TL;DR: Sermorelin is registered here in 2mg, 5mg and 10mg vials. At PeptiMap’s reference volumes — 2mL, 2.5mL and 2mL of bacteriostatic water — those land on 1 mg/mL, 2 mg/mL and 5 mg/mL, or 10, 20 and 50 mcg per unit on a U-100 syringe. A 200 mcg draw is therefore 20 units from the 2mg vial, 10 from the 5mg and just 4 from the 10mg. Our EU price index carries two sermorelin rows — 2mg at €22.00 and 5mg at €32.00 — and no 10mg price at all, so we won’t quote one. The sermorelin calculator will redo any of it for a volume you prefer.
What the three vials actually are
Sermorelin is the 1-29 fragment of growth hormone releasing hormone — a GHRH analog, not a ghrelin-receptor secretagogue. For the receptor-level story, what is sermorelin covers it; this piece is only about the numbers, because that explainer deliberately carries none.
Three sizes are registered and all three resolve: the sermorelin 2mg page, the 5mg page and the 10mg page. Each carries its own reference reconstitution volume, and they are not on a common ruler.
That is the assumption everything rests on: a U-100 insulin syringe, where 1 unit = 0.01 mL. Swap to a U-40 barrel and none of these figures carry over.
The two formulas that drive every number
Everything in this article is these two lines, applied repeatedly.
mg/mL = vial strength (mg) ÷ BAC water added (mL)
mcg per unit = (mg/mL × 1000) ÷ 100
Worked example, 2mg vial with 2mL:
- Concentration: 2 ÷ 2 = 1 mg/mL = 1000 mcg/mL
- Per unit: 1000 ÷ 100 = 10 mcg per unit
- A 200 mcg draw: 200 ÷ 10 = 20 units = 0.20 mL
Worked example, 5mg vial with 2.5mL:
- Concentration: 5 ÷ 2.5 = 2 mg/mL = 2000 mcg/mL
- Per unit: 2000 ÷ 100 = 20 mcg per unit
- The same 200 mcg draw: 200 ÷ 20 = 10 units = 0.10 mL
20 units on a U-100 syringe = 0.20 mL = 200 mcg when the vial sits at 1 mg/mL (2mg reconstituted in 2mL).
Doubling the vial while barely changing the water is what makes the 10mg awkward: 10 ÷ 2 = 5 mg/mL, or 50 mcg per unit mark, turning a 200 mcg dose into a 4-unit draw — a lot of dose on very little plunger travel.
Sermorelin dosing chart by vial size
Three tables, one per vial, each at its catalogue reference volume. Doses per vial assumes full recovery and no waste.
2mg vial + 2mL BAC water = 1 mg/mL (10 mcg per unit)
| Target dose | Draw volume | U-100 units | Doses per vial |
|---|---|---|---|
| 100 mcg | 0.10 mL | 10 units | 20 |
| 200 mcg | 0.20 mL | 20 units | 10 |
| 250 mcg | 0.25 mL | 25 units | 8 |
| 300 mcg | 0.30 mL | 30 units | 6.67 |
| 500 mcg | 0.50 mL | 50 units | 4 |
| 1 mg | 1.00 mL | 100 units | 2 |
5mg vial + 2.5mL BAC water = 2 mg/mL (20 mcg per unit)
| Target dose | Draw volume | U-100 units | Doses per vial |
|---|---|---|---|
| 100 mcg | 0.05 mL | 5 units | 50 |
| 200 mcg | 0.10 mL | 10 units | 25 |
| 250 mcg | 0.125 mL | 12.5 units | 20 |
| 300 mcg | 0.15 mL | 15 units | 16.67 |
| 500 mcg | 0.25 mL | 25 units | 10 |
| 1 mg | 0.50 mL | 50 units | 5 |
10mg vial + 2mL BAC water = 5 mg/mL (50 mcg per unit)
| Target dose | Draw volume | U-100 units | Doses per vial |
|---|---|---|---|
| 100 mcg | 0.02 mL | 2 units | 100 |
| 200 mcg | 0.04 mL | 4 units | 50 |
| 250 mcg | 0.05 mL | 5 units | 40 |
| 300 mcg | 0.06 mL | 6 units | 33.3 |
| 500 mcg | 0.10 mL | 10 units | 20 |
| 1 mg | 0.20 mL | 20 units | 10 |
Two things jump out. The 250 mcg row on the 5mg vial lands on 12.5 units, a half-unit no insulin barrel marks. And every row on the 10mg vial is cramped into the first six units of a hundred-unit scale. Both are solved the same way: change the water, not the dose.
Pick the volume that makes your dose land on a whole unit
You are not locked to the reference volumes. More water gives finer resolution; less water gives compact draws. The peptide is identical either way — you are only choosing the ruler, the same principle as the general reconstitution chart.
| Vial | BAC water | Concentration | mcg per unit | 200 mcg draw |
|---|---|---|---|---|
| 2mg | 1 mL | 2 mg/mL | 20 mcg | 10 units |
| 2mg | 2 mL | 1 mg/mL | 10 mcg | 20 units |
| 2mg | 2.5 mL | 0.8 mg/mL | 8 mcg | 25 units |
| 5mg | 2 mL | 2.5 mg/mL | 25 mcg | 8 units |
| 5mg | 2.5 mL | 2 mg/mL | 20 mcg | 10 units |
| 5mg | 5 mL | 1 mg/mL | 10 mcg | 20 units |
| 10mg | 2 mL | 5 mg/mL | 50 mcg | 4 units |
| 10mg | 4 mL | 2.5 mg/mL | 25 mcg | 8 units |
| 10mg | 5 mL | 2 mg/mL | 20 mcg | 10 units |
That also fixes the half-unit problem. At 2 mg/mL a 250 mcg dose is 12.5 units; at 1 mg/mL it is a clean 25. If a target dose keeps coming out fractional, adjust the diluent rather than squinting at the plunger.
What a dose actually costs
Our index carries two sermorelin prices, both listed EU research-supply figures from the price index snapshot rather than literature values.
Listed EU price-index figures: 2mg at EUR 22.00, 5mg at EUR 32.00. The 10mg size has no listed price in our dataset.
Stepping from 2mg to 5mg cuts cost per mg by 41.8%. Translated into doses, at 200 mcg:
- 2mg vial: 10 doses per vial, €22.00 ÷ 10 = €2.20 per dose
- 5mg vial: 25 doses per vial, €32.00 ÷ 25 = €1.28 per dose
At 300 mcg it is €3.30 versus €1.92; at 500 mcg, €5.50 versus €3.20. What matters more is that the ladder stops there. With no 10mg row to price against, ten milligrams assembled from listed rows is two 5mg vials at €64.00 — €6.40/mg, exactly the same rate, no third-rung discount at all.
For contrast, tesamorelin — a fellow GHRH analog, and the one carrying the deepest ladder in our index — runs €35.00 for 5mg (€7.00/mg), €49.00 for 10mg (€4.90/mg) and €85.00 for 20mg (€4.25/mg): a 30.0% drop, then a further 13.3%. Roughly the shape to expect if sermorelin ever gains a genuine 10mg line: a projection from a sibling, not a price. The cost calculator will run your own figures.
Doses per vial versus the fridge window
Reconstituted sermorelin holds roughly 3-4 weeks at 2-8 °C on the 5mg and 10mg pages, 4-6 weeks on the 2mg page. That window, not the dose count, usually decides which size makes sense.
| Vial | Recon volume | Doses at 200 mcg | Days at 200 mcg daily | Doses at 500 mcg |
|---|---|---|---|---|
| 2mg | 2 mL | 10 | 10 | 4 |
| 5mg | 2.5 mL | 25 | 25 | 10 |
| 10mg | 2 mL | 50 | 50 | 20 |
At 200 mcg daily the 5mg vial runs 25 days — right inside the 3-4 week window, and the reason it is the default size here. The 2mg empties in ten days, so you are opening vials constantly. The 10mg runs fifty days at the same dose, so roughly half would pass the window before it was drawn; that format only earns its size at 500 mcg or above, or split and reconstituted in stages.
Why the GHRH shape is not the secretagogue shape
This is where sermorelin diverges from the ipamorelin and GHRP family, and it changes what the vial math is for.
Sermorelin binds the GHRH receptor and its label PK is brutally short: elimination half-life 11-12 minutes, mean absolute subcutaneous bioavailability about 6%. Ipamorelin works through the ghrelin receptor (GHS-R1a) at a measured 2 hours — roughly ten times longer. The full spread sits on the half-life chart.
The practical consequence: sermorelin’s dosing shape is about timing, not accumulation. Nothing lingers, so nothing stacks — a two-hour tail tolerates loose scheduling, an eleven-minute one does not. The ipamorelin dosing and timing piece works the same problem from the other side of the receptor. The 6% subcutaneous figure explains the rest: it is why sermorelin reference doses sit in hundreds of micrograms, the same band as the GHRPs despite very different pharmacology.
For the oral end of the comparison, MK-677 versus GH secretagogues covers ibutamoren — not a peptide at all, and a half-life in hours rather than minutes. A third dosing shape again.
Hand the numbers to the calculator
None of this is worth re-deriving by hand every time the volume changes. Two tools do it:
- The sermorelin calculator takes vial strength, BAC volume and target dose and returns mg/mL, mcg per unit and the exact syringe mark.
- The general peptide calculator does the same for any compound, useful when you want two rulers side by side.
Frequently Asked Questions
How much BAC water do I add to a 5mg sermorelin vial?
2.5mL is the catalogue reference, giving 2 mg/mL and 20 mcg per unit — a 200 mcg dose is 10 units, or 0.10 mL. Using 5mL instead halves the concentration to 1 mg/mL and doubles every draw to 20 units, giving finer resolution on small doses.
How many units is 200 mcg of sermorelin?
Concentration decides, never the vial label. At 1 mg/mL (2mg in 2mL) it is 20 units; at 2 mg/mL (5mg in 2.5mL), 10 units; at 5 mg/mL (10mg in 2mL), only 4. All on a U-100 syringe where 1 unit is 0.01 mL.
Which sermorelin vial size is cheapest per mg?
Of the two sizes with a listed price, the 5mg at €32.00 works out to €6.40 per mg against €11.00 per mg for the 2mg at €22.00 — a 41.8% saving. There is no listed 10mg price in our index, so ten milligrams assembled from priced rows is simply two 5mg vials at the same €6.40 rate.
How many doses are in a 5mg sermorelin vial?
Twenty-five at 200 mcg, twenty at 250 mcg, about 16.7 at 300 mcg and ten at 500 mcg. At 200 mcg daily that is 25 days of draws, fitting neatly inside the 3-4 week reconstituted window.
Does sermorelin dosing work like ipamorelin dosing?
Not really. Sermorelin is a GHRH-receptor analog with an 11-12 minute elimination half-life; ipamorelin is a ghrelin-receptor agonist at around 2 hours. The milligram amounts look similar on paper, but the short half-life makes sermorelin’s schedule about timing rather than accumulation.
Why does my 10mg vial give such tiny draws?
Because its reference volume is 2mL, putting it at 5 mg/mL — 50 mcg on every unit mark, so a 200 mcg dose lands on 4 units. Reconstituting in 5mL drops it to 2 mg/mL and stretches the same dose to 10 units, far easier to measure.
References
- Serono Laboratories. “Geref (sermorelin acetate) for injection” — product label. Elimination half-life 11-12 minutes after intravenous or subcutaneous dosing; mean absolute subcutaneous bioavailability approximately 6%.
- Prakash A, Goa KL. “Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency.” BioDrugs, 1999;12(2):139-157.
- Corpas E, Harman SM, Piñeyro MA, et al. “Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men.” Journal of Clinical Endocrinology and Metabolism, 1992;75(2):530-535.
- Walker RF. “Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?” Clinical Interventions in Aging, 2006;1(4):307-308.
- Gobburu JV, Agersø H, Jusko WJ, Ynddal L. “Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.” Pharmaceutical Research, 1999;16(9):1412-1416.
- PeptiMap. “EU Peptide Price Index” — build-time snapshot of listed European research-supply pricing. The sermorelin and tesamorelin euro figures in this article come from that dataset, not from published literature.
This article is a research and educational reference only; sermorelin sold as a research peptide is not an approved medicine, this is not medical advice, and it is not for human consumption.