MedKoo Frequently Asked Questions and Answers


Section 1: Product availability and usage

Q: What do you mean by "Ready to ship," "Same day," "2 weeks," and "2-3 months" in the price table?

When a product is labeled as "Ready to ship" or "Same day," it signifies that the product is currently located in our USA warehouse and can be dispatched on the same day that the purchase order (PO) is received. Please note that the cutoff time for same day shipping is 4:00pm EST.

On the other hand, when a product is marked as "2 weeks," it means that the item may be available through our partners. However, we require approximately 2 to 3 weeks to transfer the product to our USA warehouse before it can be shipped.

Lastly, if a product is designated as "2-3 months," it indicates that the manufacturing process for that specific item will take approximately 2 to 3 months to complete before it can be made available for shipment.


Q: Do you sell products for human/patient use?

No, all of our products are solely intended for research purposes. Under no circumstances should our products be utilized for any other purposes or in any manner that violates any laws or regulations. It is important to note that our products are explicitly not intended for use as drugs, food additives, cosmetics, household chemicals, or any other inappropriate applications. Our products should exclusively be employed by trained scientists operating within controlled conditions, who possess a comprehensive understanding of the potential hazards involved.


Section 2: Product shipping and storage condition, shelf life

Q: How long will it take to deliver my order to my company?

We strive to deliver your order as quickly as possible. Typically, products are delivered to addresses within the USA the next business day. For Canadian addresses, delivery times range from next day (major cities) to 2-5 days (other addresses). International delivery usually takes between 3 and 10 days, depending on the efficiency of customs clearance.


Q: Can you guarantee the delivery time?

Unfortunately, we cannot guarantee the exact delivery time of your order. We primarily utilize FedEx, and, less often, DHL. Generally, both FedEx and DHL perform well in delivering packages on time. However, various factors beyond our control can cause potential transportation delays.


Q: What is the cut-off time for same day shipping?

The cut-off time for same day shipping is 4:00 pm EST (Monday through Friday). For products marked as "ready to ship" or "same day" in the price table, we can arrange for the order to be shipped out on the same day from our location in Durham, North Carolina, USA, once the order is received.


Q: Can you lower the customs value for my order?

No, we are unable to comply with that request as it is illegal. If you qualify for customs duty and tax waivers, you should obtain a Tax-free certificate from your State Tax Administration Office. With this certificate, your customs office will not charge you tax or duty. However, please note that you may still be required to pay handling or inspection fees to the customs authorities in your country.


Q: Can you ship my order directly from China to my company?

No, we cannot ship your order directly from China to your company. We do not have an operations facility in China. We have partners in China, but they do not handle sales, technical support, or customer service. All orders will be shipped from our USA headquarters located in Durham, North Carolina.


Q: How much will the shipping cost be?

For a list of shipping and handling fees, please see the web page for "how to order".


Q: May I use my own FedEx COLLECT Account?

Yes. Please note that a small handling fee ($15.00) will be added to your invoice.


Q:What is the difference between Standard Overnight Shipping and Priority One?

Packages that are shipped Standard Overnight are scheduled to be delivered by 4:30 PM the next business day. Priority One guarantees shipments before 10:30 AM the next business day.


Q: What type of packaging do you use?

Packaging is chosen to meet the specific needs of the product being packaged. Most of our chemical reagents are packaged in borosilicate vials with amber color and Teflon septa screw caps. Smaller size (less than 10mg) chemicals are packed into 1~2 mL plastic vials with O-ring screw caps. Specialty packaging may be used for products with specific needs for sealing, such as flame-sealed glass ampules for some sensitive chemicals. If you have specific packaging requirements, please contact our customer service staff for assistance.


Q: There is a clear liquid visible inside the plastic bag my product was shipped in. Does this mean the vial leaked? Is it safe to handle this material?

Materials stored at -20°C or -80°C may have water vapor condense within the plastic bag as the materials are packed for shipment. This does not impact the product inside the vial. If the vial inside the bag is not broken or cracked the liquid is generally not a concern. Proper PPE should always be worn when handling hazardous chemicals.


Q: When I received my package, one of the products I purchased was broken. What should I do?

MedKoo takes great care in packaging shipments to prevent damage to inner and outer packaging. While extremely rare, breakage can occur during transit. All products should be inspected upon receipt. If you happen to receive a broken vial, please contact our customer service staff within 30 days of the date of shipment for assistance. 


Q: I have noticed different color caps on MedKoo products. Does the color of the cap have a meaning?

The colors of the caps on the vials do not have specific meanings and may vary depending upon packaging supply at the time of aliquoting.


Q: Does product stable at ambient temperature for more than 1 week due to unexpected longer custom clearance?

Most of our products are relative stable at room temperature for at least 2 months. Such products can be shipped under ambient temperature as non-hazardous chemical. These products are stable enough to undergo ordinary shipping conditions and time spent in Customs.


Q: What is the expiration date for the product that I ordered:

Most of our products, when stored in pure solid powder state, dry, dark and cold conditions, will be stable for at least 2 years after you receive the order. After 2 years, it may need to be tested again to confirm the quality.


Q: What are the storage conditions for solid powder?

Dry, dark and at 0 - 4°C for short term (weeks to months) or -20°C for long term (months to years).


Q: What are the storage conditions for my stock solution?

At -80°C, your stock solution may be stable up to ~3 months. At -20°C your stock solution may be stable up to ~2 weeks.



Section 3: Product quality

Q: What does QC data include?


Q: How can I get a CoA and QC data?

 (1) For products listed as “ready to ship" or "same day” in the price table, you can download the CoA and QC data under “QC and documents” tab.

(2) For products listed as “2 weeks” under availability in the price table, the CoA and QC data will be available about1-2 weeks after you have placed the order. Typically, “2 weeks” products are supplied by our partners, with only CoAs available and QC data usually unavailable. Whether QC data is available or not, the quality is 100% guaranteed.

(3) For products without listed prices, it means the product is not in stock, and may be available by custom synthesis. In this case, CoA and QC data will be only provided after the product has been successfully made and tested.


Q: Can you tell me what solvents were used when you made your product?

No, manufacturing details including solvents used will not disclosed to customers. We will put forth our best efforts to remove all possible solvent residues. Quality is 100% guaranteed.


Q: I want to re-test the product purity, can you share your HPLC analytical method?

No, we generally do not share the HPLC method for purity analysis since many of our HPLC analyses were performed by third-party service providers. The methods of HPLC analysis are the intellecutal property of the service providers; MedKoo does not own the HPLC methods, and therefore, we cannot share the HPLC methods. If there is a quality issue, MedKoo will try our best to help.


Q: Is your product 100% pure? If not, can you tell me the chemical structures of the impurities

It is our goal to make the products as pure as possible. However, it is impossible to make products 100% pure. Similar to most other reputable reagent vendors, we do not characterize the impurities. Most of our products have purity > 98% by HPLC. The potential impurities may be solvent residues, hydrate, trace amount of unreacted raw materials or unremovable side-products, which should not impact your in vitro or in vivo test.


Q: What are the limitations for NMR, HPLC and MS analysis for QC test?

(1) NMR analysis cannot detect impurities which have no protons such as inorganic salt sodium chloride

(2). Most HPLC analysis uses a UV-Vis detector, which cannot detect impurities that have no UV-Vis absorption.

(3) MS analysis cannot tell you the purity.

(4) By combination of NMR, HPLC and MS analysis, an accurate approximation of product quality in both structure correctness and purity can be obtained.


Q: Do you have DMFs on file?

No, not at this moment.


Q: Have your facilities been audited?

No, not at this moment.


Q: Are your facilities GMP Certified?

No, not at this moment.


Q: Are your facilities ISO Certified?

No, not at this moment.


Q: Are your facilities inspected by the US-FDA?

No, not at this moment.


Q: Do you sell DEA controlled substance?

No, not at this moment.



Section 4: Product technical questions.

Q: How do I report an information discrepancy for a MedKoo product?

Please send an email to, where our Technical Support scientists will review and give you feedback ASAP.


Q: I found different solubility data from different sources. Which one is right?

Customers may use our solubility as a reference for stock solution preparation. There can be variations in solubility for the same chemical from different vendors or different batches from the same vendor. The following factors can affect the solubility of the same chemical: solvent used for crystallization, residual solvent content, polymorphism, salt versus free form, degree of hydration, and solvent temperature. Still have questions? Please contact our Technical Support scientists.


Q: I want to deliver my compound to animals. What is the best solvent to use?

When choosing a delivery vehicle, consider the properties of the compound (polarity, solubility, stability), the route of administration, the final intended dose, animal mass, and possible confounding effects of the solvent. While water and saline are convenient for gavage and injection, they are not suitable for hydrophobic compounds. Ethanol and DMSO can be used to make stock solutions but should be present at less than 0.1% in most applications.* Even then, they may have unwanted effects in certain systems. Vehicles such as vegetable oil or polymer preparations of cyclodextrin (CD), carboxymethyl cellulose (CMC), or polyethylene glycol (PEG) can be effective vehicles for extremely hydrophobic compounds. With any vehicle, toxicity should be assessed with a vehicle control before testing the compound in large numbers of animals. Note: All animal experiments should be authorized by your Institutional Animal Care and Use Committee and/or veterinary staff. MedKoo's research grade chemicals are not supplied as sterile or tested for endotoxin (unless specifically stated). For further information contact our Technical Support scientists.

*Verheijen, M., Lienhard, M., Schrooders, Y., et al. DMSO induces drastic changes in human cellular processes and epigenetic landscape in vitro. Sci. Rep. 9(1), 4641 (2019).


Q: Is it possible to obtain a Safety Data Sheet (SDS) in languages other than English?

At this moment, our SDS documents are only available in English. Customers may download our English version to translate it into your language using Google Translate. The web page is Please note that some static parts of the SDS may still be in English. This is unavoidable.


Q: Does the weight of the salt contribute to the concentration?

MedKoo compounds offered as salts are typically supplied as solids. When preparing stock solutions based on molarity, weighing should be based on the formula weight, which includes the weight of the salt. For example, MedKoo offers Osimertinib free base (FW 499.61) and the Osimertinib mesylate (FW 595.72). Making a 1 molar solution of Osimertinib mesylate salt requires 595.72 g solid per liter. Making a 1 molar solution of Osimertinib free base will requires 499.61 g solid per liter.


Q: My compound is to be used for cell culture or in vivo studies, but the solubility information presented on the product insert does not allow for a low enough solvent concentration for such studies. What should I do?

Solubility can present challenges in many applications. Commercial preparations of polymers such as cyclodextrin (CD), carboxymethyl cellulose (CMC), polyethylene glycol (PEG), and similar polymers have been used to solubilize or suspend hydrophobic compounds. β-cyclodextrin (hydrate) and 2-hydroxypropyl-β-cyclodextrin, which have been used by researchers as approaches to similar solubility issues. Alternatively, liposomes as delivery vehicles may be an approach to consider for some compounds. For additional information, please contact our Technical Support scientists.


Q: I could not dissolve my compound in a solvent listed on the Product Information sheet. What can I do?

If the target concentration is within the solubility limit listed on the Product Information sheet, gentle warming and gentle mixing may help dissolve the compound. Rapid temperature changes and harsh mixing may compromise the integrity of the chemical. Some chemicals are temperature sensitive and/or sensitive to oxidation. It is not uncommon for a compound to misbehave and not go into solution even at published concentrations. See “I found different solubility data from different sources. Which one is right?” Still having trouble getting your compound into solution? Please contact our Technical Support scientists.


Q: What can I use to dissolve my compound?

MedKoo's Product data sheets provide solubility data for most compounds using common polar and non-polar solvents. Solvents such as water (protic), PBS (protic), ethanol (protic), DMSO (aprotic), and dimethyl formamide (DMF) (aprotic) are commonly listed. Your specific application may require the use of a solvent that is not listed, and the compatibility of that solvent with your compound may not be known. The choice of appropriate solvent will depend on the polarity of the solvent and polarity of your compound (solute).


A solvent polarity scale derived from Reichardt's dye, representing solvent polarity in correlation with chemical kinetics and equilibria (Sherwood, J. Bio-based solvents for organic synthesis, 2014).


Other factors such as size and crystal structure of your solute may also affect solubility. You may need to heat, stir, or even sonicate your solution for complete dissolution. Be aware that compounds in solution may become unstable. It is best practice to make fresh solutions for your experiments or store pre-made solutions at -80°C.


Q: Can your synthetically produced substances be used in cell culture?

Typically, yes. However, the substances are usually not checked for sterility. If you would like to use the substance in cell culture, we recommend sterile filtration of the stock solution. Furthermore, endotoxin concentration is usually not tested.


Q: How may I obtain a Certificate of Analysis (CoAs), Confirmation of Analysis, or Safety Data Sheet for an item?

CoAs and SDSs are available on our website. You can download from the product web page under “QC and Documents” tab.


Q: How long does a custom synthesis take? How much will it cost?

The lead time and cost of a custom synthesis can vary widely depending on the structure of the compound of interest and complexity of the synthesis. Please contact for any custom inquiry requests.


Q: Once I dissolve a solid compound, how long is it stable?

In general, suppliers do not conduct shelf-life tests on the substances once they have been solubilized. The product descriptions therefore often do not contain any statements regarding the stability of the solutions. The stated stability refers to the undissolved, solid substance. For substances supplied in solution, the stability refers to the substance in the solvent as provided. There is usually no additional data available.


Q: What should I do when my product reaches its expiry date?

If MedKoo still has material from the batch in stock, we will re-QC the material and extend the expiration date when possible. To check if your batch has been extended, please contact our sales staff to allow us to assist you further.