Retatrutide (5mg)

Retatrutide 5mg — the smallest reta vial, with a full reconstitution guide

This is the 5mg retatrutide vial at $99.99, the entry size in the range and the least material you can order. It holds five milligrams of lyophilised LY3437943, the peptide commonly shortened to reta.

Three situations call for this size: a first pilot before committing budget to a longer study, a short dose-response series consuming only a few milligrams, or validating handling and reconstitution procedure on an inexpensive vial before scaling up. Because it is the size most researchers meet first, this page carries the full reconstitution walkthrough for retatrutide rather than assuming prior familiarity.

Vials are filled from the same COA-verified production batches as every other size, so purity and identity do not change with vial size. All sizes are selectable from one listing on the main Retatrutide page.

What 5mg actually yields

Five milligrams is a small working quantity and worth dividing out before ordering.

• Five 1mg aliquots from one vial, with nothing left over.
• Ten 0.5mg aliquots, the usual split for a low-dose titration arm.
• Two 2mg aliquots plus a 1mg remainder, so 2mg divides awkwardly.

The whole vial is reconstituted at once and the solution holds 28 days refrigerated. 5mg is the one size where a single researcher can comfortably use the entire vial inside that window at almost any sensible aliquot size. That advantage disappears quickly as you move up the ladder, and it is the real reason to pay the per-mg premium here.

How to reconstitute retatrutide, step by step

1. Bring both to room temperature. Take the lyophilised vial and the bacteriostatic water out of refrigeration and let them equilibrate. Cold powder dissolves slowly and encourages over-agitation.
2. Swab both stoppers. Wipe the rubber septum on the peptide vial and the water vial with an alcohol swab and let them dry.
3. Draw the calculated volume. For a 5mg vial, 1.0 mL of bacteriostatic water gives 5 mg/mL. The table below covers the other common targets.
4. Run the water down the vial wall. Angle the needle so the stream hits the inside glass and runs onto the powder rather than striking it directly. A direct jet onto lyophilised peptide causes foaming and can shear the molecule.
5. Swirl, do not shake. Roll the vial gently between your fingers until the solution is completely clear. Full dissolution usually takes under a minute. Never invert and shake.
6. Inspect. The solution should be clear and free of visible particulate. Cloudiness or persistent solids means it has not fully dissolved.
7. Refrigerate immediately. Store at 2–8°C and use within 28 days. Label the vial with the reconstitution date.

Reconstitution volumes for a 5mg vial

Calculated for 5mg specifically. A U100 insulin syringe reads 100 units to the millilitre, so the unit figures below can be read straight off the barrel.

1.0 mL is the most common choice for a 5mg vial: a round 5 mg/mL, every aliquot inside a single 1mL syringe, and enough headroom that swirling is easy. Moving to 2.0 mL helps when the protocol calls for sub-milligram aliquots, because it pushes small volumes further up the barrel where they are easier to measure accurately.

One 10mL bottle of bacteriostatic water reconstitutes ten 5mg vials at 1.0 mL each. The reconstitution calculator will work out any concentration not listed.

Retatrutide 5mg price and cost per mg

$99.99 for 5mg is $20.00 per mg, the highest per-mg price in the range. That is the trade for the smallest commitment.

Moving from 5mg to 10mg cuts the per-mg cost by 20 percent; moving to the 60mg vial cuts it by just over half. The 5mg vial is worth the premium while a study is genuinely short or still unproven. Once you know you will consume more than about 10mg in total, the premium stops making sense and the 20mg or 30mg vial is the better buy.

Storing a 5mg vial

Sealed and lyophilised, store at 2–8°C for short-term holding or −20°C for long-term, protected from light and moisture, avoiding repeated freeze-thaw cycles.

Once reconstituted, keep the vial refrigerated at 2–8°C and use within 28 days. With only 5mg in the vial this window is rarely the limiting factor, which is not true of the larger sizes, so a 5mg vial can be reconstituted on arrival without planning the schedule around its expiry.

Reconstitution mistakes that cost you the vial

Most retatrutide lost in handling is lost at reconstitution rather than in storage, and almost always to one of the following.

• Injecting the water straight onto the powder. A direct jet foams the solution and mechanically shears the peptide. Angle the needle so the stream runs down the inside glass.
• Shaking to speed dissolution. Shaking denatures peptide at the air-liquid interface. A gentle roll between the fingers dissolves a 5mg vial in well under a minute.
• Reconstituting straight from the fridge. Cold powder dissolves slowly, which tempts over-agitation. Let both vials reach room temperature first.
• Using sterile water instead of bacteriostatic. Sterile water has no preservative, so the solution cannot be stored for the 28 day window. Bacteriostatic water contains 0.9 percent benzyl alcohol, which is what makes multi-draw storage possible.
• Not labelling the reconstitution date. The 28 day clock starts the moment water goes in, and an unlabelled vial is a vial you will eventually have to discard on doubt.
• Repeated freeze-thaw of reconstituted solution. Freezing after reconstitution is not a way to extend the window. Keep it at 2–8°C and work to the 28 days.

Specifications

Batch testing and COA

Every batch is independently tested by Janoshik Analytical. HPLC confirms purity at 99 percent or higher and mass spectrometry confirms the measured mass matches the expected weight of the 39-residue backbone, so identity is verified as well as purity. The batch number on your vial can be matched to its report in the COA library. Orders placed before 12pm are dispatched the same business day from Australian stock.

Other retatrutide sizes

Every retatrutide size Omega Peptides Australia stocks, with the per-mg cost of each. All sizes can also be selected from a single listing on the main Retatrutide page.

• Retatrutide 5mg — the smallest vial, and the page you are on, $99.99
• Retatrutide 10mg — the standard single vial, $16.00 per mg, $159.99
• Retatrutide 20mg — first bulk tier, $13.50 per mg, $269.99
• Retatrutide 30mg — established-protocol size, $12.00 per mg, $359.99
• Retatrutide 60mg — lowest cost per mg, $9.83 per mg, $589.99
• Retatrutide Box (10 x 10mg) — ten sealed vials, $11.00 per mg, $1,099.99

Background on the compound itself sits on the Retatrutide product page and in the retatrutide research guide, rather than being repeated on each size page.

Ordered with a 5mg vial

• Bacteriostatic water — one 10mL bottle covers ten 5mg vials at the standard 1.0 mL fill.
• Retatrutide Starter Kit — vial, water, syringes and swabs together if you are setting up from scratch.
• Tirzepatide — the dual GLP-1/GIP agonist most often run as a comparator arm alongside reta.

Frequently asked questions

How do you reconstitute retatrutide?
Bring the vial and bacteriostatic water to room temperature, swab both stoppers, then run the calculated volume of water down the inside wall of the vial so it flows onto the powder rather than striking it. Swirl gently until clear, never shake, then refrigerate at 2 to 8 degrees Celsius and use within 28 days. For a 5mg vial, 1.0 mL gives 5 mg/mL.

How much bacteriostatic water do I add to a 5mg vial?
1.0 mL is standard for a 5mg vial and gives 5 mg/mL, so a 1mg aliquot is 20 units on a U100 syringe. Use 0.5 mL for 10 mg/mL or 2.0 mL for 2.5 mg/mL if the protocol calls for sub-milligram aliquots.

How many doses are in a 5mg retatrutide vial?
Five 1mg aliquots, ten 0.5mg aliquots, or two 2mg aliquots with 1mg remaining. It is the only size a single researcher can reliably finish inside the 28 day reconstituted window at any aliquot size.

How much is retatrutide 5mg in Australia?
$99.99 for the 5mg vial, which is $20.00 per mg. That is the highest per-mg price in the range because it is the smallest quantity. The 60mg vial is cheapest at $9.83 per mg.

Why does the water have to run down the vial wall?
A direct jet of water onto lyophilised peptide causes foaming and mechanical shear, which can damage the molecule. Angling the needle so the stream runs down the glass and onto the powder avoids both, which is also why the vial is swirled rather than shaken.

Should I buy the 5mg vial or step up to 10mg?
Buy 5mg if the study is short, the protocol is unproven, or you are validating handling first. Step up once you know you will consume more than about 10mg, because the per-mg cost drops 20 percent at 10mg and keeps falling.

How long does a reconstituted 5mg vial last?
28 days refrigerated at 2 to 8 degrees Celsius. Because the vial holds only 5mg, most protocols consume it well inside that window, so expiry is rarely the constraint it becomes on a 30mg or 60mg vial.

Does the 5mg vial ship the same day in Australia?
Orders placed before 12pm are dispatched the same business day from Australian stock, with tracked domestic delivery in discreet unbranded packaging.

⚠ For in-vitro research and laboratory use only. Not for human or veterinary use.