Worked example
Add 2 mL of water to a vial holding 5 mg of Sermorelin. The concentration is 5 ÷ 2 = 2.5 mg/mL, or 2,500 mcg in every millilitre. On a U-100 syringe, where 100 units make 1 mL, each unit holds 25 mcg and each 10 units hold 250 mcg.
Change the water and only the concentration changes. With 4 mL instead, each 10 units hold 125 mcg, half as much, and any given mass takes twice the units to measure. These numbers illustrate the arithmetic; they are not amounts to use.
Concentration table
Common Sermorelin vial sizes against common water volumes. The last column is what 10 units on a U-100 syringe hold.
| Vial | Water | Concentration | 10 units (U-100) hold |
|---|---|---|---|
| 2 mg | 1 mL | 2 mg/mL | 200 mcg |
| 2 mg | 2 mL | 1 mg/mL | 100 mcg |
| 2 mg | 3 mL | 0.667 mg/mL | 66.7 mcg |
| 5 mg | 1 mL | 5 mg/mL | 500 mcg |
| 5 mg | 2 mL | 2.5 mg/mL | 250 mcg |
| 5 mg | 3 mL | 1.667 mg/mL | 166.7 mcg |
| 10 mg | 1 mL | 10 mg/mL | 1 mg |
| 10 mg | 2 mL | 5 mg/mL | 500 mcg |
| 10 mg | 3 mL | 3.333 mg/mL | 333.3 mcg |
Notes for Sermorelin vial math
- Microgram amounts from small vials land in single or low double-digit units. On a 1 mL syringe marked every 2 units, odd-unit results fall between marks; a 0.3 or 0.5 mL syringe reads them directly.
- Do not confuse sermorelin with CJC-1295 no DAC (Mod GRF 1-29). Both are 29 amino acids based on GHRH, but Mod GRF has four substitutions. The math is the same; the molecules are not.
- Sermorelin is about 3,358 g/mol, so per milligram it is a similar number of molecules to CJC-1295 no DAC.
Storage and handling
- The discontinued Geref was a lyophilized product reconstituted before use. No current approved label exists, and research material has no stability data.
- General practice: refrigerate reconstituted vials (2-8 °C), avoid freezing, protect from light, label.