--- title: "How to Reconstitute a Peptide Vial | Primara Labs" url: https://www.primaralabs.com/resources/how-to-reconstitute-a-peptide-vial source: Primara Labs, markdown mirror of the HTML page --- # How to reconstitute a lyophilized peptide vial Reconstituting a lyophilized peptide vial means adding a measured volume of bacteriostatic water to the dry powder so it returns to solution. The short version: wipe both stoppers with alcohol, use a new sterile syringe, run the water slowly down the inside of the vial, swirl until clear, then write the date and the concentration on the label. By Primara Labs team ยท Updated 24 September 2026 ## Materials - The sealed peptide vial, with its batch number readable. - [Bacteriostatic water](https://www.primaralabs.com/marketplace/bac-water-3ml), the preserved diluent made for vials that are drawn from more than once\[4\]. Why it and not plain sterile water is covered in [bacteriostatic water vs sterile water](https://www.primaralabs.com/resources/bacteriostatic-water-vs-sterile-water). - A new, sealed sterile syringe for each time a needle goes into a vial. - Alcohol prep pads, a clean flat surface, and a pen or label for the vial. Every order ships with bacteriostatic water, insulin syringes, alcohol pads and a reconstitution syringe, included rather than sold separately. ## Clean technique Wash and dry your hands and clear the work surface. CDC's safe injection guidance says to disinfect the rubber stopper of a medication vial with alcohol before piercing it, and to enter a vial with a new needle and a new syringe every time\[1\]. Wipe the stopper of the peptide vial and of the water vial, let the alcohol dry, and do not touch the stoppers afterwards. ## Choose the volume The volume of water sets the concentration and nothing else: milligrams in the vial divided by millilitres of water gives milligrams per millilitre. 5 mg in 2 mL gives 2.5 mg/mL. The same 5 mg in 1 mL gives 5 mg/mL. More water makes a weaker solution that is spread across more syringe marks, which makes small volumes easier to measure. The [reconstitution calculator](https://www.primaralabs.com/tools/peptide-calculator) does this arithmetic for any vial and water volume you enter and shows it on a syringe scale. ## Add the water down the wall Draw the chosen volume of bacteriostatic water into the syringe. Push the needle through the centre of the peptide vial's stopper, tilt the vial, and aim the stream at the inside of the glass rather than at the powder. Press the plunger slowly so the water runs down the wall and settles over the cake instead of blasting it. Withdraw the needle and discard the syringe. ## Swirl, do not shake Swirl the vial gently or roll it between your palms until the powder has dissolved. The US instructions for tesamorelin, a lyophilized peptide medicine, say to move the vial in a circle to mix and not to shake it, and not to use the solution if it is cloudy, coloured or has particles in it\[2\]. Shaking whips air into the solution and can damage the peptide. If a haze or undissolved cake remains after gentle swirling, see the in-depth guide to [cloudy vials](https://www.philippinespeptides.com/guides/peptide-cloudy-wont-dissolve) before deciding what to do. ## Label and store Write two things on the vial: the date you added the water and the concentration you made, for example "24 Sep, 2.5 mg/mL". CDC guidance, citing USP chapter 797, is that a multi-dose vial is dated when it is first opened and discarded within 28 days unless the manufacturer states another date\[3\]. How long a particular reconstituted peptide stays stable is compound-specific: follow the lab report or product label. Then put the vial in the refrigerator; the [storage guide](https://www.primaralabs.com/resources/storing-peptides) covers temperatures, light and freezing. Supplied for laboratory research use only. Not for human consumption. Nothing on this page is medical advice, and nothing here suggests an amount, a frequency or a protocol for any compound. ## Go deeper - [The full reconstitution walkthrough](https://www.primaralabs.com/blog/how-to-reconstitute-peptides) - [Reconstitution math, worked examples](https://www.primaralabs.com/blog/peptide-reconstitution-math) - [How much bacteriostatic water per vial](https://www.primaralabs.com/blog/how-much-bac-water-per-vial) - [Cloudy peptide vial: what it means, on philippinespeptides.com](https://www.philippinespeptides.com/guides/peptide-cloudy-wont-dissolve) ## Related products - [BAC Water 3ml](https://www.primaralabs.com/marketplace/bac-water-3ml) - [Retatrutide 15mg](https://www.primaralabs.com/marketplace/retatrutide) - [Tirzepatide 15mg](https://www.primaralabs.com/marketplace/tirzepatide-15mg) - [BPC-157 20mg](https://www.primaralabs.com/marketplace/bpc-157-20mg) ## Sources 1. [Standard Precautions: safe injection practices](https://www.cdc.gov/dental-infection-control/hcp/summary/standard-precautions.html). US Centers for Disease Control and Prevention. Cited for alcohol on the rubber stopper before piercing; a new needle and syringe for every entry into a vial. Checked 24 September 2026. 2. [EGRIFTA WR (tesamorelin) for injection: US label and instructions for use](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=839334d3-8c1d-4c26-9036-2ab524a6ea75). DailyMed, US National Library of Medicine. Cited for swirl, do not shake; appearance; light; freezing; discard periods on one labelled peptide medicine. Checked 24 September 2026. 3. [Preventing Unsafe Injection Practices](https://www.cdc.gov/injection-safety/hcp/clinical-safety/index.html). US Centers for Disease Control and Prevention. Cited for dating an opened multi-dose vial and the 28-day default, citing USP chapter 797. Checked 24 September 2026. 4. [Bacteriostatic Water for Injection, USP: prescribing information (Hospira)](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=87d6e9dc-fe3b-4593-ac9a-d7493d1959c7). DailyMed, US National Library of Medicine. Cited for benzyl alcohol content, multiple-dose container, label storage and warnings. Checked 24 September 2026.