What this does
A 5 mg sermorelin vial in 2 mL of bacteriostatic water is 2.5 mg/mL. A 200 mcg draw is 0.08 mL, or 8 units on a U-100 syringe. Set the unit explicitly: sermorelin is labeled in milligrams and discussed in micrograms.
The vial size above is the size this compound is most commonly sold in, not a specification. Change it to match your label. The dose stays whatever you set — this tool does not suggest one.
What size vial does sermorelin come in?
Research vials are usually 5 mg, with 9 mg and 15 mg also in circulation. The discontinued pharmaceutical, Geref, was supplied differently again, so a figure quoted from the old label does not necessarily map onto a vial you can buy.
The same 5 mg vial at four water volumes:
| Water added | Concentration | Units for a 1 mg draw |
|---|---|---|
| 1 mL | 5 mg/mL | 20.0 units |
| 2 mL | 2.5 mg/mL | 40.0 units |
| 3 mL | 1.66667 mg/mL | 60.0 units |
| 5 mL | 1 mg/mL | 100.0 units |
Every row holds the same 5 mg. Watch the direction: more water means a weaker solution and therefore a larger draw. At 1 mL a 200 mcg dose is 4 units; at 5 mL the same dose is 20 units.
What was sermorelin dosed at?
Sermorelin is GHRH(1-29), the shortest fragment of growth-hormone-releasing hormone that keeps the activity. It reached the market as a drug and was then discontinued for commercial reasons rather than safety ones, which is a meaningfully different history from most of this catalog.
That history is also why the dosing question is confused. The historical label, the diagnostic-use protocols and the compounding-pharmacy figures are three different things, and the research market quotes whichever suits. The sermorelin guide separates them, and sermorelin vs tesamorelin compares it with the GHRH analog that still has a live label.
This tool converts what you enter. Where a figure is genuinely established it is worth naming its source, and for sermorelin that source is usually older than the market assumes.
The trap on this one: very small draws
Sermorelin doses are quoted in micrograms against a milligram vial, and at low water volumes the resulting draws get very small. At 5 mg in 1 mL, a 200 mcg dose is 4 units.
Below roughly five units, the error in reading a syringe stops being negligible relative to the dose. The fix is more water, not a steadier hand: the same 200 mcg from a 5 mL reconstitution is 20 units, which is comfortably readable. More water always means a larger draw, because it makes the solution weaker.
The other half of the arithmetic is that 1 mg = 1,000 mcg. Set the unit above rather than letting the tool assume. Sermorelin before and after covers what the compound has actually been shown to do.
Frequently asked questions
How many units is 200 mcg of sermorelin?
At 5 mg in 2 mL, which is 2.5 mg/mL, 200 mcg is 0.08 mL — 8 units on a U-100 syringe. At 1 mL of water it would be 4 units, which is near the limit of reliable measurement; at 5 mL it would be 20 units.
How much bacteriostatic water for a 5 mg sermorelin vial?
More rather than less is the sensible default here. Sermorelin doses are small, and a concentrated solution pushes the draw down toward the range where syringe reading error is a large fraction of the dose. 1 mL gives 5 mg/mL; 5 mL gives 1 mg/mL and a draw five times larger for the same dose.
Was sermorelin ever an approved drug?
Yes. It was marketed and then discontinued for commercial reasons rather than safety ones. That history is why several different dosing figures circulate: the historical label, diagnostic protocols and compounding-pharmacy practice are not the same thing.
Why does the unit matter so much?
Because 1 mg is 1,000 mcg, and sermorelin vials are labeled in milligrams while sermorelin doses are discussed in micrograms. An unlabelled number could mean either, and the answers differ by a factor of a thousand.
References
- American Society of Health-System Pharmacists (ASHP). Handbook on Injectable Drugs: Benzyl alcohol preservative compatibility and stability data. https://www.ashp.org/products-and-services/database-tools/handbook-on-injectable-drugs
- United States Pharmacopeia. (2024). Bacteriostatic Water for Injection — monograph and in-use stability guidance. USP-NF. (See institutional access.) https://doi.org/10.4135/9781412963855.n1200
- Wang, W. (1999). Instability, stabilization, and formulation of liquid protein pharmaceuticals. International Journal of Pharmaceutics, 185(2), 129–188. https://doi.org/10.1016/s0378-5173(99)00152-0
The arithmetic needs no citation; the diluent and stability guidance does.