All Photos(3)




MK-933, 22,23-Dihydroavermectin B1
CAS Number:
MDL number:
PubChem Substance ID:

Quality Level




MEK: 50 mg/mL

Featured Industry


Mode of action

cell membrane | interferes

antibiotic activity spectrum



Merck & Co., Inc., Kenilworth, NJ, U.S.

storage temp.


SMILES string




InChI key


Gene Information

Looking for similar products? Visit Product Comparison Guide

Related Categories

General description

Ivermectin is a macro-cyclic lactone, derived from avermectin. It functions as an antiparasitic agent. Ivermectin is used against gastrointestinal roundworms, lungworms, mites and lice. It is used to treat onchocerciasis, strongyloidiasis, ascariasis and filariases.


Ivermectin has been used:
  • in Caenorhabditis elegans fecundity assay
  • in larval development test
  • to measure in vivo topical acaricide activity of compounds in rats
  • to assess its acute and chronic effects to zebrafish
  • in percutaneous drug injection method to treat cystic echinococcosis
  • in liquid chromatography with fluorescence detection method


250 mg in poly bottle
1 g in poly bottle

Biochem/physiol Actions

Positive allosteric modulator of α7 neuronal nicotinic acetylcholine receptor; also modulates glutamate-GABA-activated chloride channels.

Features and Benefits

This compound was developed by Merck & Co., Inc., Kenilworth, NJ, U.S.. To browse the list of other pharma-developed compounds and Approved Drugs/Drug Candidates, click here.
This compound is featured on the Acetylcholine Receptors (Nicotinic) page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here.

Other Notes

Primarily ivermectin B1a.



Hazard Classifications

Acute Tox. 1 Oral - Acute Tox. 3 Dermal - Aquatic Acute 1 - Aquatic Chronic 1 - Carc. 2 - Repr. 1B

Storage Class Code

6.1A - Combustible, acute toxic Cat. 1 and 2 / very toxic hazardous materials

WGK Germany


Flash Point F

Not applicable

Flash Point C

Not applicable

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves

Certificate of Analysis

Certificate of Origin

  1. How does the storage temperature relate to shipping conditions?

    The storage conditions that a Sigma-Aldrich catalog and label recommend for products are deliberately conservative. For many products, long-term storage at low temperatures will increase the time during which they are expected to remain in specification and therefore are labeled accordingly. Where short-term storage, shipping time frame, or exposure to conditions other than those recommended for long-term storage will not affect product quality, Sigma-Aldrich will ship at ambient temperature. The products sensitive to short-term exposure to conditions other than their recommended long-term storage are shipped on wet or dry ice. Ambient temperature shipping helps to control shipping costs for our customers. At any time, our customers can request wet- or dry-ice shipment, but the special handling is at customer expense if our product history indicates that the product is stable for regular shipment. See Shipping and Storage for more information.

  2. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  3. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  4. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  5. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  6. What is the molecular weight of Product No. I8898, Ivermectin?

    This product is a mixture of two submoieties B1A, MW 891.1 and B1B, MW 877.1. It is typically predominantly B1A, so you may use a molecular weight of 890 in your calculations.

  7. What is the solution stability of Ivermectin (Product No. I8898)?

    Stock solutions of Ivermectin in DMSO at a concentration of 10 mM have been found to be stable for 2 weeks at -20°C, according to Shan, Q., et al., in Ivermectin, an Unconventional Agonist of the Glycine Receptor Chloride Channel.  J. Biol. Chem., 276(16), 12556-12564 (2001).

  8. What is the composition of the submoieties B1A and B1B in Product No. I8898, Ivermectin?

    Unfortunately we do not test each lot to determine the composition.  In the past, lots have been ~95% B1A and ~5% B1B; however there will be lot-to-lot variation.

  9. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

Evaluation of the toxicity of 2-aminoimidazole antibiofilm agents using both cellular and model organism systems
Stowe SD, et al.
Drug and Chemical Toxicology, 35(3), 310-315 (2012)
Ivermectin used in percutaneous drug injection method for the treatment of liver hydatid disease in sheep
Hokelek M, et al.
Gastroenterology, 122(4), 957-962 (2002)
R J Martin et al.
International journal for parasitology, 28(6), 849-862 (1998-07-23)
Two of three major types of anthelminitic, the avermectins and the nicotinic agonists, exert their therapeutic effect by an action on ligand-gated membrane ion-channels of nematodes. The avermectins, such as ivermectin, open glutamategated chloride channels which have so far been...
Ivermectin in human medicine
Ottesen EA and Campbell W
The Journal of Antimicrobial Chemotherapy, 34(2), 195-203 (1994)
Simultaneous determination of emamectin and ivermectin residues in Atlantic salmon muscle by liquid chromatography with fluorescence detection
Riet JM, et al.
Journal of AOAC (Association of Official Analytical Chemists) International, 84(5), 1358-1362 (2001)

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service