How Are Peptides Made?

Peptides are made by joining amino acids together using a special bond called a peptide bond. This bond is formed when the amino group (–NH₂) of one amino acid combines with the carboxyl group (–COOH) of another amino acid, releasing a molecule of water.

Each amino acid has a central carbon atom, surrounded by:

• A hydrogen atom (H)
• An amino group (–NH₂)
• A carboxyl group (–COOH)
• A unique side chain group (called the R group) that gives each amino acid its own characteristics.

Sometimes, these R groups can interfere with the process of joining the amino acids, so they need to be temporarily protected with special chemical groups until the peptide chain is complete.

How are peptides made in a lab?

In laboratories, peptides are typically made using a method called solid-phase peptide synthesis. Here’s how it works:

1. Starting the Process: The first amino acid is attached to a solid support (a resin) to keep it in place, and its amino group is protected.
2. Adding More Amino Acids: The protective group is removed, allowing the next amino acid to be added. This amino acid forms a peptide bond with the first one.
3. Repeating the Process: The process is repeated, adding one amino acid at a time until the entire peptide chain is created.

Once all the amino acids are in place, the peptide is carefully removed from the solid support. A special acid is used to break the bond between the peptide and the solid support, and it also removes any remaining protective groups on the amino acids.

This step-by-step process allows scientists to create peptides with specific sequences of amino acids for use in research, medicine, or other applications.

I wanted to provide some information regarding the presence of mannitol in the peptide products we offer at UK Peptides.

All our peptides contain trace amounts of mannitol, which is essential in the formulation and preservation of the products. Mannitol is a sugar alcohol that offers several benefits in peptide formulations, including

• Stability: Mannitol helps maintain the stability of peptides by preventing aggregation and preserving their structural integrity. This is particularly important during lyophilisation (freeze-drying) and storage to minimise degradation and maintain the peptide's bioactivity.
• Solubility: Mannitol enhances the solubility of peptides, making it easier to dissolve and reconstitute them in a suitable solvent, such as water or saline, before administration.
• Protection from Moisture: Mannitol is hygroscopic, which attracts and holds water molecules from the surrounding environment. This property helps protect the peptide from excess moisture, which can cause degradation or loss of potency.
• Improved Flow Properties: Mannitol has good flow properties, which makes it easier to handle and process during manufacturing. It also improves the flowability of peptide powders, which can be crucial for accurate dosing and dispensing.

Additionally, without the presence of mannitol or other excipients, peptide vials may appear to be empty. The small amount of mannitol used ensures that you can visually confirm the presence of the peptide product in the vial.

We hope this information helps you understand the importance of mannitol in our peptide products. If you have any further questions or concerns, please don't hesitate to reach out. We're here to help.

How should I handle and store my peptides?

Peptides attract moisture from the air, so it's important to let the peptide warm up to room temperature before opening the container. The best way to do this is to warm it in a desiccator or dry box to prevent water condensation from forming on the peptide.

When handling peptides, follow these steps:

1. Weigh the product quickly in a clean environment, taking only the amount needed to minimise contamination.
2. Reseal the container tightly after use.
3. Store any unused peptide at -20°C or lower in a sealed container with a desiccant (a substance that absorbs moisture).

Storing peptides under these conditions will reduce and prevent bacterial degradation, secondary structure formation, and oxidation for up to several years. However, peptides containing certain amino acids like cysteine, methionine, tryptophan, asparagine, glutamine, and N-terminal glutamic acid will have a shorter shelf life.

When dissolving peptides, use the recommended solvents provided by UK Peptides if your experimental conditions allow it. Sonication (using sound waves) can help dissolve the peptide. In general:

• Sterilised water is the preferred solvent.
• Acidic peptides will dissolve in a basic buffer.
• Basic peptides will dissolve in an acidic buffer.

Peptides containing cysteine, methionine, and tryptophan require oxygen-free solvents as they are prone to oxidation.

Important: Peptides in solution are much less stable than in lyophilized (freeze-dried) form and will remain viable for a much shorter period. It's not recommended to store peptides in solution, but if unavoidable, keep them at -20°C using sterile buffers at pH 5-6 to prolong shelf life. The best way to avoid this issue is to have UK Peptides aliquot (divided into smaller portions) the peptide for you.

We accept bank transfers, bitcoin, and card payments (in limited countries).

At the checkout, you will be asked which payment method you would like to use.

Bank Transfer

It is simple to make a bank transfer with your online banking or mobile banking app, or you can also make the transfer in a branch.

Please ensure you confirm your order.

Please note: If you pay into our account using another person's bank account, such as your partner's or friend's account, please get in touch with us and tell us the name of the bank account and your order ID number to avoid any delays in postage times.

Bitcoin

Once you confirm your order, a pop-up screen with a QR code should appear. Use this to make the payment or use the wallet address. This process will usually take an hour before the order is confirmed; in some occasions, this can be longer. If your screen has timed out, don't worry; our system will complete the order once the payment has been successful.

Card Payment By Link

UK customers: Once you have confirmed your order, we will manually create your unique link, which we will email to you. If you have made the order outside working hours, we will process your link on the next working day.

International customers: You can process the order once you have confirmed it.

Shipping Options

For our UK Customers

We provide two convenient shipping options:

• Royal Mail 24: Priced at £4.50, this option offers reliable and swift delivery across the UK.
• DPD UK: For a slightly higher fee of £5.20, you can opt for DPD's trusted delivery services within the UK.

For our International Customers

We select the most efficient shipping option based on your location, using either Royal Mail or DPD International. To ensure a smooth delivery process, we encourage you to follow your shipment closely using the provided tracking information. Additionally, please consider arranging a safe place for your parcel or request a delivery rearrangement if needed for your convenience.

Tracking Your Parcel

For customers who have selected DPD, you can download the DPD app to receive real-time updates on your delivery. For Royal Mail shipments, please visit their tracking website and enter your tracking number for the latest information.

Our Parcel Follow-up Policy

We understand the importance of timely deliveries. However, we request that you allow up to seven days for your parcel to arrive before contacting us for a follow-up. This timeframe helps accommodate any minor delays that are common in shipping processes.

International Deliveries and Customs

For our international customers, please be aware that if your parcel is held in customs, there may be delays outside our control. In such cases, patience is appreciated. If customs request additional documents, we are here to assist you. However, the resolution time depends on the response from customs authorities.

Shipping Process

All peptides we ship are in their lyophilised (frozen, dried) state. This form ensures their stability and integrity during transit. We take great care in packaging to safeguard the peptides from potential environmental factors.

Protection from Sunlight

The most crucial factor during transportation is to keep the peptides away from direct sunlight. Our packaging is specifically designed to provide this protection, ensuring the peptides reach you in the best possible condition.

Post-Delivery Handling and Storage

Upon receiving your peptides, it's important to continue proper handling. Once you reconstitute the peptides, we recommend storing them in the refrigerator. This practice is essential to maintain their optimal quality and effectiveness.

Need Further Assistance?

If you have any further questions or concerns about our peptides, their shipment, or how to handle them post-delivery, please don't hesitate to contact us. Our team is here to provide you with all the necessary support and guidance.

Thank you for your recent order and for updating your payment.

Please note that we do not individually confirm payments, which would significantly extend our processing time. Our main goal is to ensure all orders are efficiently processed by the end of each day.

Rest assured, our dispatch team will immediately begin processing your order once your payment is registered in our account. You will receive an email confirmation and the tracking information later this evening.

Your understanding and continued support are greatly appreciated.

I regret to inform you that we currently do not offer blends of peptides, such as ipamorelin and CJC MOD GRF. Blending peptides is often a marketing strategy; in many cases, the ratios may not be appropriate for most research applications.

Additionally, the exact microgram usage for each component in the blend can't be accurately determined, which may impact your results.

We strongly recommend purchasing peptides separately. This approach allows you to administer the precise microgram dosage of each peptide, ensuring your research is accurate and reliable. For instance, if you want to use more than one peptide at a time, you could add 100mcg of Peptide A and 100mcg of Peptide B into the same syringe. This guarantees that you know exactly what and how much you are using.

As for the cost, the idea that combining two peptides into a single vial would be cheaper is a common misconception.

Hence, our advice would be to acquire the peptides separately to maintain the integrity and accuracy of your research.

Thank you for understanding.

Once a parcel leaves the UK and enters another country’s postal system, it may be held by customs for checks. This is completely outside of our control, and we cannot contact or influence customs in your country.

We understand this can be frustrating, but we’re unable to speed up the process or provide updates beyond the tracking link. Customs clearance times vary depending on each country’s procedures.

If your parcel hasn’t moved for a while, this does not mean it’s lost — it is most likely awaiting processing by your country’s customs office.

We can only raise an investigation after 28 working days from the dispatch date, as this is the timeframe required by Royal Mail and international couriers.

Yes, we are committed to the highest product quality and transparency standards. A Certificate of Analysis (CoA) is available for all our products. To access the CoA, visit the respective product page on our website and select the 'Certificate of Analysis' option. This will allow you to download the document in PDF format. Please note all our CoA documents are provided for informational purposes and must not be modified or edited in any way.

Net peptide content differs from total (or gross) peptide content. The lyophilised peptide powder you receive contains not just the peptide, but also other substances like water, solvents, counterions, and salts. The total peptide content refers to the weight of this entire mixture (Gross Weight). In contrast, the net peptide content is the actual weight of the peptide itself within the sample.

Understanding Net Peptide Content

Typically, the net peptide content is around 60-90% of the total peptide weight. This percentage is usually determined through methods such as elemental analysis, amino acid analysis (AAA), or UV spectrophotometry.

Peptides Purified by Reverse-Phase HPLC

For peptides purified using reverse-phase High-Performance Liquid Chromatography (RP-HPLC), the buffer (commonly TFA/H₂O) can contribute salts to any free amine groups in the peptide. These salts can be exchanged through ion-exchange processes. Most peptide APIs are produced as acetate salts.

Net Peptide Content vs. Purity

It's important to note that net peptide content differs from purity. Purity refers to the percentage of the target peptide sequence in the sample, while net peptide content indicates the actual amount of peptide present. When calculating concentrations, it is crucial to consider the net peptide content.

What is the Difference Between Peptide Purity and Peptide Yield?

Peptide purity refers to how "clean" the peptide sample is. We check this using tools like reverse-phase high-performance liquid chromatography (RP-HPLC) and mass spectrometry (MS). These methods give us a percentage that shows how much of the sample is made up of the actual peptide. It doesn’t include things like water or salts that might also be in the sample.

On the other hand, Peptide yield is all about how much peptide is actually there. We figure this out with something called Amino Acid Analysis (AAA), which measures the exact amount of peptide in the sample. This method tells us how many moles of peptide we have. The difference between the weighed mass of the sample and the result after AAA is usually because of water and salts.

What Are Lipopolysaccharides (LCPS) and How Do We Keep Them Out of Our Products?

Lipopolysaccharides (LCPS), also known as endotoxins, are large molecules found in the outer membrane of certain bacteria like E. coli. These substances can cause strong immune reactions, so having them in peptide products is a big problem, especially for research or therapeutic uses.

At UK Peptides, we make sure our products are free from LCPS by using synthetic peptides. Some companies use bacteria, like E. coli, to create peptides, but this method increases the risk of contamination with LCPS. Our synthetic approach avoids this entirely.

We use advanced chemical processes to build peptides in a highly controlled environment. This means we can guarantee high purity, consistency, and, most importantly, no bacterial contaminants like LCPS. We also avoid other potential impurities that might come from biological production systems.

In short:

By choosing synthetic peptides, we ensure our products are clean, safe, and reliable, making them perfect for your research and therapeutic needs.

What About Third-Party Lab Results?

We understand that many customers ask about third-party HPLC reports, but it's important to know the reality behind these claims in the peptide industry.

1. No Credible Third-Party Lab Exists for Routine Peptide Testing

At this time, there is no widely recognised, independent third-party lab that routinely verifies research peptides for commercial use. The labs often promoted as “third-party” by new or underground sellers are usually not regulated, and their reports cannot always be trusted as credible. In many cases, these labs are not truly independent and may operate without proper transparency or standards.

2. Why We Don’t Offer Public Third-Party Reports

While we work with a trusted laboratory partner in Germany, they are not a public-facing third-party verifier. We’ve signed a Non-Disclosure Agreement (NDA) to respect their privacy and protect their operations. This is a working relationship based on mutual trust and quality control, not a marketing tool.

3. In-House Quality Assurance and COAs

All of our batches go through strict in-house testing, and we supply a Certificate of Analysis (COA) with every peptide. This COA verifies key data like purity and composition, backed by over 13 years of experience with our manufacturing partners. We produce small, controlled batches to ensure consistent results and never use resellers or third-party stock.

4. Our Recommendation: Test for Yourself

The most reliable way to confirm purity is through your own in-house testing. This is what we recommend to all research clients. Start with a small order, run your own verification if needed, and scale your research from there. It’s the only true way to ensure confidence in the peptide — and we’re confident you’ll be satisfied.

5. Beware of Misleading Marketing

Many new sellers in the peptide space use buzzwords like “fully traceable” or “independent third-party verified” to sound credible but these claims are rarely backed by true transparency or consistent quality. We prefer to focus on real testing, trusted manufacturing, and honest communication.

Summary

We don’t rely on flashy third-party marketing claims instead, we focus on batch consistency, in-house testing, and long-standing supplier relationships. We stand by the quality of our products and always encourage customers to conduct their own verification. That’s the most reliable form of trust in this industry.