What is the procedure for NEEM

Neem Oil - An Effective Remedy For House Dust Mites?

Neem oil. By Jaipuria [Public domain], via Wikimedia Commons.

Neem oil is obtained from the seeds of the neem tree (Azadirachta indica A. jus) and used to control pests.

For those with allergies to mites, neem oil products are available that are intended to reduce the mite populations in mattresses, bed linen and upholstery and thus alleviate the allergy symptoms.

But how effective is neem oil as a remedy for house dust mites?

The neem tree

The neem tree or neem tree, also called Indian lilac or magosa, is an evergreen tree. It belongs to the mahogany family. The tree comes from the arid regions of the Indian subcontinent, but is also increasingly used in Africa, America and Australia as a useful or ornamental plant. All parts of the tree can be processed into a wide variety of products.

The neem tree. By pinay06. License: CC-BY-SA-3.0 via Wikimedia Commons.

The herbal extracts that are obtained from neem are very different in their composition. That depends on whether they were made from the leaves, fruits, roots or flowers, the location of the tree, the season or the method of extraction.

The natural neem oil is a yellowish, strong smelling and bitter tasting liquid.

Ingredients of neem oil

At least 34 ingredients are described in the literature. The most important components of neem extracts include azadirachtin, salaninne, nimbin, 6-deacetylnimbine, NIM-76 and quercetin. Azadirachtin and some other ingredients in neem extracts belong to the group of terpenes. Quercetin is a flavonoid, and nimbine is one of the bitter substances in neem oil.

Effect on pests

As the most effective substance against pests in neem oil, researchers have found that Azadirachtin identified.

There are now a number of neem products on the market whose ingredients have been standardized and in which azadirachtin is mostly contained in enriched form. These oils are colorless and odorless.

The starting point of azadirachtin is the chemical similarity to the ecdysteroid (ecdysterone) of the pests. Ecdysteroids are hormones that are found in many insects and arachnids, among others. They regulate the moulting of the animals.

Azadirachtin disrupts the synthesis of chitin and thus the structure of the exoskeleton of insects. The moult cannot go to the end. In this way, neem extracts that contain azadirachtin prevent larvae from developing and insects from pupating. However, the substance is less effective in adult animals.

The substance is broken down quickly and is less toxic to beneficial insects than other insecticides.

Neem oil extracts as a remedy against house dust mites

Neem extracts are offered on the German market as a remedy for house dust mites. These products contain neem oil extracts in varying concentrations.

Neem supplements can reduce the amount of mites. However, there are clear differences in the potency, as a study was able to show (Rembold 2004).

In this 60-day experiment, the effects of 6 preparations on a standardized mite population of 200 mites and 50 eggs were compared. While the number of mites increased to 3550 in the untreated sample, it "only" increased to 2324, 2188, 576 and 533 mites in 4 neem preparations. In two neem oil products, the number of mites fell below the initial value (126 and 28 mites).

The neem oil extracts change the eating behavior, inhibit the growth and reproductive ability of the mites, albeit to different degrees.

No preparation really had a mite-killing effect, such as the substance benzyl benzoate. This confirms the investigations by Öko-Test, which could only show a very limited effectiveness of mite killers (Öko-Test 2004).

Can neem oil be harmful to human health?

There have been isolated cases in which someone has swallowed neem oil and poisoned themselves with it; even people are said to have died because of it. However, these were mostly contaminated oils, natural oil that was not processed further, and other ingredients (such as nimbin and quercetin). Poisoning with the pure substance azadirachtin, which is used to combat mites, is not known.

When the neem oil is burned in lamps, inhalation of the air does not appear to be irritating or toxic to children or adults.

The toxicity of azadirachtin and the commercial products made from this substance (10 percent azadirachtin content) was investigated in 1992 in animal experiments or on the basis of cell cultures. Among other things, rats were mixed with high doses (five milligrams per kilogram) in the food and with albino rabbits one rubbed generously (two milligrams per kilogram) on the skin.

Neither the rats nor the albinos showed symptoms of intoxication. Mild skin irritation occurred in rabbits after the concentrated substance was given to them on the skin and in the eyes. Guinea pigs also got some of it on their skin several times without reacting with sensitization.

Even if neem oil is not acutely toxic if swallowed, there is a lack of scientific studies on the effectiveness and safety in long-term use (Indoor pollution, allergy risk).


Neem oil inhibits the mites' growth and ability to reproduce, albeit to different degrees. Nevertheless, neem supplements do not offer any progress for house dust mite remediation. This has the following reasons:

  • The number of mites only decreases slowly.
  • The mite allergens remain if washing and vacuuming are not carried out in parallel. Treatment with neem oil as the sole remedial measure is not recommended. There is no "immediate effect" for the affected mite allergy sufferer.
  • Above all, there are no studies showing that the preparation has a positive effect on the patient's symptoms. Such controlled long-term studies with effective neem products would, however, be important in order to be able to better evaluate neem oil products.
  • As a first measure to combat dust mites, the bed should be refurbished. The following are helpful here:
    - a special one Encasing (allergen-proof cover) of the mattress and
    - the To wash the bed linen at a minimum of 60 ° C.

Detailed information on cleaning up house dust mites can be found here.