Why are peptides dosed in micrograms instead of milligrams?

Peptides are biologically active at very small quantities. A 5 mg vial of BPC-157 contains 5000 mcg - enough for 10 doses at 500 mcg each. Using micrograms allows for more precise dosing at these small quantities.

What does IU mean on a syringe?

IU stands for International Units and is a scale on U-100 insulin syringes. For U-100 syringes: 10 IU = 0.1 mL. This is important because peptide draw volumes are calculated in mL, which you then convert to IU marks on the syringe.

Guides

Math & Units

Mg to Mcg Conversion for Beginners

Q: How many mcg are in 1 mg?

1 mg (milligram) = 1000 mcg (micrograms). To convert mg to mcg, multiply by 1000. To convert mcg to mg, divide by 1000.

Peptides are sold in milligrams but dosed in micrograms. This single unit difference trips up more researchers than any other step. Here's how it works.

TL;DR - 1 mg = 1,000 mcg. Multiply mg by 1,000 to get mcg. A 5 mg vial contains 5,000 mcg - enough for ten 500 mcg doses.

Calculate your dose right here

The Units

Three Units You Need to Know

Gram

Vial labeling reference

Milligram

Vial sold amount

Microgram

mcg / µg

Dose amount

Each unit is 1,000× smaller than the one before it. So: 1 g = 1,000 mg = 1,000,000 mcg.

The Formula

How to Convert

mg → mcg

mcg = mg × 1,000

Example: 5 mg × 1,000 = 5,000 mcg

mcg → mg

mg = mcg ÷ 1,000

Example: 500 mcg ÷ 1,000 = 0.5 mg

Got the conversion? Now run the math.

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Reference Table

Common Peptide Vial Conversions

Vial Size	In Micrograms	Doses at 500 mcg
1 mg	1,000 mcg	2 doses
2 mg	2,000 mcg	4 doses
5 mg	5,000 mcg	10 doses
10 mg	10,000 mcg	20 doses
30 mg	30,000 mcg	60 doses

FAQ

Common Questions

How many mcg are in 1 mg?

1 mg = 1,000 mcg. To convert mg to mcg, multiply by 1,000. To convert mcg to mg, divide by 1,000.

Why are peptides dosed in micrograms?

Peptides are biologically active at very small quantities. A typical BPC-157 dose of 500 mcg is only 0.5 mg - smaller than a grain of sugar. Using mcg lets researchers express these quantities without confusing decimals.

What is IU on a syringe?

IU (International Units) is the scale on U-100 insulin syringes. For a U-100 syringe, 10 IU = 0.1 mL. Your ASCEND calculator shows draw volume in both mL and IU so you can read it directly off the syringe markings.

My vial says 5mg - how many doses is that?

It depends on your dose. At 500 mcg/dose: 5 mg = 5,000 mcg = 10 doses. At 250 mcg/dose: 5 mg = 20 doses. Use the ASCEND calculator to find exact doses per vial for your specific peptide and protocol.

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Now do the math

Calculate your exact draw

You've read the why and the how. Open the ASCEND calculator, pick your peptide, and get the IU draw in 10 seconds.

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