About Recondraw
A free calculator that turns a peptide vial, the water you add and the syringe or pen you use into exact units, clicks and milligrams.
Medical disclaimer
Recondraw is a calculator and reference. It does not recommend doses, compounds or treatments, and it is not medical advice. Many compounds listed here are sold for research only and are not approved for human use where you live. Check every result against the markings on your own syringe or pen, and follow the guidance of a licensed clinician.
Vial sizes are common supplier catalog sizes. Your supplier’s label is the source of truth.
Privacy
Recondraw has no analytics, no ads and no third-party scripts or fonts. Every calculation runs in your browser, and your settings, shelf and dose log are saved in your browser’s storage on this device.
Sync is optional. If you turn it on, Recondraw stores a passkey’s public key, a session cookie that keeps you signed in, and your shelf encrypted on your device with a key the server never sees. There is no email address or name. You can delete everything from the shelf page at any time.
Install it as an app
Recondraw works offline once you’ve opened it. On Android and desktop Chrome or Edge, use Install app in the header or your browser menu. On iPhone and iPad, open it in Safari, tap Share, then Add to Home Screen.
Support and contact
Recondraw is free, with no ads and no tracking. If it saves you time, you can buy me a coffee to help keep it running.
Support me on Ko-fiIdeas, corrections or a peptide that’s missing? Email support@recondraw.com.
Sources
- Nest Scientific: how dosing works with injection pens
- Nest Scientific: injection pen buying guide
- Ypsomed: reusable pen platform (dose increments)
- Insulin syringe sizing: 0.3, 0.5 and 1 mL barrels
- Low dead space syringe (Wikipedia)
- Harm Reduction Journal (2018): dead space of detachable needles
- W3C WebAuthn: PRF extension (used to encrypt synced data)
- FITTER expert recommendations on injection technique (diaTribe summary)
- BD: injection technique for different needle lengths
- MedlinePlus: giving a subcutaneous injection
- UW Medicine: how to give yourself a subcutaneous injection
- UMass Memorial Health: giving a subcutaneous injection
- Lilly Medical: tips for under-the-skin injection
- Pfizer: Bacteriostatic Water for Injection, USP (prescribing information)
- Pfizer: Sterile Water for Injection, USP (prescribing information)
- CDC: preventing unsafe injection practices (multi-dose vials)
- University of Minnesota: U-100 and U-40 insulin syringes
- International unit (Wikipedia)