Brand: NOROMECTIN ® 1% w/v Multi Injection


FORMULATION: «injectable» to be administered subcutaneously under the loose skin in front of, or behind, the shoulder in cattle; in the neck in sheep; immediately behind the ear in swine.

ACTIVE INGREDIENT(S): ivermectin: 10 mg/mL (=1.0%)

CHEMICAL CLASS of the active ingredient(s): macrocyclic lactone


CATTLE, SHEEP, SWINE (cattle everywhere; sheep & swine depending on the country)

PARASITES CONTROLLED* (spectrum of activity)

* Country-specific differences may apply: read the product label





*Can be slightly different in some countries: read the product label!

  • Cattle: 200 mcg/kg bw, equivalent to 1 ml/50 kg (=110 lb) bw
  • Sheep: 200 mcg/kg bw, equivalent to 0.5 ml/25 kg (=55 lb) bw
  • Swine: 300 mcg/kg bw, equivalent to 1 ml/33 kg (=75 lb) bw


  • LD50 (acute oral) in rats: ~2500 mg/kg (estimate according to WHO 2009 recommendation)
  • LD50 (acute dermal) in rats: ~660 mg/kg (for the a.i. ivermectin)
  • Estimated hazard class according to the WHO: not applicable for veterinary medicines

Suspected poisoning? Read the article on ivermectin safety in this site.

Withholding period for meat (country-specific differences may apply: read the product label)

  • Cattle: US: 35 days; UK & NZL: 49 days
  • Sheep: EU: 42 days
  • Swine: USA: 18 days; UK & EU: 28 days

In most countries not approved for use on dairy animals producing milk for human consumption.

Non-lactating dairy cattle: In most countries, treat at least 2 months prior to calving.

WARNING !!!: Never use on humans, dogs and cats


Risk of resistance? YES, in gastrointestinal roundworms in sheep (very high), goats (very high) and cattle (high) particularly in:

Resistance of gastrointestinal roundworms to ivermectin in sheep, goats and cattle has been reported almost worldwide, including the USA, UK, Australia and New Zealand. Based on the very abundant and frequent use of ivermectin and other macrocyclic lactones (with cross-resistance to ivermectin) in livestock it must be assumed that resistance of these roundworms to this chemical class will continue spreading and strengthening in the future.

This means that if this product does not achieve the expected efficacy against the mentioned parasites, it may be due to resistance and not to incorrect use, which is usually the most frequent cause of product failure.

Alternative chemical classes/active ingredients to prevent resistance of gastroinitestinal roundworms through product rotation:

These alternative products may not be available in all countries, or may not be available as injectables.

Learn more about resistance and how it develops.


Are the active ingredients of this product ORIGINAL* or GENERICS**?


*Meaning that they are still patent protected and generics are not yet available
**Meaning that they have lost patent protection and may be acquired from manufacturers of generic active ingredients other than the holder of the original patent.

COUNTRIES where this product is marketed (maybe under another TM): USA, Canada, UK, Ireland and other EU countries, New Zealand, etc.
GENERIC BRANDS available? YES, worldwide by the hundreds. Ivermectin 1% injectable is probably the veterinary product with more generic brands worldwide.

Click here to learn more about GENERIC vs. ORIGINAL drugs.

For an overview on the most used antiparasitic injectable brands for livestock click here.


NOROMECTIN 1% w/v Multi Injection is one of the numberless generic brands of the ivermectin 1% injectable formulation, in this case from NORBROOK. It is a generic version of IVOMEC (from MERIAL).

Ivermectin is a broad spectrum parasiticide with efficacy against internal parasites (mainly roundworms) and against external parasites as well (mainly mites, lice, grubs, etc). This is why it is called an endectocide (controls endoparasites and ectoparasites). Ivermectin was the first macrocyclic lactone discovered and introduced in the 1980s by MS&D AgVet (now MERIAL). It is the parasiticide for livestock and pets most widely used worldwide, with probably thousands of generic brands. Ivermectin is probably the best veterinary parasiticide ever developed, highly effective against roundworms and, depending on the delivery form and formulation, also against numerous external parasites (ticksflies, lice, mites, etc.). As all macrocyclic lactonesivermectin used alone is ineffective against tapeworms and flukes, regardless of the delivery form. It is massively used in livestock and horses, less in pets. Ist is also used as a human medicine, against agricultural and household pests and for vector control.

There are also numerous mixtures of ivermectin with other active ingredients, as well as other formulations for topical (pour-on) and oral (drench, feed additives) administration.

It is good to know that not all ivermectin 1% injectable formulations are exactly the same as the original formulation (IVOMEC). There are studies showing that the protective period (residual effect) against some particular parasites is considerably different among such formulations, indicating that they are not really bioequivalent. This can be due to different non-active ingredients in the formulation, different qualities of the active ingredient (e.g. with different by-products), different manufacturing processes, etc. Usually this is considered by the regulatory authorities of each country that issue the approved use instructions of every product, which may be different. It is also important to understand that although the product may control certain parasites, they may not be mentioned in the indications in a particular country simply because they do not occur there: e.g. cattle grubs in Australia and South America, human bot flies in Europe, North America and Australia, etc.

Being one of the best antiparasitics ever developed, ivermectin does not control all parasites of livestock. Unfortunately advertising and even the label of some generic formulations in less developed countries often include unsubstantiated claims. To help preventing confusion and misuse it is useful to know that whatever ivermectin 1% injectable used at the recommended dose DOES NOT CONTROL:

Click here for general information on good practices for the prevention and control of gastrointestinal worms in livestock.


This article IS NOT A PRODUCT LABEL. It offers complementary information that may be useful to veterinary professionals and users that are not familiar with veterinary antiparasitics. 

Information offered in this article has been extracted from publications issued by manufacturers, government agencies (e.g. EMEA, FDA, USDA, etc.) or in the scientific literature. No guarantee is given on its accuracy, integrity, sufficiency, actuality and opportunity, and any liability is denied. Read the site's DISCLAIMER.

In case of doubt contact the manufacturer or a veterinary professional