Research Peptide FAQ: 30+ Questions Answered (Purity, Storage, Dosing)

Q: What is the difference between HPLC and Mass Spec on a COA?

HPLC measures the percentage purity. Mass Spec confirms molecular identity. A complete COA requires both.

Q: Do I need to refrigerate peptides during shipping?

No. Lyophilized peptides are stable at room temperature for 30-60 days and survive standard shipping.

Q: How do I reconstitute a research peptide vial?

Wipe the rubber stopper with alcohol, draw bacteriostatic water into a sterile syringe, inject down the inside wall, and swirl gently. Do not shake.

Q: How much bacteriostatic water do I add to a 10mg vial?

Most researchers use 2 mL or 3 mL. 2 mL gives 5 mg/mL concentration.

Q: How long do reconstituted peptides last?

Approximately 28 days at 2-8 degrees C in the refrigerator.

Q: Can I freeze a reconstituted vial?

No. Freezing forms ice crystals that reduce peptide activity by 20-50% per freeze-thaw cycle.

Updated May 2026 · By the Onyx Biolabs Research Team · For laboratory research use only

This page collects the most frequently asked questions about research peptides — how they’re made, tested, shipped, stored, and reconstituted — with answers consolidated from our Kovera Labs analytical data and standard laboratory protocols. Use this as a single-page reference; jump to a category below or search the page (Ctrl/Cmd + F).

Purity and lab testing

What purity do Onyx Biolabs peptides meet?

Every batch is independently tested by Kovera Labs and meets a minimum 99% HPLC purity standard. Q1 2026 average across 16 batches was 99.4%, with the highest batches reaching 99.9%.

Who tests Onyx Biolabs peptides?

Kovera Labs, an independent third-party analytical chemistry laboratory. Every batch ships with a COA (Certificate of Analysis) showing both HPLC purity and Mass Spec identity confirmation.

What is the difference between HPLC and Mass Spec on a COA?

HPLC (high-performance liquid chromatography) measures the percentage purity of the peptide. Mass Spec measures the molecular weight, confirming the molecule is what the label says. A complete COA requires both. For a full guide, see How to Read a Certificate of Analysis.

Where can I see the COA for my batch?

At https://onyxbiolabs.com/lab-results/. Every batch number on your vial label matches a published COA on that page.

How often are batches retested?

Every new production batch is tested before it enters inventory. Existing lots are not retested unless storage conditions change. The COA on file represents the batch quality at the time of release.

What molecular weight should I see for the most common peptides?

BPC-157: ~1,419 Da. TB-500: ~889 Da. Retatrutide: ~4,731 Da. Tirzepatide: ~4,814 Da. Semaglutide: ~4,113 Da. KPV: ~342 Da. Each Mass Spec report should match the theoretical mass within +/- 1 Da.

What if my COA shows a purity below 99%?

Contact support immediately. Onyx Biolabs guarantees minimum 99% HPLC purity on all batches. A below-spec batch is an error and we will replace it or refund.

Shipping, customs, and delivery

How fast do orders ship?

Orders placed before 2 PM Eastern ship same-business-day from our Charlotte, NC facility. After 2 PM orders ship next business day.

How is shipping packaged?

Lyophilized peptides are shipped in vacuum-sealed glass vials inside padded mailers. No ice packs are required because lyophilized peptides are stable at room temperature for weeks.

Do I need to refrigerate peptides during shipping?

No. Lyophilized (freeze-dried) peptides are stable at room temperature for 30–60 days. Standard 3–7 day shipping does not affect purity. See the stability guide.

What if my vial arrived hot from sitting in the mail?

Lyophilized peptides tolerate brief exposure (up to 7 days) at up to 37°C without significant degradation. As long as the powder still looks white and free-flowing, the vial is usable.

Do you ship internationally?

Onyx Biolabs ships primarily within the United States. International shipping is offered to select countries on a case-by-case basis; contact support before ordering.

What about customs?

For US-bound orders, no customs issues apply. International orders may face customs review depending on the destination country’s regulations on research chemicals. Contact support if you have questions about a specific country.

Is shipping free?

Free standard ground shipping on all orders over $200 within the US.

Reconstitution and dosing

How do I reconstitute a research peptide vial?

Wipe the rubber stopper with an alcohol prep pad, draw bacteriostatic water into a sterile insulin syringe, slowly inject down the inside wall of the peptide vial, and swirl gently until dissolved. Do not shake. See the full protocol at How to Reconstitute Research Peptides.

How much bacteriostatic water do I add to a 10mg vial?

Most researchers use 2 mL or 3 mL. 2 mL gives a concentration of 5 mg/mL (1 syringe unit = 50 mcg). 3 mL gives 3.33 mg/mL. Use the peptide calculator for exact volumes.

What is bacteriostatic water and why do I need it?

Bacteriostatic water is sterile water containing 0.9% benzyl alcohol, an antimicrobial preservative. The benzyl alcohol inhibits microbial growth for 28 days, giving multi-dose research vials a usable shelf life. Plain sterile water has no preservative — reconstituted vials only last 24–48 hours.

Can I shake the vial to dissolve the powder faster?

No. Shaking creates foam and can denature the peptide, reducing activity. Always swirl gently or roll the vial between your palms.

Where do I buy bacteriostatic water?

Onyx Biolabs sells bacteriostatic water in 10 mL vials. Sterile, USP-grade, made for research reconstitution.

What syringe should I use?

A 1 mL (100-unit) insulin syringe with a 29G or 31G needle is standard for both reconstitution and dose measurement. Unit markings make dosing math straightforward.

Storage and stability

How should I store lyophilized peptides?

Short-term (under 60 days): room temperature in a dark cabinet. Long-term: freezer at -20°C in a sealed bag with a desiccant packet. Avoid humidity and direct sunlight.

How long do reconstituted peptides last?

Approximately 28 days at 2–8°C (refrigerator main compartment). The bacteriostatic water’s benzyl alcohol inhibits microbial growth for that period.

Can I freeze a reconstituted vial?

No. Freezing forms ice crystals that physically disrupt the peptide structure, reducing activity by 20–50% per freeze-thaw cycle. Refrigerate at 2–8°C only.

How do I tell if a peptide has degraded?

Lyophilized powder should be white and free-flowing. Color change (yellow/brown), clumping, or moisture indicates degradation. Reconstituted solution should be clear and colorless. Cloudiness, particulate, or color tint means do not use.

How long are unopened lyophilized vials stable?

At -20°C with desiccant: 24+ months. At room temperature: 30–60 days. Some research labs report 36+ months at -80°C with no measurable degradation.

Legal status and research compliance

Are these peptides legal in the United States?

All Onyx Biolabs peptides are sold legally as research chemicals for in-vitro and laboratory research use only. None is approved by the FDA for human consumption and none is sold for that purpose.

Is Onyx Biolabs a compounding pharmacy?

No. Onyx Biolabs is a chemical supplier. Onyx Biolabs is not a compounding pharmacy or chemical compounding facility as defined under 503A or 503B of the Federal Food, Drug, and Cosmetic Act.

Do I need a research license to order?

Research-use-only compounds are generally available to researchers, laboratories, academic institutions, and qualified individuals for in-vitro and analytical research. You are responsible for compliance with all applicable laws in your jurisdiction.

What does “research-use-only” mean?

It means the compound is sold strictly for laboratory and in-vitro experimental research, not for human or animal consumption, diagnostic use, or therapeutic application. Statements have not been evaluated by the FDA.

Ordering, payment, and refunds

What payment methods do you accept?

Credit/debit card, ACH and bank transfer, Zelle, CashApp, and major cryptocurrencies.

How do I track my order?

You will receive a tracking link via email when your order ships. You can also check status anytime at /track-your-order/.

What is your refund policy?

See our return and refund policy for full terms. Damaged or below-spec batches are replaced or refunded.

How do I contact customer support?

Email support@onyxbiolabs.com or call +1 (704) 665-5551. We typically respond within one business day.

Do you offer a first-order discount?

Yes. Use code FIRSTORDER at checkout for 10% off your first order.

Related research protocols and guides

Disclaimer

For research, laboratory, or analytical use only. All compounds discussed are not approved for human or animal consumption. The statements on this page have not been evaluated by the FDA. Onyx Biolabs is a chemical supplier and is not a compounding pharmacy or 503A/503B facility.