Vials are labelled in milligrams, research papers quote micrograms, and a syringe is marked in units — three ways of writing the same quantity, and the reason a number that looked right on paper reads wrong at the bench. Enter the concentration you mixed and any one quantity you already have, in whichever of the four units you have it in, and this restates it in the other three. It converts what you give it, it has nothing of its own to propose, and it will never suggest a dose.
This tool does not recommend a dose
One quantity, four ways
Calculator
Required, and not optional in disguise: two of the four units below measure mass and two measure volume, and this is the only thing that connects them. If you mixed the vial yourself it is the labelled mass divided by the water you added.
Whatever figure you are trying to convert — off a paper, off a label, or read from a syringe barrel. Pick the unit it is currently in below.
Enter a concentration, a quantity, and the unit that quantity is currently in. All three are required — without the concentration there is no exchange rate between mass and volume, and the conversion cannot be done at all.
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What this calculator does not tell you
It does not know what is in your vial
It does not know whether a quantity is appropriate
It does not verify sterility, purity, or legality
The arithmetic
How the math works
Everything routes through milligrams — one hop in from whichever unit you chose, one hop out to each of the other three. That is deliberate: it means there is exactly one conversion path between any two units and no chance of two routes disagreeing.
Micrograms to milligrams is a division by 1,000 and nothing else — no concentration involved, because both measure mass.
Millilitres to milligrams is a multiplication by your concentration, and units to millilitres is a division by 100. Those two are where the concentration earns its keep: crossing from a volume to a mass is impossible without it, which is why the field is required rather than defaulted.
Glossary
Key terms
- Concentration (mg/mL)
- How much peptide sits in each millilitre of the mixed solution — the exchange rate between a mass and a volume.
- Syringe units (U-100)
- The markings on a standard U-100 insulin syringe, where 100 units equal 1 millilitre. A different syringe, such as a U-40, uses a different scale entirely.
- Microgram (mcg)
- One thousandth of a milligram. Papers frequently quote micrograms where a vial label quotes milligrams, and confusing the two is a thousand-fold error.
- Mass versus volume
- Micrograms and milligrams measure how much peptide there is; millilitres and syringe units measure how much liquid there is. Only a concentration connects the two.
Before you calculate
Approval status of peptides commonly reconstituted this way
The arithmetic above is identical no matter which peptide is in the vial. What you are legally able to obtain is not — it varies by compound, and it is worth checking before you calculate anything.
- TesamorelinFDA-approved
- TirzepatideFDA-approved
- CJC-1295 and IpamorelinCompounding restricted
- BPC-157Research use only
- MOTS-cResearch use only
Questions
Frequently asked questions
How many micrograms are in a milligram?
One thousand. That single factor is where most conversion errors on this subject come from: a figure quoted in micrograms in a paper and entered in milligrams at the bench is off by a factor of a thousand in the direction that matters. The converter above applies the factor for you and shows it in the working, so you can see which way it went.
Can I convert units to milligrams without knowing the concentration?
No, and any tool that appears to is hiding an assumption. A syringe unit measures VOLUME, not mass — one unit is one hundredth of a millilitre on a standard U-100 syringe, whatever is dissolved in it. Turning that volume into a mass needs the concentration of your particular solution, which is why it is a required field here rather than a silent default.
Does this converter know what my vial contains?
It does not, and it has no product database to consult. The concentration field is a number you calculate or read yourself — if you mixed the vial, it is the labelled mass divided by the diluent you added, which the reconstitution calculator on this site works out step by step. Everything the converter prints is derived from that figure and the one quantity you type beside it.
Why does the same quantity look so different in each unit?
Because two of the four units measure mass and two measure volume, and the concentration is the exchange rate between them. Micrograms and milligrams differ only by a factor of a thousand, and millilitres and units only by a factor of a hundred — but crossing between the mass pair and the volume pair goes through your concentration, so changing what you mixed changes the unit figure while the milligram figure stays exactly where it was.
Medical disclaimer: This content is for general educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a licensed healthcare professional before starting, stopping, or changing any treatment.