Sermorelin Dosage Calculator: mcg to Units, Reconstitution & Tiny-Draw Precision

Reconstituting a sermorelin vial comes down to one number: how many units do you draw on the syringe? This calculator gives you that in one step. Enter how many milligrams are in your vial, how much bacteriostatic water you're adding, and your target microgram dose, and it returns the exact insulin-syringe mark, the concentration you've made, and how many doses the vial holds.

Sermorelin sits at the opposite end of the scale from a peptide like MOTS-c or TB-500: it's dosed in micrograms — community routines commonly use 200 to 500 mcg — out of a 5 mg or 10 mg vial that holds thousands of micrograms. That means a sermorelin draw is tiny, often only a handful of units, and the real challenge is reading such a small mark accurately. The calculator handles the microgram-to-units conversion and flags when a draw is too small to measure cleanly. If you run more than one compound, the general peptide dosage calculator covers the same math for any peptide, and sermorelin sits among the best peptides for muscle growth people reconstitute at home. Below the tool we walk through the math, why more water actually helps here, and what real sermorelin users mix.

Key Takeaways

• Two-step math (in mcg): concentration = vial mcg ÷ bac water mL, then units = (dose mcg ÷ concentration) × 100 on a U-100 syringe.
• Anchor example: a 5 mg vial + 2 mL of bacteriostatic water = 2,500 mcg/mL; a 250 mcg dose = 0.1 mL = 10 units, and the vial yields 20 doses.
• Sermorelin draws are very small. Our usage data shows a median draw of about 6 units, so reading the mark precisely matters more than overflow.
• More water = a larger, easier-to-read draw. This is the reverse of milligram-dosed peptides: extra bacteriostatic water enlarges a tiny sermorelin draw onto clearer marks. A U-50 syringe helps most of all.
• One vial is many doses. At ~250 mcg, a 5 mg vial holds about 20 doses, so cost per dose is low.
• Not a marketed drug. The former Geref brand is discontinued in the US; research-grade sermorelin is unapproved. Treat every figure as calculation context, not advice.

How do you calculate a sermorelin dose?

Sermorelin reconstitution is two steps, both in micrograms: work out the vial's concentration, then convert your microgram dose into a volume you can read on the syringe. The units you draw are simply that volume on the insulin scale.

In plain arithmetic, keeping everything in micrograms:

1. Concentration (mcg/mL) = vial mcg ÷ bac water mL. A 5 mg vial is 5,000 mcg; in 2 mL that's 5,000 ÷ 2 = 2,500 mcg/mL.
2. Volume (mL) = dose mcg ÷ concentration. A 250 mcg dose at 2,500 mcg/mL is 250 ÷ 2,500 = 0.1 mL.
3. Units = volume × 100 on a U-100 syringe (100 units = 1 mL). So 0.1 mL = 10 units.

Collapsed into the single formula the calculator runs:

units = (dose mcg ÷ (vial mcg ÷ bac water mL)) × 100 = dose mcg × bac water mL ÷ vial mcg × 100

Sanity-check our example: 250 × 2 ÷ 5,000 × 100 = 10 units. For doses per vial, divide the vial's micrograms by your dose: 5,000 mcg ÷ 250 mcg = 20 doses.

Our take: The whole difficulty with sermorelin is the opposite of a milligram peptide. There's no overflow risk — a full dose is a sliver of the barrel. The risk is reading a 6-to-10-unit draw accurately, where being off by a single unit is a meaningful percentage of the dose. So the levers that matter for sermorelin are concentration (use enough water to spread the draw onto readable marks) and syringe choice (a U-50 doubles the spacing of the marks). The sections below are about precision, not headroom.

Why are sermorelin draws so small, and what do real users mix?

Because a sermorelin dose (a few hundred micrograms) is a tiny fraction of the thousands of micrograms in the vial, the volume you draw is small — usually well under 15 units — so every reconstitution choice is about making that small draw readable. Concentration is the lever.

A 5 mg vial holds 5,000 mcg. Even a 500 mcg dose is one-tenth of it, and a 200 mcg dose is one-twenty-fifth. The draw shrinks with the dose and grows with the water, which is why the water volume you pick is really a readability decision. Because ProtocolPlus tracks reconstitutions, we can show the vial-strength × water-volume combinations real sermorelin users log — and unlike the milligram peptides, the crowd leans toward more water.

The pattern: 2 mL is the dominant water choice across both vial sizes. A 5 mg vial in 2 mL gives 2,500 mcg/mL, where a 250 mcg dose is a readable 10 units; a 10 mg vial in 2 mL gives 5,000 mcg/mL, where the same dose is a tighter 5 units. People reach for 2 mL precisely because 1 mL would shrink an already-small draw down toward the unreadable end of the scale.

How much bacteriostatic water should you add to sermorelin?

With sermorelin, lean toward more water (commonly 2 mL on a 5 mg vial) — because a larger volume spreads your few-hundred-microgram dose across more units, making the draw easier to measure accurately. This is the exact reverse of a milligram-dosed peptide.

The trade-off runs opposite to MOTS-c or TB-500. There, more water overflows a large draw; here, more water rescues a tiny one. A 250 mcg dose is just 5 units at 5,000 mcg/mL (5 mg in 1 mL) but a more comfortable 10 units at 2,500 mcg/mL (5 mg in 2 mL). The only practical ceiling on water is the vial's volume and how long the solution stays good — there's no overflow concern, since even a 500 mcg dose on a dilute vial is well under one syringe.

A worked walkthrough: choosing water for a readable draw

Say you have a 5 mg vial and your dose is 250 mcg. Run the candidate water volumes and watch the draw size:

• 1 mL → 5,000 mcg/mL. 250 mcg = 5 units. Small and easy to misread by a unit.
• 2 mL → 2,500 mcg/mL. 250 mcg = 10 units. Comfortable on a U-100 barrel.
• 3 mL → 1,667 mcg/mL. 250 mcg = 15 units. Even easier to read, if the vial holds the volume.

For sermorelin the winner is usually the higher practical water volume, the reverse of a milligram-dosed peptide. If your dose is small (say 100–150 mcg) and the draw still lands under 3 units, switch to a U-50 syringe, whose marks are twice as far apart, before adding still more water.

How do you convert sermorelin mcg to insulin units?

Convert by dividing your microgram dose by the vial's mcg-per-mL concentration to get millilitres, then multiply by 100 for U-100 units — the calculator does it instantly, but the shortcut is that at 2,500 mcg/mL, every 25 mcg is one unit. Units measure liquid volume, not micrograms of sermorelin.

The conversion depends entirely on your concentration, which is why a unit count from someone else's vial is meaningless for yours. Here's a 250 mcg dose expressed across the common concentrations, so you can see how the unit mark moves:

Read down the 100 mcg column: a small dose can be just 2 units on a strong vial — exactly where the calculator raises a low-precision flag and suggests more water or a U-50 syringe. Read across the 5 mg + 2 mL row for the most common setup: 100, 250, and 500 mcg land on a clean 4, 10, and 20 units.

Reading tiny sermorelin draws: U-100 versus U-50

On a U-100 syringe 100 units = 1 mL, but for sermorelin's small draws a U-50 (50 units = 0.5 mL) spaces the same volume across marks that are twice as far apart — easier to hit accurately. The "units" you read are always a measure of volume.

Across our tracked sermorelin doses the median draw is just 6 units, with most doses falling under 15. At that scale, syringe choice is the biggest precision lever you have.

The distribution hugs the low end of the barrel — the mirror image of a milligram peptide, whose draws pile up at the 100-unit wall. Three calibrations exist (U-100, U-50, U-40); for sermorelin, a U-50 0.3 mL barrel is often the better tool because it stretches a 5-to-15-unit draw across more readable spacing. Always confirm which syringe you're holding, since a unit means a different volume on each.

Sermorelin reconstitution chart: units by vial and dose

This chart shows the concentration each vial makes at the common water volumes and the U-100 units to draw, so you can pick a setup that lands your dose on a readable mark. For any other setup, use the calculator.

The most readable setups for a typical 200–300 mcg dose are the more dilute ones (5 mg + 2 mL, or 10 mg + 3 mL), which lift the draw into the 6-to-12-unit range. The most-searched single conversions, for a quick sanity check:

• 200 mcg sermorelin on a 2,500 mcg/mL vial = 0.08 mL = 8 units; on a 5,000 mcg/mL vial = 4 units.
• 300 mcg sermorelin on a 2,500 mcg/mL vial = 0.12 mL = 12 units.
• 500 mcg sermorelin on a 2,500 mcg/mL vial = 0.2 mL = 20 units.

How many sermorelin doses are in a vial, and what does each cost?

Doses per vial is vial micrograms ÷ your dose — and because sermorelin doses are small, a single vial holds many. Dividing the vial price by that number gives a true cost per dose.

A 5 mg (5,000 mcg) vial at a 250 mcg dose yields 20 doses; at 200 mcg it's 25. That's the opposite of a milligram peptide, so sermorelin is cheap per dose despite daily use. Across our tracked sermorelin vials the median works out to roughly 25 doses per completed vial at about $1.60 per dose.

For a full schedule rather than a single calculation, see our sermorelin dosing and protocol guide.

mcg, mg, units, and mL: keeping the four numbers straight

Micrograms measure the sermorelin; millilitres and units measure the liquid you draw. The dangerous slip is reading a microgram dose as if it were milligrams — a 1,000× error in the wrong direction. Keep the families separate and the math is easy.

Sermorelin is dosed in micrograms (200–500 mcg), like CJC-1295 or ipamorelin, so if you switch from a milligram peptide such as MOTS-c, watch the unit. 1 mg = 1,000 mcg. Here is a 250 mcg dose expressed four ways on a 2,500 mcg/mL vial, one quantity wearing four labels:

Why concentration is the number that actually matters

Concentration (mcg/mL) is the hinge of every sermorelin calculation — and for sermorelin it's what decides whether your tiny dose lands on a readable mark. It connects the micrograms in the vial to the units on the syringe.

Concentration is an exchange rate between micrograms of sermorelin and millilitres of liquid. A 2,500 mcg/mL vial trades every 1 mL for 2,500 mcg; your dose occupies a volume set by that rate, and the syringe scale turns it into a unit mark. Make the vial weaker (more water) and the same dose occupies more volume — more units, and an easier read. That's why, for sermorelin, concentration choice is mostly a readability choice.

It's also why you can never compare unit numbers across reconstitutions. "Draw 10 units" means 250 mcg on a 2,500 mcg/mL vial but 500 mcg on a 5,000 mcg/mL vial — double. Every unit instruction online is valid only for that exact vial and water volume.

A note on bedtime timing

Sermorelin is a GHRH analog meant to prompt the body's own growth-hormone pulse, and that pulse is largest during early sleep — which is why clinic and community routines usually place the dose at bedtime, on an empty stomach. The calculator doesn't decide timing; it only converts whichever per-injection dose you choose into a unit mark. Whether to dose nightly, cycle five days on and two off, or pair it with another secretagogue is a protocol question covered in our sermorelin dosing and protocol guide: keep each individual injection as the number you run through the tool.

How to reconstitute sermorelin, step by step

Add the bacteriostatic water slowly down the vial wall, swirl gently until clear, and never shake. The peptide is delicate, and rough mixing degrades it before your first dose.

1. Calculate first. Use the tool above to set your water volume and target unit mark, and check the precision flag — with sermorelin, aim for a draw you can read cleanly.
2. Room temperature, then swab both stoppers with a fresh alcohol swab.
3. Draw your measured water into a reconstitution syringe.
4. Add slowly down the wall of the sermorelin vial, onto the glass rather than the powder.
5. Swirl, don't shake until the solution is completely clear.
6. Inspect. Clear and particle-free, or don't use it.
7. Label and refrigerate at 2–8 °C, then dose at the unit mark the calculator gave you.

Reconstitution troubleshooting

• The draw is only a couple of units. Not an error — your concentration is high for such a small dose. Use more bacteriostatic water, or switch to a U-50 syringe for finer marks.
• The powder won't fully dissolve. Give it a few minutes and keep swirling gently; warmth helps. A vial that stays cloudy or shows particles shouldn't be used.
• Foam or a hard vacuum pull. Some vials are under vacuum; vent briefly with an empty needle or add the water slowly down the wall.

Common sermorelin reconstitution mistakes

• Using too little water. With sermorelin, that shrinks the draw toward the unreadable end — usually you want more.
• Confusing mcg with mg. A 1,000× error; sermorelin is micrograms.
• Reading "units" as micrograms. Units are a volume; always convert through the calculator.
• Copying someone else's unit count. Valid only for that person's exact concentration.
• Wrong syringe (a U-100 barrel makes a tiny draw harder to read than a U-50), and not labeling the date.

Sermorelin vial sizes, supplies, and water

Sermorelin usually comes in 5 mg or 10 mg vials, and either works fine — the vial size mostly changes how many doses you get and the concentration you'll mix to. Pick the water volume that lands your dose on a readable mark.

• 5 mg — common; in 2 mL it's 2,500 mcg/mL, where a 250 mcg dose is a clean 10 units and the vial gives about 20 doses.
• 10 mg — in 2 mL it's 5,000 mcg/mL (tighter draws), or in 3–4 mL it dilutes back to readable marks with about 40 doses per vial.

A quick supplies checklist: the lyophilized sermorelin vial, bacteriostatic water (sterile water with 0.9% benzyl alcohol) as the diluent, a reconstitution syringe (1–3 mL), a U-100 or U-50 insulin syringe (a U-50 reads small draws better), alcohol swabs, and a marker for the date. Use bacteriostatic — not preservative-free or non-injectable — water for a multi-dose vial.

How long does reconstituted sermorelin last?

Once mixed, sermorelin is far less stable than the dry powder, and there's no validated shelf life — the common ~28-day refrigerated convention is a usage habit, not data. Judge by appearance, not just the calendar.

Peptides in solution degrade through hydrolysis, deamidation, oxidation, and aggregation, sped up by heat, light, and agitation, so a mixed vial belongs in the refrigerator at 2–8 °C, kept dark, and never frozen. Because a sermorelin vial holds many small doses, it often outlasts a single month of nightly use; in our usage data the median reconstituted vial is finished in about 20 days. Discard any vial that turns cloudy, changes color, or shows particles. For the deeper science, see our peptide storage and stability guide.

What the evidence says about sermorelin dosing

Sermorelin was once an approved drug, so it has a real clinical history — but its modern community dosing figures are still convention rather than a current label, because the marketed product was discontinued. We give the figures only so you know what to enter into the calculator.

Sermorelin is a synthetic analog of the first 29 amino acids of growth-hormone-releasing hormone (GHRH 1-29), the fragment that carries its activity. Its acetate salt was marketed as Geref, FDA-approved in 1997 for assessing and treating growth-hormone deficiency, and was reviewed in the clinical literature of that era (PubMed, 1999, Prakash & Goa, "Sermorelin: A Review of its Use in the Diagnosis and Treatment of Children with Idiopathic Growth Hormone Deficiency," BioDrugs, retrieved 2026-06-16). The brand was later pulled from the US market around 2008; the FDA subsequently determined that Geref was not withdrawn for reasons of safety or effectiveness — a regulatory record that matters because it means the discontinuation was commercial, not a safety signal (Federal Register, 2013, "Determination That GEREF (Sermorelin Acetate) Injection Was Not Withdrawn From Sale for Reasons of Safety or Effectiveness", retrieved 2026-06-16). GHRH analogs as a class continue to be studied as growth-hormone secretagogues (Wiley, 2020, "Growth hormone secretagogues: history, mechanism of action and clinical development," JCSM Rapid Communications, retrieved 2026-06-16). Today there is no marketed sermorelin product in the US; research-grade and compounded material is unapproved, and the common 200–500 mcg once-nightly figure is a clinic and community convention, not a validated dose.

How precise does your sermorelin draw need to be?

Because sermorelin draws are small (often 5–12 units), precision matters more than for any milligram peptide: at 2,500 mcg/mL, one U-100 unit is 25 mcg, so being off by a single unit on a 10-unit draw shifts a 250 mcg dose by 10 percent. That's the whole argument for using enough water to spread the draw and, for the smallest doses, a U-50 syringe whose marks are twice as far apart.

Frequently asked questions

Sources

Factual claims (regulatory history, peptide identity) are sourced below. Dose values in examples are illustrative, not recommendations; the 200–500 mcg figures are clinic and community convention, not a current approved label. ProtocolPlus usage figures are first-party app data.

1. PubMed (1999) — Prakash A, Goa KL, Sermorelin: A Review of its Use in the Diagnosis and Treatment of Children with Idiopathic Growth Hormone Deficiency, BioDrugs 12(2):139–157. https://pubmed.ncbi.nlm.nih.gov/18031173/ — retrieved 2026-06-16.
2. Federal Register (2013) — Determination That GEREF (Sermorelin Acetate) Injection Was Not Withdrawn From Sale for Reasons of Safety or Effectiveness. https://www.federalregister.gov/documents/2013/03/04/2013-04827/ — retrieved 2026-06-16.
3. Wiley / JCSM Rapid Communications (2020) — Growth hormone secretagogues: history, mechanism of action and clinical development. https://onlinelibrary.wiley.com/doi/full/10.1002/rco2.9 — retrieved 2026-06-16.
4. Springer / Reviews in Endocrine and Metabolic Disorders (2024) — GHRH analogs: therapeutic advances. https://link.springer.com/article/10.1007/s11154-024-09929-2 — retrieved 2026-06-16.

About this guide. Written by Jordan Vance, peptide and biohacking researcher (placeholder, replace before publish), and medically reviewed by Dr. Maya Ellison, MD, biochemistry (placeholder, replace before publish), for the ProtocolPlus Research Team. This calculator and article are educational and not medical advice.