Peptide Safety 101: How to Reconstitute, Inject, and Store Peptides the Right Way

As interest in peptides grows, so do the questions:

What liquid should I use to reconstitute peptides?

How do I calculate my dose?

How long do reconstituted peptides last?

This guide covers the essentials you need to know—and includes our peptide reconstitution calculator and step-by-step video to make the process simple and stress-free.

What Are Peptides? 

Your body naturally produces peptides every day to carry out vital functions—healing injuries, building muscle, regulating mood, supporting metabolism, and much more.

Laboratory-synthesized peptides are nearly identical to those your body makes, but in more concentrated and targeted forms – allowing you to enhance specific processes like fat burning, recovery, cognitive performance, hormone regulation and more.

Because peptides are delicate by nature, they don’t stay stable for long in their liquid form. To preserve their integrity, they’re typically freeze-dried (lyophilized) into a powder. In this state, they can remain shelf stable for up to 2 years in a cool, dry place away from direct light. 

Peptides offer tremendous potential — but only if you treat them with the respect they deserve. That means learning how to mix correctly, inject safely, track your doses, store them right, and buy from a reputable source. The better your process, the better your outcomes.

What You’ll Need Before You Start

• Peptide vial (lyophilized powder)

• Bacteriostatic water

• Insulin syringes – I recommend the 1 mL size insulin syringe (29–31 gauge, ½” needle). You can get a .5mL or .3mL if you are working with small dosages. These can be purchased at any pharmacy or online.

• Alcohol prep pads

• Clean surface with good lighting

Once you’ve got your supplies ready, you can use our reconstitution calculator to figure out the exact amounts you’ll need—no math required.

Peptide Reconstitution Calculator

Peptide Vial Amount (mg): 2 mg 3 mg 5 mg 10 mg 15 mg Other Bacteriostatic Water (mL): 1 mL 2 mL 3 mL 5 mL Other What is the dose? (mcg/mg) 50 mcg 100 mcg 250 mcg 500 mcg 1 mg 2.5 mg 5 mg 10 mg Other

mg mcg

Syringe Size (mL): 30 units (.3mL) 50 units (.5mL) 100 units (1mL) Calculate

Result:

Reconstituting Peptides: How to Mix Them Properly

Most peptides arrive as a lyophilized (freeze-dried) powder. To make them ready for use, they must be reconstituted with a sterile liquid — a process called reconstitution.

What Liquid Should You Use?

• Bacteriostatic Water (BAC Water) – Also called Reconstitution Solution. This is the gold standard. It contains a tiny bit of benzyl alcohol to prevent bacterial growth.
• Sterile Water – OK for single-use vials. Not safe for long term storage because it does not contain an anti-microbial agent.
• DO NOT use tap, bottled, or distilled water — those aren’t sterile and will degrade the peptide.

Step-by-Step

1. Clean the rubber tops of the vials with an alcohol pad.
2. Draw the BAC Water with a clean syringe and inject it slowly into the vial—don’t blast the powder. You need to use at least 2 mL of Reconstitution Solution for every 10mg of peptide powder.
3. Let it dissolve naturally—swirl gently if its not fully dissolved, but don’t shake it.

Here is a step-by-step video to walk you through reconstituting a peptide vial from start to finish.

Storing Peptides the Right Way

Peptides are sensitive to temperature, light, and contamination— you must keep them in the right conditions for your peptides to stay stable, potent, and effective.

Before Reconstitution 

• Store your peptide vials sealed in the refrigerator or in a cool dark place like a cabinet.
• They remain stable in this state for 12 – 24 months
• Keep vials away from direct light and excess moisture

After Reconstitution (Once Mixed with BAC Water)

• Store in the refrigerator (at 36–46°F / 2–8°C)
• Use within 8 -12 weeks

How to Inject Peptides Safely: Using a Syringe or a Peptide Pen

Most peptides are injected just under the skin (a method called subcutaneous injection), and there are two main ways to do that: with an insulin syringe, or with a newer tool called a peptide pen.

Syringes are the most widely used and give you precise control over your dosage. Peptide pens, on the other hand, offer a nearly needle-free option that uses pressure to deliver the solution into the skin. They’re especially popular among beginners who want a gentler, simpler alternative to needles.

In this section, we’ll walk through how to use each method safely and correctly.

How to Inject Peptides with a Syringe (Subcutaneous Method)

Most research peptides are designed for subQ (subcutaneous) delivery—meaning they’re injected into the fatty layer just below the skin. This method is fast, low-pain, and highly effective for absorption.

You will need an alcohol prep pad and an insulin syringe. I recommend the 1mL size insulin syringe (29–31 gauge, ½” needle). You can get a .5mL or .3mL if you are working with small dosages. These can be purchased at any pharmacy or online.

Step-by-Step Injection

1. Clean the rubber top of your peptide vial with an alcohol pad.
2. Draw your dose from your reconstituted peptide vial using a sterile insulin syringe
3. Choose an injection site: lower belly (about 1–2 inches below the navel), upper thigh, or glute area.
4. Wipe off the site with an alcohol pad.
5. Pinch the skin, insert the needle at a 45–90° angle, and inject slowly.
6. Withdraw the needle, apply light pressure with a clean pad if needed—no need to massage.
7. Cap the syringe and dispose. Do not re-use the syringe.

Tips for Success

• Rotate injection sites to prevent irritation or lumps.
• Never reuse needles—always start sterile.
• If your skin stings or bleeds, you may have gone too deep—try a new spot next time.

Using the Peptide Pen: A Nearly Needle-Free Option for Injection

Some people prefer peptide pens, which automate the injection and use an ultra-fine needle. They can make dosing quicker and less intimidating, especially for beginners.

How the Peptide Pen Works

• Use a sterile syringe to draw the correct dose of reconstituted peptide solution and load it into the pen’s cartridge.
• When activated, the spring-loaded pen delivers the peptide under the skin through a fine needle, usually between 4–6mm long.
• The delivery is quick, and most people report only very mild pressure or a slight “snap” sensation—no sting or puncture.

Peptide Pen Safety Tips

• Follow the manufacturer’s instructions—each pen may differ slightly in loading and technique.
• Use the correct volume and settings to control how much peptide is released per click.
• Rotate injection sites to maintain healthy skin and ensure optimal peptide absorption.

Track Your Peptide Protocol Like A Pro

Tracking your peptide use isn’t just about staying organized—it’s how you find what dosage and schedule work best for your body.

Use a digital tracker, spreadsheet, journal, or app—whatever keeps you consistent. Here’s what to include:

• Peptide name (e.g. BPC-157, Semaglutide)
• Date & time of dose
• Amount taken (in mg or mcg)
• How you took it (syringe, pen, etc.)
• Injection site (Remember to rotate)
• Notes on how you feel—energy, sleep, mood, appetite, recovery, or any side effects

You can use a notebook, spreadsheet, or an app—whatever keeps you consistent. Over time, these records help you:

• Avoid mistakes like double-dosing or skipping doses

• Spot patterns in how your body responds

• Adjust more confidently if something needs fine-tuning

The better your notes, the faster you’ll learn what works, what doesn’t, and how to adjust your protocol for the best possible outcome.

Recommended Dosage Guides

For convenience and safety, always reference research-backed ranges and start conservatively. You can find full dosage protocols, contraindications, and suggested guidelines for the following peptides here:

• BPC-157: How it Works, Dosage and Side Effects
• TB-500: How it Works, Dosage and Side Effects
• Retatrutide: How it Works, Dosage and Side Effects
• PT-141: How it Works, Dosage and Side Effects
• Semaglutide: How it Works, Dosage and Side Effects
• CJC-1295: How it Works, Dosage and Side Effects

How to Source Peptides Safely

Not all peptides are created equal. And in today’s flooded online market, there’s a big difference between a research-grade compound and a mystery vial with a fancy label.

Red Flags to Watch Out For

• No certificate of analysis (COA) or third-party testing
• Websites promising miracle cures
• Ultra-low pricing that seems too good to be true (it probably is)

These are all signs the product could be underdosed, contaminated, mislabeled—or not even what it claims to be.

What to Look For Instead

When shopping for peptides, look for signs of transparency and legitimacy:

• cGMP-certified manufacturing (follows pharmaceutical-level cleanliness and quality standards)
• Third-party lab testing with purity results of 99% or higher
• Peptide companies that serve research professionals and labs
• Accessible COAs, batch tracking, and documentation