Permethrin vs. Pyrethrum: What’s the Difference?

Permethrin and pyrethrum insecticides are quite similar. It’s no coincidence that their names sound alike; they have similar qualities and chemical composition. They both kill unwanted insects. However, they are not the same thing. So, let’s explore the topic of permethrin versus pyrethrum to see what makes them so different from each other and to find out which one is better for whatever your intended use may be.

Permethrin uses

Permethrin is a synthetic chemical used in insecticides to kill mosquitoes and other insects. It is also used in medications that treat scabies and lice. In animals, it is used to eradicate lice and other parasites which may be in their fur or, even worse, living inside of them.

Permethrin insecticides are available in creams, lotions, sprays, powders, flea collars, and treated clothing. Even though this pesticide can be found in medications and is meant to be applied to the skin, it can cause skin irritation. However, it is not dangerous or unsafe for adults or children over two months of age. Permethrin is, however, highly toxic to aquatic life (e.g., fish, frogs).

Permethrin insecticides should be used only when necessary and in the correct amounts, as is true for all medications and pesticides.

If permethrin is used according to the safety instructions, side effects are unlikely.

Permethrin is also utilized in agriculture where it is used to fight the pests that may infest various different crops. But, as it is a wide spectrum insecticide that is intended to kill various kinds of pests, it also kills beneficial insects such as honey bees. It can also be harmful to aquatic life. Permethrin is used to fight insect pests, such as ticks, which may infect other animals by being applied to the rodent populations which may house these insects. In addition, permethrin is used in tropical areas as a mosquito prevention measure to suppress deadly mosquito-borne illnesses such as malaria. By lining our bedding and clothing with this chemical, we can repel mosquitos and other insects that transmit different illnesses and infections. 

Pyrethrum uses

Pyrethrum is a natural insecticide found within a genus of flowers commonly called chrysanthemums. As it is naturally accessible, pyrethrum has been used for centuries. Moreover, because pyrethrum is a natural plant extract, pyrethrum insecticide is non-synthetic and also can be used on certified organic farms.

Chrysanthemum flower

Chaleow Ngamdee/

Chrysanthemum flowers are dried and crushed so that the active components, called pyrethrin, can be extracted and the insecticide acquired. Nowadays, pyrethrum is combined with other chemicals for greater effectiveness and can be found in many household pest control products.

Even though pyrethrum is natural, pyrethrum insecticides are still dangerous for some animals, especially aquatic animals. Therefore, pyrethrum should be handled with the same amount of caution as synthetic pesticides because its toxic effects are quite similar to those of synthetic pesticides.

People who suffer an over-exposure to pyrethrum can experience side effects such as itchy skin, a runny nose, and even asthma symptoms. People who are sensitive and have allergies should be extra careful around chrysanthemums and pesticides manufactured from them, as they can cause health issues.

The differences between permethrin and pyrethrum

Permethrin and other pyrethroid insecticides are a modified form of pyrethrum. Pyrethrum is the raw, natural form of this insecticide while pyrethroids were created to substitute this strong natural insecticide and to be more stable. Pyrethrum breaks down rapidly in water or when exposed to light. Pyrethroids are more resilient. As an insecticide, pyrethroids are still deadly to bees, even in very small amounts. Therefore, take caution when using them in garden areas or other places frequented by bees.

The main difference between these two insecticides is that permethrin is a synthetic chemical made in laboratories while pyrethrum is a completely natural substance acquired from chrysanthemums.

The effects of both pesticides are quite similar, but, as permethrin is synthetic, it is more stable and effective when exposed to sunlight. For this reason, synthetic permethrin is used in agriculture more often than pyrethrum to protect crops from unwanted insects. Farmers need more stable pesticides which can withstand exposure to sunlight on those sunny, hot summer days.

Both pyrethrum and permethrin have low toxicity to mammals and birds. However, cats can be particularly sensitive to them due to their inability to quickly break them down.

Altogether, the main difference between permethrin and pyrethrum is the way they are produced. One comes from flowers while the other is synthetically manufactured in laboratories and persists longer in the environment.



Thank you. I really appreciate your insight.

david minner

I am a trained agronomist and the information presented with this easy to understand message, especially as it relates to people, pet, and beneficial insects, is very very helpful in making decisions. Thank you.

linda harris

Hello, I haven’t been able to find a commercially made but non-toxic spray for roaches. I used to get one labeled as such, which had only pyrethrum I believe, as a main ingredient.

Are you able to make suggestions? I am looking for a spray to use occasionally to drive them from crevices where they run to hide, etc. I find that peppermint oil mixed with water doesn’t bring them out of hiding, and I don’t think it kills them.


    Please check out our best cockroach sprays article because among the roach sprays listed in this article there are a few that are natural, non-toxic yet also very efficient at driving the roaches away.


How is using thousands of acres of farmland to grow something we can make in a laboratory more eco-friendly? Considering most the two main types of chrysanthemum flowers used for this are grown in Africa, maybe they could be growing food crops instead.

Also, please stop telling your readers to spray for cockroaches unless their goal is to spread them around. Bait is the preferred option for German roaches.


    Hi! We appreciate you seeking out to us and caring about the environment so much, however, I would like to point out that there is a major difference between ”being eco-friendly” and ”solving world hunger”. For something to be called ”eco-friendly”, it should cause no harm to the environment (pollution, etc).
    As for cockroaches, we prefer to give our readers intel on various methods that can be used, so they can make their own decision on which one works best for them. As a matter of fact, we actually have an article about these methods, where your suggestion has also been included.


Thank you so much for the information.


what should I use for ground yellow jacket


    We suggest giving Hot Shot a try.

Leslie Alexander

Hi, can use suggest an indoor spray to eradicate a weevil infestation, not only in the kitchen, but in the couch and upstairs bedroom/bathroom? Is Sawyers Permethrin safe to spray, right before bedtime, and not hurt myself or small dog?


    Hello! Permethrin can be used on weevils, however, I would suggest trying some other methods before. The thing about weevils is that they can sometimes be difficult to fight with pesticides. If the infestation hasn’t gotten too severe, you can try removing them manually (e.g. by using a vacuum).

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