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Frequently asked questions

Quick answers to the most common questions about BAC water, peptide reconstitution, and how the calculators work. Can't find what you're looking for? Contact us.

New to BAC water? Start at the top

The questions below cover what BAC water is, how much to add, storage and refrigeration, and whether you need a prescription. For exact numbers, our Plan Builder does the math automatically.

Reconstituted peptide storage rulesReconstituted peptide storage rules: Fridge, Keep mixed vials cold, per your product's instructions; Discard date, Follow the instructions that came with your product; Dark, Keep in the box or foil; Freezing, Can damage many peptides. Check your instructions. Storing reconstituted peptides Four rules that keep a mixed vial usable for its full shelf life. Fridge Keep mixed vials cold,per your product's Discard date Follow the instructionsthat came with your Dark Keep in the box or foil Freezing Can damage manypeptides. Check your
Storage at a glance: refrigerate a mixed vial, keep it dark, and follow the discard date in your product's instructions.
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BAC water is sterile water with a small amount of preservative added. The preservative is called benzyl alcohol (a germ-fighting ingredient). It stops germs from growing in the water. This lets you use the same bottle many times over several weeks. "BAC" is short for bacteriostatic, which just means it holds germs back.

BAC water is used to mix dried peptide powder into a liquid you can measure. The preservative in it keeps the liquid safe to use for weeks, so you can draw from the same bottle many times. Plain sterile water has no preservative, so it is one-time use only.

BAC water is sterile water with 0.9% benzyl alcohol (a germ-fighting preservative) added. Its pH is close to neutral (about 4.5 to 7, where 7 is neutral). In plain terms, it is close to the acidity of plain water. The benzyl alcohol is the only real difference between BAC water and plain sterile water.

Add enough BAC water so your dose lands on an easy-to-read number on your syringe. For a 5 mg peptide vial, 2 mL of BAC water is a common place to start. That makes a 250 mcg dose come out to about 10 units. Our BAC water calculator gives the exact amount for your vial strength and dose.

For most peptides, a 1 mL (U-100) insulin syringe works well. If your dose is always under 30 units, a 0.3 mL syringe is easier to read. It has half-unit marks. A 0.5 mL syringe is a good middle choice. Our syringe unit converter helps you convert between mL and syringe units.

Put BAC water in the fridge after you first open it. An opened multi-dose bottle is commonly dated and discarded within about 28 days, which is the standard multi-dose vial guidance. An unopened bottle is fine at room temperature until the printed expiration date. Mixed peptides also go in the fridge. How long a mixed peptide lasts depends on the compound, so follow the instructions that came with your product rather than a general figure. Our plan builder tracks the shelf life and expiration date for your peptide automatically.

In the US, BAC water is prescription-only when it is labeled for human use. The BAC water sold here is for research and educational use only. It is not sold over the counter for human use. We do not give medical advice.

Used the right way, BAC water is safe and widely used. A few simple steps matter. Wipe the top of the bottle before each draw. Keep it in the fridge after you open it. If the liquid turns cloudy or has floating bits, throw it out. Benzyl alcohol allergies are rare but possible. If you have known allergies, check the ingredients first. This is for research and educational use only, and it is not medical advice.

No. BACwater.ai gives you a BAC water calculator, mixing guides, and plain-language references. It sells nothing and recommends no vendor. We do not diagnose, prescribe, or give medical advice. Talk to a licensed healthcare professional for any medical questions.

More from our team

Do I need a prescription for BAC water? In the US, BAC water is prescription-only when marketed for human use. We provide research-use products intended for laboratory research and educational purposes, not for personal administration.

Is BACwater.ai a medical service? No. We provide a calculator, reconstitution guide, and supplies. We do not diagnose, prescribe, or provide medical advice.

Can I save my plans? Yes. Create a free account and every plan you build is stored with a permanent link.

Do you ship internationally? Currently US only. International shipping is on the roadmap.

How much BAC water should I add to reconstitute my peptide? The amount depends on your vial strength and desired dose. A common approach is to add enough BAC water so that your dose equals a clean, round number on your insulin syringe (e.g., 10 units). For a 5 mg peptide vial with a 250 mcg dose, adding 2 mL of BAC water makes each dose exactly 10 units. Use our BAC water calculator for an exact recommendation.

Can you reuse a BAC water vial? Yes. BAC water contains 0.9% benzyl alcohol preservative, which suppresses bacterial growth. A single 30 mL vial can be used for multiple reconstitutions over approximately 28 days when stored refrigerated. Always swab the stopper with an alcohol pad before each use and discard the vial if you notice cloudiness or particles.

What temperature should reconstituted peptides be stored at? Refrigerate reconstituted peptides at 36 to 46 °F (2 to 8 °C). Do not freeze. Do not leave at room temperature. Most reconstituted peptides are stable for approximately 28 to 30 days refrigerated. Store vials upright and protect them from light.

Which insulin syringe size is best for peptides? For most peptide doses, a 1 mL (100 unit) insulin syringe is the best default. If your dose is consistently under 30 units, switch to a 0.3 mL syringe for more precise markings. A 0.5 mL syringe is a good middle ground for doses between 10 and 50 units.

Why did my reconstituted peptide turn cloudy? A properly reconstituted peptide should be completely clear. Cloudiness can indicate contamination, degradation, or incomplete dissolution. If the powder hasn't fully dissolved, swirl the vial gently (never shake) and wait a few minutes. If cloudiness persists after dissolution, discard the vial and start fresh. Do not use a cloudy solution.

Can you be allergic to BAC water? Some individuals are sensitive to benzyl alcohol, the preservative in BAC water. Benzyl alcohol sensitivity is documented in the research literature. For any known benzyl alcohol allergy, consult a healthcare professional. In cases of benzyl alcohol sensitivity, sterile water for injection (single-use only) is often noted as a preservative-free alternative.

Can I combine two peptides in the same vial? Some research protocols combine compatible peptides (e.g., CJC-1295 and Ipamorelin) in a single vial for convenience. However, not all peptides are compatible when mixed. If your protocol calls for mixing, verify compatibility with the peptide manufacturer's documentation. When in doubt, reconstitute each peptide in its own vial.

How do I get rid of air bubbles in my syringe? After drawing your dose, hold the syringe needle-up and flick the barrel gently to move bubbles to the top. Then push the plunger slowly until the bubbles are expelled and a tiny drop appears at the needle tip. Pull back to your exact dose mark if needed. Small air bubbles are not dangerous but can affect dose accuracy.

Can I travel with reconstituted peptides? Reconstituted peptides must remain refrigerated. For short trips (a few hours), an insulated bag with ice packs can maintain temperature. For longer travel, consider transporting unreconstituted (lyophilized) peptides, which are stable at room temperature, and reconstituting at your destination. Always check local regulations regarding transport of research materials.

How long are reconstituted peptides good for? Most reconstituted peptides remain stable for approximately 28 to 30 days when stored refrigerated at 36 to 46 °F (2 to 8 °C). Some peptides like semaglutide may last longer (up to 56 days), while others like TB-500 may degrade faster (14 to 21 days). Our plan builder tracks expiration dates automatically based on each peptide's typical shelf life.

Still not sure?

The Plan Builder walks you through everything step by step. Just pick your peptide, vial, and dose, and we handle the rest. No math required.

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