Frequently asked questions

Find answers to common questions about our products and services

  • Zenterex operates a strict no-return policy except in circumstances where an error has occurred on our part.

    For bulk orders or orders containing high quantities of the same item, should an error occur that is demonstrably due to a mistake made by Zenterex (such as incorrect items, damages, or defects), we are more than happy to sort this out and handle it by offering a replacement or refund.

    However, for single units or small orders, if the reason for the return is not our fault, or if the item is perfectly fine and the customer simply wishes to return it for no reason, we do not accept returns.

    Refunds will only be issued where the goods supplied are demonstrably damaged, defective, or incorrect due to a mistake made by Zenterex. In such confirmed cases, the customer must notify us in writing at support@zenterex.com within 7 days of receipt of the goods, providing adequate photographic or documentary evidence to allow us to investigate the matter.

    Where Zenterex confirms that the fault lies with us, we will, at our discretion, offer either a replacement of the affected product or a refund of the purchase price. Goods must remain unused and in their original condition and packaging unless the defect itself prevents this.

    No refunds will be granted in any circumstances where the error originates from the customer. This includes, but is not limited to, ordering the wrong product, misunderstanding the nature or intended use of the product, providing incorrect delivery information, failure to collect or accept the delivery, or any situation where the product is refused, delayed, or seized due to customs intervention or regulatory issues beyond the control of Zenterex. In all such cases, responsibility rests solely with the customer.

    Under no circumstances will Zenterex issue refunds for reasons unrelated to a proven company error. All sales are otherwise considered final upon dispatch.

  • We understand that receiving your order promptly is important. At Zenterex, we prioritize efficiency and swift handling to ensure the fastest possible dispatch.

    Processing and Shipping

    • Processing Time: We will work quickly to process and prepare your order for shipment as soon as possible following payment confirmation.
    • Shipping Notification: Once your order has officially shipped, you will receive a comprehensive email notification containing all necessary tracking information and further details regarding your shipment.

    Delivery Times

    Delivery times are variable and depend on your geographical location and the specific shipping method selected at checkout.

    • UK Orders: Typically arrive within 1-3 business days after dispatch.
    • International Orders: Delivery times can vary significantly based on the destination country, local postal services, and customs clearance procedures. You will be able to see the estimated delivery time for your region during the checkout process.

    We encourage customers to regularly check the provided tracking link for the most current updates on their order's delivery status.

  • Yes, we ship to most countries worldwide. International shipping times and costs vary by destination.

  • Once your order ships, you'll receive a tracking number via email. You can use this to track your package on our website or the carrier's site.

  • We accept all major credit cards, PayPal, Apple Pay, and Google Pay for your convenience.

  • Peptides are created by linking amino acids with peptide bonds. This bond forms when one amino acid’s amino group connects with another’s carboxyl group, releasing water.

    In the lab, peptides are usually made through solid-phase peptide synthesis:

    1. Start: The first amino acid attaches to a solid support with a protected amino group.
    2. Add Amino Acids: The protecting group is removed, and the next amino acid is added to form a bond.
    3. Repeat: This process continues until the desired peptide is complete.
    4. Finish: The final peptide is detached from the solid support and any remaining protecting groups are removed.

    This method allows scientists to create peptides with specific amino acid sequences for research and development.

  • Yes, all of our peptides contain trace amounts of mannitol.

    Mannitol is a sugar alcohol commonly used in the pharmaceutical and research industries. It is included in our formulations to serve as an excipient—a non-active stabilizing agent—that ensures the quality, handling, and longevity of the lyophilized (freeze-dried) peptide powder.

    Benefits of Mannitol in Peptide Formulations

    Mannitol is included because it provides several functional benefits:

    • Stability: It acts as a bulking agent, preventing the delicate peptide molecules from aggregating and helping to maintain their proper structure during the freeze-drying process and storage.
    • Solubility: Mannitol enhances the peptide's ability to dissolve (solubility) quickly and completely when reconstituted with water or saline.
    • Moisture Protection: It absorbs residual moisture, helping to shield the peptides from water-induced degradation.
    • Handling: It improves the flow properties of the peptide powder, making it easier to handle and ensuring that the small quantity of the peptide product is visible in the vial.

  • Our peptides are supplied in lyophilised powder form inside sealed sterile vials. Before they can be used for research and analytical purposes, they must be reconstituted  bacteriostatic water (BAC water).

    What you will need

    -Peptide vial (lyophilised powder)

    -Bacteriostatic water

    -Alcohol swabs

    -Sterile syringe

    Recommended needle gauge: 29–31G for drawing small volumes; 18–21G for drawing BAC water depending on your preference

    (Always use a fresh, sterile needle for each step.)


    How to reconstitute a peptide (laboratory instructions)

    1. Clean the vial tops

    Wipe both the BAC water vial and the peptide vial’s rubber stoppers with an alcohol swab.

    2. Draw up the BAC water

    Using a sterile syringe, withdraw the desired amount of bacteriostatic water.

    Most researchers add between 1–5 mL depending on preferred concentration.

    3. Inject the BAC water into the peptide vial

    Insert the needle at a slight angle and allow the water to flow gently down the inside of the vial.

    Avoid spraying the water directly onto the powder to prevent foaming.

    4. Let the peptide dissolve

    Do not shake the vial. Gently swirl or roll it between your fingers until fully dissolved.

    The peptide should reconstitute into a clear solution.

    5. Store appropriately

    Once reconstituted, peptides should be stored at 2-8 Degrees Celsius typically in the fridge

  • Yes, we provide a Certificate of Analysis (CoA) for all products.

    Our commitment to unbeatable quality and transparency is backed by rigorous testing. All of our peptides have corresponding Janoshik Lab Reports, confirming they are proven and tested to meet our high purity standards.

    To obtain the CoA for a specific product:

    1. Visit the corresponding product page on our website.
    2. Select the ‘Certificate of Analysis’ option.
    3. Download the PDF document.

    Please note that all CoA documents are provided for informational purposes only and must not be modified or edited in any way.

  • Our products are guaranteed to be free from Lipopolysaccharides (LCPS), also known as endotoxins.

    LCPS are undesirable bacterial contaminants (from E. coli and similar bacteria) that can trigger strong immune responses, compromising research results.

    Our Solution: Synthetic Peptides

    We eliminate this risk by exclusively using advanced chemical synthesis to create our peptides:

    • No Bacterial Systems: Unlike methods that use bacterial expression systems, our synthetic approach removes the source of LCPS contamination entirely.
    • High Purity: We precisely construct peptides in a controlled environment, guaranteeing the absence of LCPS and other bacterial contaminants.

    This commitment provides you with safer and more reliable peptide solutions for your research needs.